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Gu, Gang, Ai Guo Wang, Chen Cheng Hu y Hai Chao Liang. "The Impact Analysis of Subsidence on Vegetation Growth in Songzao Mining". Applied Mechanics and Materials 448-453 (octubre de 2013): 805–9. http://dx.doi.org/10.4028/www.scientific.net/amm.448-453.805.
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In this paper, to gradually comprehensive analyze the impact of coal exploration to vegetation growth, Chongqing Songzao Mining was selected as the study area, vegetation index changes of the past decade were analyzed from a macro perspective using three remote sensing data, and then species composition and community structure of different times collapse area was analyzed using microscopic samples investigate. This paper argues that Songzao Mining exploitation of coal resources affected the local forest and grassland vegetation, but not on a wide range of forest and grassland ecosystems adversely affected, the area of forest and grassland ecosystems can carry local failure, and through the self-healing approach ultimately make forest grass ecosystem to stabilize.
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Zhao, Jinling, Jiale Chen, Honghui Wu, Linghao Li y Fengjuan Pan. "Effects of Mowing Frequency on Soil Nematode Diversity and Community Structure in a Chinese Meadow Steppe". Sustainability 13, n.º 10 (17 de mayo de 2021): 5555. http://dx.doi.org/10.3390/su13105555.
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Soil nematodes are one of the most important components in terrestrial ecosystems and the critical factor driving the belowground process. The grasslands of Northeast China have been subject to mowing for ages, which theoretically should have had substantial effects on the processes associated with soil nematodes. However, relevant studies have barely been conducted to date. This study examined variations in soil nematode abundance, biomass, diversity, and community structure, with respect to varying mowing frequencies. The results showed that a higher mowing frequency significantly reduced the abundance of soil nematodes, biomass, diversity, and community structure stability in the ecosystem, while intermediate mowing frequency enhanced these parameters to different extents. Our findings indicate that the changing patterns of the nematode indices with mowing frequency conform to the intermediate disturbance theory. This study provides a theoretical basis for formulating grassland-related management measures and maintaining the stability of grassland ecosystems.
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Beal-Neves, Mariana, Cleusa Vogel Ely, Marjorie Westerhofer Esteves, Betina Blochtein, Regis Alexandre Lahm, Everton L. L. Quadros y Pedro Maria Abreu Ferreira. "The Influence of Urbanization and Fire Disturbance on Plant-floral Visitor Mutualistic Networks". Diversity 12, n.º 4 (3 de abril de 2020): 141. http://dx.doi.org/10.3390/d12040141.
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The biodiversity loss resulting from rising levels of human impacts on ecosystems has been extensively discussed over the last years. The expansion of urban areas promotes drastic ecological changes, especially through fragmentation of natural areas. Natural grassland remnants surrounded by an urban matrix are more likely to undergo disturbance events. Since grassland ecosystems are closely related to disturbances such as fire and grazing, grassland plant communities, pollinators, and their interaction networks may be especially sensitive to urban expansion, because it promotes habitat fragmentation and modifies disturbance regimes. This work evaluated the effect of the level of urbanization and recent history of fire disturbance on grassland plants communities and plant-floral visitor mutualistic networks. We sampled plant communities and floral visitors in 12 grassland sites with different levels of urbanization and time since the last fire event. Sites with higher levels of urbanization showed higher values for plant species richness, floral visitor richness, and network asymmetry. All sampled networks were significantly nested (with one exception), asymmetric, and specialized. In addition, all networks presented more modules than expected by chance. The frequency of fire disturbance events increased with the level of urbanization. Since grassland ecosystems depend on disturbances to maintain their structure and diversity, we inferred that the history of fire disturbance was the mechanism behind the relationship between urbanization and our biological descriptors. Our findings highlight the importance of small and isolated grassland remnants as conservation assets within urban areas, and that the disturbance events that such sites are submitted to may in fact be what maintains their diversity on multiple levels.
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Shao, Keqiang y Guang Gao. "Soil microbial communities of three grassland ecosystems in the Bayinbuluke, China". Canadian Journal of Microbiology 64, n.º 3 (marzo de 2018): 209–13. http://dx.doi.org/10.1139/cjm-2017-0585.
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The microbial community plays an important role in soil nutrient cycles and energy transformations in alpine grassland. In this study, we investigated the composition of the soil microbial community collected from alpine cold swamp meadow (ASM), alpine cold meadow (AM), and alpine cold desert steppe (ADS) within the Bayinbuluke alpine grassland, China, using Illumina amplicon sequencing. Of the 147 271 sequences obtained, 36 microbial phyla or groups were detected. The results showed that the ADS had lower microbial diversity than the ASM and AM, as estimated by the Shannon index. The Verrucomicrobia, Chloroflexi, Planctomycetes, Proteobacteria, and Actinobacteria were the predominant phyla in all 3 ecosystems. Particularly, Thaumarchaeota was only abundant in ASM, Bacteroidetes in AM, and Acidobacteria in ADS. Additionally, the predominant genus also differed with each ecosystem. Candidatus Nitrososphaera was predominant in ADS, the Pir4 lineage in ASM, and Sphingomonas in AM. Our results indicated that the soil microbial community structure was different for each grassland ecosystem in the Bayinbuluke.
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Shen, Ju-Pei, Maryam Esfandbod, Steve A. Wakelin, Gary Bacon, Qiaoyun Huang y Chengrong Chen. "Changes in bacterial community composition across natural grassland and pine forests in the Bunya Mountains in subtropical Australia". Soil Research 57, n.º 8 (2019): 825. http://dx.doi.org/10.1071/sr19111.
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Tree and grass species coexist in many ecosystems worldwide and support multiple ecosystem functions and services. However, the distribution of bacterial communities and factors driving coexistence in tree–grass associations and their ecosystem functions remain poorly understood. In this study, the distribution of soil bacteria and their link to changes in abiotic factors were investigated in adjacent montane grassland (C4 plants) and pine forest (bunya pine and hoop pine; C3 plants) sites in the Bunya Mountains, subtropical Australia. Different vegetation (grassy balds and forest) had a substantial effect on terrestrial ecosystem properties, with higher levels of soil nutrients (e.g. total nitrogen (N), total phosphorus (P)) and electrical conductivity (EC), and lower δ13C values and pH under forests compared with grassland. Bacterial α-diversity (total species per operational taxonomic unit richness) did not differ between grassland and pine forest sites, whereas strong shifts in the bacterial community composition and structure were evident. Patterns in bacterial community structure were strongly associated with changes in soil pH, EC, total P and δ13C. Different bacterial groups associated with pine forest (Gammaproteobacteria and Alphaproteobacteria) and grassland (Acidobacteria and Verrucomicrobia) were identified as key groups contributing to the segregation of these two ecosystems in the Bunya Mountains. These findings suggest that heterogeneity in soil edaphic properties (e.g. key nutrients) likely contributed to variation in bacterial β-diversity of grassland and pine forest, which has potential implications for species coexistence and ecosystem function in montane eastern Australia.
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Juárez-Juárez, Brenda, Mariana Cuautle, Citlalli Castillo-Guevara, Karla López-Vázquez, María Gómez-Ortigoza, María Gómez-Lazaga, Cecilia Díaz-Castelazo, Carlos Lara, Gibrán R. Pérez-Toledo y Miguel Reyes. "Neither ant dominance nor abundance explain ant-plant network structure in Mexican temperate forests". PeerJ 8 (7 de diciembre de 2020): e10435. http://dx.doi.org/10.7717/peerj.10435.
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Background Ant-plant mutualistic networks tend to have a nested structure that contributes to their stability, but the ecological factors that give rise to this structure are not fully understood. Here, we evaluate whether ant abundance and dominance hierarchy determine the structure of the ant-plant networks in two types of vegetation: oak and grassland, in two temperate environments of Mexico: Flor del Bosque State Park (FBSP) and La Malinche National Park (MNP). We predicted that dominant and abundant ant species make up the core, and submissives, the periphery of the network. We also expected a higher specialization level in the ant trophic level than in plant trophic level due to competition among the ant species for the plant-derived resources. Methods The ant-plant interaction network was obtained from the frequency of ant-plant interactions. We calculated a dominance hierarchy index for the ants using sampling with baits and evaluated their abundance using pitfall traps. Results In MNP, the Formica spp. species complex formed the core of the network (in both the oak forest and the grassland), while in FBSP, the core species were Prenolepis imparis (oak forest) and Camponotus rubrithorax (grassland). Although these core species were dominant in their respective sites, they were not necessarily the most dominant ant species. Three of the four networks (oak forest and grassland in FBSP, and oak forest in MNP) were nested and had a higher number of plant species than ant species. Although greater specialization was observed in the ant trophic level in the two sites and vegetations, possibly due to competition with the more dominant ant species, this was not statistically significant. In three of these networks (grassland and oak forest of MNP and oak forest of FBSP), we found no correlation between the dominance hierarchy and abundance of the ant species and their position within the network. However, a positive correlation was found between the nestedness contribution value and ant dominance hierarchy in the grassland of the site FBSP, which could be due to the richer ant-plant network and higher dominance index of this community. Conclusions Our evidence suggests that ant abundance and dominance hierarchy have little influence on network structure in temperate ecosystems, probably due to the species-poor ant-plant network and a dominance hierarchy formed only by the presence of dominant and submissive species with no intermediate dominant species between them (absence of gradient in hierarchy) in these ecosystems.
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Gajic, Bosko, Branka Kresovic, Snezana Dragovic, Zorica Sredojevic y Ranko Dragovic. "Effect of land use change on the structure of Gleyic Fluvisols in western Serbia". Journal of Agricultural Sciences, Belgrade 59, n.º 2 (2014): 151–60. http://dx.doi.org/10.2298/jas1402151g.
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Changes in land use can significantly affect aggregate distribution and water stability of structural aggregates. This study was conducted in the Kolubara River Valley, Western Serbia, to determine the effects of land use changes on composition and water stability of aggregates in humus horizons (0-30 cm) of noncarbonated Gleyic Fluvisols. This study was conducted at nine sites, where each site contained two adjacent land uses of natural grassland and arable land which underwent crop rotation for >100 years. Soil samples were taken from depths of 0-10, 10-20 and 20-30 cm for each land use. When the grassland was converted into arable land, the content of the agronomically most valuable aggregates (0.25-10 mm) of cultivated soils for a depth of 0-30 cm was significantly reduced by 22-40%, while the percentage of cloddy aggregates (>10 mm) increased by 41-68%, compared to grassland. In addition, the long-term arable soil had significantly (p<0.05) lower aggregate stability, determined by wet sieving, than grassland. The lowest aggregate stability was found in aggregates > 3 mm. Their content is ? 2.3 times lower in arable soil (12.6%) than in grassland (28.6%) at a depth of 0-10 cm. In addition, meanweight diameters of dry and wetstable aggregates and structure coefficient showed significant differences between land use at a depth of 0-30 cm. The results showed that the conversion of natural grassland to arable land in the lowland ecosystems of Western Serbia degraded aggregate distribution and stability.
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Rose, Sarah Jane y P. Charles Goebel. "Short-term Impacts of Prescribed Burning on the Spider Community (Order: Araneae) in a Small Ohio Grassland". Ohio Journal of Science 115, n.º 2 (9 de noviembre de 2015): 79. http://dx.doi.org/10.18061/ojs.v115i2.4901.
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Prescribed burning is a management tool that is widely accepted for prairie management and restoration, yet little is known how burning may impact the spider community. Although it is generally thought that prescribed burning may alter the spider community composition and structure, few studies have examined these shifts in a controlled manner with both a burned grassland and a nearby unburned companion grassland. On October 25, 2014 we conducted a prescribed burn of a grassland at the Gwynne Conservation Area, London, Ohio. Spiders were sampled using pitfall traps for four weeks pre-burn and six weeks post-burn in both the treatment grassland and adjacent unburned grassland. A total of 298 spiders were collected from sixteen families, over 60% of which were in the family Lycosidae. Overall, we found the prescribed burn did not significantly alter the abundance or diversity of spiders collected, and interestingly it appears the community composition of the unburned grassland changed more over the sample period than the burned grassland. Anecdotal observations also suggest that some spiders are capable of surviving the fire in situ. As we continue to study these communities, we will develop a better understanding of role that prescribed burning plays in regulating the structure and composition of the spider communities. Such information is important to develop process-based restoration and management practices in grassland ecosystems.
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Ghioca-Robrecht, D. M. y L. M. Smith. "The role of Spadefoot Toad tadpoles in wetland trophic structure as influenced by environmental and morphological factors". Canadian Journal of Zoology 89, n.º 1 (enero de 2011): 47–59. http://dx.doi.org/10.1139/z10-093.
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Larval amphibians reach high densities in playa wetlands in the Southern Great Plains (SGP), USA, and thus may influence the entire structure and function of these ecosystems. We investigated whether both carnivorous and omnivorous morphotypes of Spadefoot Toad tadpoles (New Mexico Spadefoot, Spea multiplicata (Cope, 1863), and Plains Spadefoot, Spea bombifrons (Cope, 1863)) would exhibit a macrophagous feeding behavior that would allow them to occupy several trophic levels in playas. We also compared tadpole diets and foregut widths as influenced by the land use surrounding playas (cultivated versus grassland watersheds), year (dry versus wet year), and body size (snout-to-vent length). Tadpole diets were dominated by detritus and diatoms and tadpole foreguts increased with body size. Generally, more arthropods and less cyanobacteria were found in Spea tadpole diets as tadpoles grew larger, suggesting they influence different trophic levels with age. Foreguts were wider in carnivores than omnivores, suggesting carnivores had increased ability to ingest larger prey. Also, omnivores had wider foreguts in cropland than grassland playas, suggesting they ingest larger food items in cropland playas. From estimates of the amounts of invertebrates, detritus, and algae consumed by Spea tadpoles, we demonstrate that these larvae influence the entire trophic structure of wetland ecosystems.
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Macharia, J. N. M. y S. K. Imbamba. "Ecological Studies of Some Grasslands in Kenya: Structure and Net Primary Productivity in Four Grassland Ecosystems". East African Agricultural and Forestry Journal 57, n.º 1 (julio de 1991): 75–88. http://dx.doi.org/10.1080/00128325.1991.11663140.
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Duru, M., C. Jouany, X. Le Roux, M. L. Navas y P. Cruz. "From a conceptual framework to an operational approach for managing grassland functional diversity to obtain targeted ecosystem services: Case studies from French mountains". Renewable Agriculture and Food Systems 29, n.º 3 (20 de septiembre de 2013): 239–54. http://dx.doi.org/10.1017/s1742170513000306.
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AbstractResearch to understand and manage ecosystems to supply services has recently spurred a functional view of their biodiversity. In particular, approaches based on functional traits rather than species diversity are increasingly used to reflect interactions between organisms and their environment. These approaches bring a functional perspective to the study of community structure responses to disturbances and resources, and of their effects on ecosystem functioning and services. From an academic perspective, we propose a conceptual framework based on species functional traits to better infer how grassland management practices (fertilization, defoliation regime) along with abiotic factors influence plant, animal and microbial community composition and a range of services in grassland ecosystems. The core of the framework relies on combinations of plant functional traits and associated microbial features that specifically respond to environmental and management factors and influence ecosystem services. To overcome stakeholders’ difficulty in applying the concept of functional traits, we propose an operational approach implying the mapping of plant communities distributed into five plant functional types (PFTs). The approach was used for fields in grassland-based livestock farms from two French grassland networks. We evaluated its ability to predict a range of services including forage provision and non-market services according to environmental and management drivers. PFT-based plant community composition predicted forage services reasonably well but responded weakly to environmental gradients. To cope with the observed limitations of current predictive approaches, we suggest including soil microbial functional types and adaptive management rather than using a prescriptive scheme.
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Tsafack, Noelline, François Rebaudo, Hui Wang, Dávid D. Nagy, Yingzhong Xie, Xinpu Wang y Simone Fattorini. "Carabid community structure in northern China grassland ecosystems: Effects of local habitat on species richness, species composition and functional diversity". PeerJ 6 (9 de enero de 2019): e6197. http://dx.doi.org/10.7717/peerj.6197.
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Background Most carabid beetles are particularly sensitive to local habitat characteristics. Although in China grasslands account for more than 40% of the national land, their biodiversity is still poorly known. The aim of this paper is to identify the main environmental characteristics influencing carabid diversity in different types of grassland in northern China. Methods We investigated the influence of vegetation (plant biomass, cover, density, height and species richness), soil (bulk density, above ground litter, moisture and temperature) and climate (humidity, precipitation and temperature) on carabid community structure (species richness, species composition and functional diversity—measured as body size, movement and total diversity) in three types of grasslands: desert, typical and meadow steppes. We used Canonical correspondence analysis to investigate the role of habitat characteristics on species composition and eigenvector spatial filtering to investigate the responses of species richness and functional diversities. Results We found that carabid community structure was strongly influenced by local habitat characteristics and particularly by climatic factors. Carabids in the desert steppe showed the lowest richness and functional diversities. Climate predictors (temperature, precipitation and humidity) had positive effects on carabid species richness at both regional and ecosystem levels, with difference among ecosystems. Plant diversity had a positive influence on carabid richness at the regional level. Soil compaction and temperature were negatively related to species richness at regional level. Climatic factors positively influenced functional diversities, whereas soil temperature had negative effects. Soil moisture and temperature were the most important drivers of species composition at regional level, whereas the relative importance of the various environmental parameters varied among ecosystems. Discussion Carabid responses to environmental characteristics varied among grassland types, which warns against generalizations and indicates that management programs should be considered at grassland scale. Carabid community structure is strongly influenced by climatic factors, and can therefore be particularly sensitive to ongoing climate change.
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NAETH, M. A., R. L. ROTHWELL, D. S. CHANASYK y A. W. BAILEY. "GRAZING IMPACTS ON INFILTRATION IN MIXED PRAIRIE AND FESCUE GRASSLAND ECOSYSTEMS OF ALBERTA". Canadian Journal of Soil Science 70, n.º 4 (1 de noviembre de 1990): 593–605. http://dx.doi.org/10.4141/cjss90-062.
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Infiltration capacity is generally reduced with increased grazing intensity and reduced range condition, mainly through vegetation and litter removal, soil structure deterioration, and compaction. Only one study has documented the effect of grazing on Canadian rangelands, necessitating further investigation. In this study, impacts of long-term grazing on infiltration were assessed in mixed prairie and fescue grassland ecosystems of southern and central Alberta, Canada. Grazing regimes were of light to very heavy intensities, grazed early, late, and continuously during the growing season. Ungrazed controls were evaluated at each site. Infiltration was measured with double ring infiltrometers. Heavy intensity and/or early season grazing had greater impact on infiltration than light intensity and/or late season grazing. In mixed prairie, initial and steady state infiltration rates in the control were 1.5 and 1.7 times higher, respectively, than those in the early season grazed treatment. In parkland fescue, initial rates were lowest in June grazed treatments and steady state rates were highest in light autumn grazed and control treatments. Initial infiltration rates in foothills fescue control and light grazed treatments were 1.5–2.3 times those in heavy and very heavy grazed treatments. Steady state rates were 1.5–2 times higher in light grazed and control treatments than in moderate, heavy, and very heavy grazed treatments. Key words: Infiltration, infiltration rate, grazing, rangelands
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Bogovin, A. y M. Ptashnik. "Influence of agrotechnical methods upon ecobiomorphic structure and productivity of self-recovered grassland ecosystems of Forest-steppe". Visnyk agrarnoi nauky 96, n.º 6 (15 de junio de 2018): 12–18. http://dx.doi.org/10.31073/agrovisnyk201806-02.
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Nagy, Z., K. Pintér, M. Pavelka, E. Darenová y J. Balogh. "Carbon balance of surfaces vs. ecosystems: advantages of measuring eddy covariance and soil respiration simultaneously in dry grassland ecosystems". Biogeosciences Discussions 8, n.º 1 (4 de febrero de 2011): 941–73. http://dx.doi.org/10.5194/bgd-8-941-2011.
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Abstract. An automated open system for measurement of soil CO2 efflux (Rsc) was developed and calibrated against known fluxes and tested in the field, while measuring soil respiration also by the gradient method (Rsg) at a dry sandy grassland (Bugac, Hungary). Ecosystem respiration (Reco) was measured by the eddy covariance technique. Small chamber size (5 cm in diameter) of the chamber system made it possible to use the chambers also in vegetation gaps, thereby avoiding the necessity of removing shoots, the disturbance of the spatial structure of vegetation and the upper soil layer. Low air flow rates associated with small chamber volume and chamber design allowed the overpressure range to stabilize between 0.05–0.12 Pa. While the correlation between ecosystem and soil CO2 efflux rates as measured by the independent methods was significant, Reco rates were similar or even lower than Rsc in the low flux (up to 2 μmol CO2 m−2 s−1) range, probably due to the larger than assumed storage flux. The gradient method showed both up and downward CO2 fluxes originating from the main rooting zone after rains. Downward fluxes within the soil profile amounted to 15% of the simultaneous upward fluxes and to ~ 7.6% of the total (upward) effluxes during the 3 months study. The upper 5 cm soil layer contributed to ~ 50% of the total soil CO2 efflux. The continuously operated automatic open chamber system and the gradient system makes possible the detection of situations when the eddy system underestimates Reco, gives the lower limit of underestimation (chamber system) and helps in quantifying the downward flux component of soil respiration (gradient method) between the soil layers. These latter (downward) fluxes are expected to seriously affect (1) the Reco vs. temperature response functions and (2) the net ecosystem exchange of CO2 (NEE) vs. photon flux density response functions, therefore potentially affecting also the gap filling procedures and to led to a situation (3) when the measured surface and the real time ecosystem fluxes will necessarily differ in the short term. Simultaneous measurements of Reco and soil CO2 effluxes may reveal the time and degree of the above decoupling, thereby contributing to decrease uncertainty, associated with eddy flux measurements over flat terrains. While the correlation between chamber fluxes and gradient fluxes was strong, gradient fluxes were generally larger than the flux from chambers. Calibration of gradient flux system by chamber effluxes is proposed.
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Nagy, Z., K. Pintér, M. Pavelka, E. Darenová y J. Balogh. "Carbon fluxes of surfaces vs. ecosystems: advantages of measuring eddy covariance and soil respiration simultaneously in dry grassland ecosystems". Biogeosciences 8, n.º 9 (9 de septiembre de 2011): 2523–34. http://dx.doi.org/10.5194/bg-8-2523-2011.
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Abstract. An automated open system for measurement of soil CO2 efflux (Rsc) was developed and calibrated against known fluxes. The system was tested in the field, while estimating soil respiration simultaneously by the gradient method (Rsg) at a dry, sandy grassland site (Bugac, Hungary). Ecosystem respiration (Rego) was measured using the eddy covariance technique. The small chamber size (5 cm in diameter) made it possible to use the chambers in vegetation gaps, thereby avoiding the necessity of removing shoots and disturbing the spatial structure of vegetation and the upper soil layer. Low air flow rates associated with small chamber volume and chamber design allowed the overpressure range to stabilize between 0.05–0.12 Pa. The correlation between ecosystem and soil CO2 efflux rates as measured by the independent methods was significant, Reco rates were similar or even lower than Rsc in the low flux (up to 2 μmol CO2 m−2 s−1) range but the differences were within the uncertainty limits for the two fluxes. Rsc from trenched and non-trenched plots amounted to 16 % and 44 % of Reco, respectively. The gradient method showed both up and downward CO2 fluxes originating from the main rooting zone after rains. Diffusive retardation played a smaller role than CO2 production considering the soil air CO2 concentration increase after rains in a given layer. Downward fluxes within the soil profile amounted to 15 % of the simultaneous upward fluxes and to ~7.6 % of the total (upward) effluxes during the 3-month study. The upper 5 cm soil layer contributed to ~50 % of the total soil CO2 efflux. Downward fluxes are expected to seriously affect (1) the Reco vs. temperature response functions and (2) the net ecosystem exchange of CO2 (NEE) vs. photon flux density response functions, therefore potentially affecting the gap filling procedures and to lead to a situation (3) when the measured surface and the real time ecosystem fluxes will necessarily differ in the short term. Simultaneous measurements of Reco and soil CO2 effluxes may reveal the timing and magnitude of the decoupling, thereby contributing to decreasing uncertainty associated with eddy flux measurements over flat terrains. While the correlations between CO2 effluxes measured by independent systems are strong, Rsg was generally larger than Rsc or Reco, mainly due to overestimation of effective diffusivity in the soil.
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Tu, Qichao, Mengting Yuan, Zhili He, Ye Deng, Kai Xue, Liyou Wu, Sarah E. Hobbie, Peter B. Reich y Jizhong Zhou. "Fungal Communities Respond to Long-Term CO2Elevation by Community Reassembly". Applied and Environmental Microbiology 81, n.º 7 (23 de enero de 2015): 2445–54. http://dx.doi.org/10.1128/aem.04040-14.
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ABSTRACTFungal communities play a major role as decomposers in the Earth's ecosystems. Their community-level responses to elevated CO2(eCO2), one of the major global change factors impacting ecosystems, are not well understood. Using 28S rRNA gene amplicon sequencing and co-occurrence ecological network approaches, we analyzed the response of soil fungal communities in the BioCON (biodiversity, CO2, and N deposition) experimental site in Minnesota, USA, in which a grassland ecosystem has been exposed to eCO2for 12 years. Long-term eCO2did not significantly change the overall fungal community structure and species richness, but significantly increased community evenness and diversity. The relative abundances of 119 operational taxonomic units (OTU; ∼27% of the total captured sequences) were changed significantly. Significantly changed OTU under eCO2were associated with decreased overall relative abundance of Ascomycota, but increased relative abundance of Basidiomycota. Co-occurrence ecological network analysis indicated that eCO2increased fungal community network complexity, as evidenced by higher intermodular and intramodular connectivity and shorter geodesic distance. In contrast, decreased connections for dominant fungal species were observed in the eCO2network. Community reassembly of unrelated fungal species into highly connected dense modules was observed. Such changes in the co-occurrence network topology were significantly associated with altered soil and plant properties under eCO2, especially with increased plant biomass and NH4+availability. This study provided novel insights into how eCO2shapes soil fungal communities in grassland ecosystems.
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Barančíková, Gabriela, Jarmila Makovníková y Ján Halas. "Effect of land use change on soil organic carbon". Agriculture (Polnohospodárstvo) 62, n.º 1 (1 de abril de 2016): 10–18. http://dx.doi.org/10.1515/agri-2016-0002.
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Abstract The direction of changes and conversion of soil organic carbon (SOC) is in most current ecosystems influenced by human activity. Soil Science and Conservation Research Institute is responsible for monitoring the agricultural soils in a five-year cycle. One part of the soil monitoring involves the determination of the soil organic carbon (SOC) storage. Further, we followed the conversion of arable land on grassland during more than 20 years of monitoring period at some locations where changes in land use occurred. Ten places on basic network and 2 places on key monitoring localities in which arable land have been converted into grassland were identified. About 50 percent of studied soils converted into permanent grassland were Cambisols. The other converted soil types were Luvic Stagnosol, Stagnic Regosol, Mollic Fluvisol, and Stagnic Luvisol. The results showed that after the third monitoring cycle (2002), increase of SOC was observed in all the localities, with the change in land use. Statistical parameter (t-test) confirmed significant differences between the set of average SOC values before and after the land use conversion. The chemical structure of humic acids (HA) isolated from arable soil and permanent grassland indicated increasing of aliphatic carbon content in grassland HA. More aromatic and stabile were HA isolated from arable soils.
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Retallack, Gregory J. "Middle Miocene fossil plants from Fort Ternan (Kenya) and evolution of African grasslands". Paleobiology 18, n.º 4 (1992): 383–400. http://dx.doi.org/10.1017/s0094837300010964.
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New evidence from fossil plants at the Middle Miocene fossil quarry near Fort Ternan, Kenya, together with that from paleosols, allow reconstruction of a mosaic of early successional woodland (on Dhero paleosols), grassy woodland (on Chogo clay eroded phase and ferruginized nodule variant paleosols) and wooded grassland (on type Chogo and Onuria clay paleosols). This grassy open vegetation was on a high plateau of phonolite at the foot of a carbonatite-nephelinite stratovolcano, which probably supported dry Afromontane forest, alpine meadows, and marsh. This earliest savanna-mosaic vegetation yet documented from Africa, was probably recruited from dry lateritic soils elsewhere in Africa during climatic drying and cooling some 15 Ma. These early grassland ecosystems were very different from Early Miocene forest ecosystems of East Africa, but not altogether like modern grasslands either. Already present were grasses with dense growth and rich in silica bodies, and abundant antelope with moderately high crowned teeth and cursorial limb structure. These mammalian adaptations to grasslands, however, were not nearly so pronounced as they are in modern African grassland faunas, which include zebra and other Asiatic immigrants, as well as antelope. Grasses of the subfamily Chloridoideae and supertribe Panicanae were common in tropical Africa by Middle Miocene time, if not much earlier, but there is not yet evidence so far back in time for the grass supertribe Andropogonae which is now dominant in seasonally arid, overgrazed, and burned African grasslands.
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Faith, J. Tyler, John Rowan y Andrew Du. "Early hominins evolved within non-analog ecosystems". Proceedings of the National Academy of Sciences 116, n.º 43 (7 de octubre de 2019): 21478–83. http://dx.doi.org/10.1073/pnas.1909284116.
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Present-day African ecosystems serve as referential models for conceptualizing the environmental context of early hominin evolution, but the degree to which modern ecosystems are representative of those in the past is unclear. A growing body of evidence from eastern Africa’s rich and well-dated late Cenozoic fossil record documents communities of large-bodied mammalian herbivores with ecological structures differing dramatically from those of the present day, implying that modern communities may not be suitable analogs for the ancient ecosystems of hominin evolution. To determine when and why the ecological structure of eastern Africa’s herbivore faunas came to resemble those of the present, here we analyze functional trait changes in a comprehensive dataset of 305 modern and fossil herbivore communities spanning the last ∼7 Myr. We show that nearly all communities prior to ∼700 ka were functionally non-analog, largely due to a greater richness of non-ruminants and megaherbivores (species >1,000 kg). The emergence of functionally modern communities precedes that of taxonomically modern communities by 100,000s of years, and can be attributed to the combined influence of Plio-Pleistocene C4 grassland expansion and pulses of aridity after ∼1 Ma. Given the disproportionate ecological impacts of large-bodied herbivores on factors such as vegetation structure, hydrology, and fire regimes, it follows that the vast majority of early hominin evolution transpired in the context of ecosystems that functioned unlike any today. Identifying how past ecosystems differed compositionally and functionally from those today is key to conceptualizing ancient African environments and testing ecological hypotheses of hominin evolution.
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Zhu, Juntao, Yangjian Zhang, Wenfeng Wang, Xian Yang, Ning Chen, Ruonan Shen, Li Wang y Lin Jiang. "Species turnover drives grassland community to phylogenetic clustering over long-term grazing disturbance". Journal of Plant Ecology 13, n.º 2 (23 de diciembre de 2019): 157–64. http://dx.doi.org/10.1093/jpe/rtz057.
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Abstract Aims Grazing exerts profound effects on grassland ecosystem service and functions by regulating species composition and diversity, and structuring community assembly worldwide. However, adaptions of phylogenetic diversity and phylogenetic community structure to long-term grazing disturbance remain poorly studied, especially for ecosystems distributed in extreme environments. Methods Here, we conducted an experiment with multigrazing intensities to explore the impacts of grazing disturbance on plant phylogenetic diversity and community structure in an alpine grassland of the Tibetan Plateau. Important Findings Grazing disturbance enriched plant species richness (SR), and stimulated species turnover from regional species pool, consequently changing community species composition. Under low intensities, grazing exerted no obvious effects on phylogenetic diversity and community structure, whereas communities changed from overdispersion to clustering under high grazing intensity. High grazing intensity resulted in stronger environmental filtering, which consequently selected those species with high resilience to grazing disturbance. The observed clustering structure was associated with the colonizing species which were closely related to resident species, and locally extinct species, and distantly related to residents. At the plant functional trait level, high grazing intensity increased species colonization largely by altering the effect of root depth on species colonization compared to light grazing. Our results highlight that solely utilization of SR and diversity cannot fully represent grassland communities responses to grazing. The effects of species turnover on community phylogenetic diversity and structure are entailed to be explored in the future grazing studies.
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Tsafack, Noelline, Yingzhong Xie, Xinpu Wang y Simone Fattorini. "Influence of Climate and Local Habitat Characteristics on Carabid Beetle Abundance and Diversity in Northern Chinese Steppes". Insects 11, n.º 1 (24 de diciembre de 2019): 19. http://dx.doi.org/10.3390/insects11010019.
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Carabids are an important insect group in grassland ecosystems and are involved in numerous ecosystem services. Steppes are the most widespread ecosystems in China, but they are under increasing degradation. Despite their importance, little is known about the relationships between environmental variables and carabid community structure in Chinese steppes. We studied the effects of fine-scale factors (soil and vegetation) and coarse-scale factors (climate) on carabid community parameters (abundance, richness, diversity, dominance, and evenness) in three types of steppes (desert, typical, and meadow steppes) in northern China. Carabid communities responded to environmental factors in different ways according to the type of steppe. Climate factors were the most important drivers of community structure, whereas the effects of soil and vegetation were less important. Desert steppe showed the lowest carabid abundance, richness, diversity, and evenness, and the highest dominance. This community is relatively simple and strongly dominated by a few species adapted to the severe conditions of this environment. Typical and meadow steppes showed carabid communities with a more complex structure. As expected on the basis of environmental severity, the most severe ecosystem (i.e., the desert) was only influenced by climatic factors, whereas a certain influence of biotic factors emerged in the other ecosystems.
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Ibañez, Mercedes, María José Leiva, Cristina Chocarro, Salvador Aljazairi, Àngela Ribas y Maria-Teresa Sebastià. "Tree—Open Grassland Structure and Composition Drive Greenhouse Gas Exchange in Holm Oak Meadows of the Iberian Peninsula". Agronomy 11, n.º 1 (28 de diciembre de 2020): 50. http://dx.doi.org/10.3390/agronomy11010050.
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Iberian holm oak meadows are savannah-like ecosystems that result from traditional silvo-pastoral practices. However, such traditional uses are declining, driving changes in the typical tree—open grassland structure of these systems. Yet, there are no studies integrating the whole ecosystem—including the arboreal and the herbaceous layer—as drivers of greenhouse gas (GHG: CO2, CH4 and N2O) dynamics. Here, we aimed at integrating the influence of tree canopies and interactions among plant functional types (PFT: grasses, forbs, and legumes) of the herbaceous layer as GHG exchange drivers. For that purpose, we performed chamber-based GHG surveys in plots dominated by representative canopy types of Iberian holm oak meadows, including Quercus species and Pinus pinea stands, the last a common tree plantation replacing traditional stands, and unraveled GHG drivers through a diversity-interaction model approach. Our results show the tree–open grassland structure, especially drove CO2 and N2O fluxes, with higher emissions under the canopy than in the open grassland. Emissions under P. pinea canopies are higher than those under Quercus species. In addition, the inclusion of diversity and compositional terms of the herbaceous layer improve the explained variability, with legumes enhancing CO2 uptake and N2O emissions. Changes in the tree cover and tree species composition, in combination with changes in the structure and composition of the herbaceous layer, will imply deep changes in the GHG exchange of Iberian holm oak meadows. These results may provide some guidelines to perform better management strategies of this vast but vulnerable ecosystem.
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Butler, Jack y Jerrold Dodd. "Characterization of Relict Communities For Monitoring Park Ecosystems in Glen Canyon National Recreation Area". UW National Parks Service Research Station Annual Reports 13 (1 de enero de 1989): 67–69. http://dx.doi.org/10.13001/uwnpsrc.1989.2785.
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Grazing by domestic livestock is authorized on the Glen Canyon National Recreation Area and occurs on about 80% of the NRA lands. Concern over competing land uses has generated considerable interest in the direct and indirect effects of grazing on community structure and function (Kleiner and Harper 1972, 1977, Loope 1977, Jefferies and Klopatek 1987). The primary objectives of this study are to: (1) identify and evaluate the abiotic and biotic factors influencing the stucture and species composition of relict and grazed pinyonÂjuniper, black brush ricegrass, and ricegrass grassland communities, and (2) select, refine and validate a system that can be used to field monitor condition and trend of relict and grazed communities.
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Wakelin, Steven A., Barbara I. P. Barratt, Emily Gerard, Adrienne L. Gregg, Eoin L. Brodie, Gary L. Andersen, Todd Z. DeSantis et al. "Shifts in the phylogenetic structure and functional capacity of soil microbial communities follow alteration of native tussock grassland ecosystems". Soil Biology and Biochemistry 57 (febrero de 2013): 675–82. http://dx.doi.org/10.1016/j.soilbio.2012.07.003.
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Checinska Sielaff, Aleksandra, Racheal N. Upton, Kirsten S. Hofmockel, Xia Xu, H. Wayne Polley y Brian J. Wilsey. "Microbial community structure and functions differ between native and novel (exotic-dominated) grassland ecosystems in an 8-year experiment". Plant and Soil 432, n.º 1-2 (10 de septiembre de 2018): 359–72. http://dx.doi.org/10.1007/s11104-018-3796-1.
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Wang, Shaokun, Xiaoan Zuo, Tala Awada, Eduardo Medima-Roldán, Keting Feng, Ping Yue, Jie Lian, Shenglong Zhao y Huan Cheng. "Changes of soil bacterial and fungal community structure along a natural aridity gradient in desert grassland ecosystems, Inner Mongolia". CATENA 205 (octubre de 2021): 105470. http://dx.doi.org/10.1016/j.catena.2021.105470.
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Zhang, Mei, Dianpeng Li, Xuyang Wang, Maidinuer Abulaiz, Pujia Yu, Jun Li, Xinping Zhu y Hongtao Jia. "Conversion of alpine pastureland to artificial grassland altered CO2 and N2O emissions by decreasing C and N in different soil aggregates". PeerJ 9 (14 de julio de 2021): e11807. http://dx.doi.org/10.7717/peerj.11807.
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Background The impacts of land use on greenhouse gases (GHGs) emissions have been extensively studied. However, the underlying mechanisms on how soil aggregate structure, soil organic carbon (SOC) and total N (TN) distributions in different soil aggregate sizes influencing carbon dioxide (CO2), and nitrous oxide (N2O) emissions from alpine grassland ecosystems remain largely unexplored. Methods A microcosm experiment was conducted to investigate the effect of land use change on CO2and N2O emissions from different soil aggregate fractions. Soil samples were collected from three land use types, i.e., non-grazing natural grassland (CK), grazing grassland (GG), and artificial grassland (GC) in the Bayinbuluk alpine pastureland. Soil aggregate fractionation was performed using a wet-sieving method. The variations of soil aggregate structure, SOC, and TN in different soil aggregates were measured. The fluxes of CO2 and N2O were measured by a gas chromatograph. Results Compared to CK and GG, GC treatment significantly decreased SOC (by 24.9–45.2%) and TN (by 20.6–41.6%) across all soil aggregate sizes, and altered their distributions among soil aggregate fractions. The cumulative emissions of CO2 and N2O in soil aggregate fractions in the treatments of CK and GG were 39.5–76.1% and 92.7–96.7% higher than in the GC treatment, respectively. Moreover, cumulative CO2emissions from different soil aggregate sizes in the treatments of CK and GG followed the order of small macroaggregates (2–0.25 mm) > large macroaggregates (> 2 mm) > micro aggregates (0.25–0.053 mm) > clay +silt (< 0.053 mm), whereas it decreased with aggregate sizes decreasing in the GC treatment. Additionally, soil CO2 emissions were positively correlated with SOC and TN contents. The highest cumulative N2O emission occurred in micro aggregates under the treatments of CK and GG, and N2O emissions among different aggregate sizes almost no significant difference under the GC treatment. Conclusions Conversion of natural grassland to artificial grassland changed the pattern of CO2 emissions from different soil aggregate fractions by deteriorating soil aggregate structure and altering soil SOC and TN distributions. Our findings will be helpful to develop a pragmatic management strategy for mitigating GHGs emissions from alpine grassland.
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Hamamoto, Toru, Meki Chirwa, Imasiku Nyambe y Yoshitaka Uchida. "Small-Scale Variability in the Soil Microbial Community Structure in a Semideveloped Farm in Zambia". Applied and Environmental Soil Science 2018 (2018): 1–6. http://dx.doi.org/10.1155/2018/7939123.
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The conversion of natural lands into agricultural lands can lead to changes in the soil microbial community structure which, in turn, can affect soil functions. However, few studies have examined the effect of land use changes on the soil microbial community structure in sub-Saharan Africa. Therefore, the aim of this research was to investigate the relationships among soil characteristics and microbial communities in natural and agricultural ecosystems in a semideveloped lowland farm in the central region of Zambia, within which small-scale wetlands had been partly developed as watermelon (Citrullus lanatus) and/or maize (Zea mays) farms. We sampled soils from four different land use types within this farm: “native forest,” “grassland,” “watermelon farm,” and “maize farm.” We found that the land use type had a significant effect on the soil bacterial community structure at the class level, with the class Bacilli having significantly higher relative abundances in the forest sites and Gammaproteobacteria having significantly higher relative abundances in the maize sites than in the other land use types. These findings indicate that these bacterial classes may be sensitive to changes in soil ecosystems, and so further studies are required to investigate microbial indicators for the sustainable development of wetlands in sub-Saharan Africa.
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He, Yuhong, Xulin Guo y John F. Wilmshurst. "Comparison of different methods for measuring leaf area index in a mixed grassland". Canadian Journal of Plant Science 87, n.º 4 (1 de octubre de 2007): 803–13. http://dx.doi.org/10.4141/cjps07024.
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Available LAI instruments have greatly increased our ability to estimate leaf area index (LAI) non-destructively. However, it is difficult to infer from existing studies which instrument has the advantages in measuring LAI over other instruments for grassland ecosystems. The objective of our study was to compare the LAI estimates by two instruments (AccuPAR, and LAI2000), and correlate the LAI measurements to remote sensing data for a mixed grassland. Leaf area index of four grass communities was measured by both the destructive method and instruments. Ground canopy reflectance was measured and further calculated to be LAI-related vegetation indices. Statistical analysis showed that destructively sampled LAI ranged from 0.61 to 5.7 in the study area. Both instruments underestimated LAI in comparison with the destructive method. However, the LAI2000 is better than AccuPAR for estimating LAI. Comparison of four grass communities indicated that the lower the grass LAI, the greater the underestimated percentage of LAI values collected by both instruments. The adjusted transformed soil-adjusted vegetation index (ATSAVI), was the best LAI estimator in the mixed grassland. Key words: Leaf area index, sward structure, nondestructive vegetation sampling, hyperspectral remote sensing, mixed grass prairie
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Yashiro, Erika, Eric Pinto-Figueroa, Aline Buri, Jorge E. Spangenberg, Thierry Adatte, Hélène Niculita-Hirzel, Antoine Guisan y Jan Roelof van der Meer. "Local Environmental Factors Drive Divergent Grassland Soil Bacterial Communities in the Western Swiss Alps". Applied and Environmental Microbiology 82, n.º 21 (19 de agosto de 2016): 6303–16. http://dx.doi.org/10.1128/aem.01170-16.
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ABSTRACTMountain ecosystems are characterized by a diverse range of climatic and topographic conditions over short distances and are known to shelter a high biodiversity. Despite important progress, still little is known on bacterial diversity in mountain areas. Here, we investigated soil bacterial biogeography at more than 100 sampling sites randomly stratified across a 700-km2area with 2,200-m elevation gradient in the western Swiss Alps. Bacterial grassland communities were highly diverse, with 12,741 total operational taxonomic units (OTUs) across 100 sites and an average of 2,918 OTUs per site. Bacterial community structure was correlated with local climatic, topographic, and soil physicochemical parameters with high statistical significance. We found pH (correlated with % CaO and % mineral carbon), hydrogen index (correlated with bulk gravimetric water content), and annual average number of frost days during the growing season to be among the groups of the most important environmental drivers of bacterial community structure. In contrast, bacterial community structure was only weakly stratified as a function of elevation. Contrasting patterns were discovered for individual bacterial taxa.Acidobacteriaresponded both positively and negatively to pH extremes. Various families within theBacteroidetesresponded to available phosphorus levels. Different verrucomicrobial groups responded to electrical conductivity, total organic carbon, water content, and mineral carbon contents. Alpine grassland bacterial communities are thus highly diverse, which is likely due to the large variety of different environmental conditions. These results shed new light on the biodiversity of mountain ecosystems, which were already identified as potentially fragile to anthropogenic influences and climate change.IMPORTANCEThis article addresses the question of how microbial communities in alpine regions are dependent on local climatic and soil physicochemical variables. We benefit from a unique 700-km2study region in the western Swiss Alps region, which has been exhaustively studied for macro-organismal and fungal ecology, and for topoclimatic modeling of future ecological trends, but without taking into account soil bacterial diversity. Here, we present an in-depth biogeographical characterization of the bacterial community diversity in this alpine region across 100 randomly stratified sites, using 56 environmental variables. Our exhaustive sampling ensured the detection of ecological trends with high statistical robustness. Our data both confirm previously observed general trends and show many new detailed trends for a wide range of bacterial taxonomic groups and environmental parameters.
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Yu, Y., W. Wei, L. D. Chen, F. Y. Jia, L. Yang, H. D. Zhang y T. J. Feng. "Responses of vertical soil moisture to rainfall pulses and land uses in a typical loess hilly area, China". Solid Earth 6, n.º 2 (28 de mayo de 2015): 595–608. http://dx.doi.org/10.5194/se-6-595-2015.
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Abstract. Soil moisture plays a key role in vegetation restoration and ecosystem stability in arid and semiarid regions. The response of soil moisture to rainfall pulses is an important hydrological process, which is strongly influenced by land use during the implementation of vegetation restoration. In this study, vertical soil moisture variations of woodland (Pinus tabulaeformis), native grassland (Stipa bungeana), shrubland (Hippophea rhamnoides), cropland (Triticum aestivum) and artificial grassland (Onobrychis viciaefolia) in five soil profiles were monitored in a typical loess hilly area during the 2010 growing season. The results demonstrated that rainfall pulses directly affected soil moisture variation. A multi-peak pattern of soil moisture appeared during the growing season, notably in the surface soil layer. Meanwhile, the response of each vegetation type to rainfall was inconsistent, and a time-lag effect before reaching the peak value was detected, following each heavy rainfall event. The response duration of soil moisture, however, varied markedly with the size of rainfall events. Furthermore, higher soil water content was detected in grassland and shrubland. Woodland was characterized by relatively lower soil moisture values throughout the investigation period. Our research suggests that vegetation restoration efforts should give priority to grassland and shrubland at the research site. We suggest that more studies should be focused on the characteristics of community structure and spatial vegetation distribution on soil moisture dynamics, particularly within the grass and shrub ecosystems.
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Yu, Y., W. Wei, L. D. Chen, L. Yang, F. Y. Jia y H. D. Zhang. "Responses of vertical soil moisture to rainfall pulses and land uses in a typical loess hilly area, China". Solid Earth Discussions 6, n.º 2 (18 de noviembre de 2014): 3111–39. http://dx.doi.org/10.5194/sed-6-3111-2014.
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Abstract. Soil moisture plays a key role in vegetation restoration and ecosystem stability in arid and semiarid regions. The response of soil moisture to rainfall pulses is an important hydrological process, which is strongly influenced by land use during the implementation of vegetation restoration measures. In this study, vertical soil moisture variations of woodland (Pinus tabulaeformis), native grassland (Stipa bungeana), shrubland Hippophea rhamnoides), cropland (Triticum aestivum) and artificial grassland (Onobrychis viciaefolia) in five soil profiles were monitored in a typical loess hilly area during the 2010 growing season. The results demonstrated that rainfall pulses directly affected soil moisture variation. A multi-peak pattern of soil moisture appeared during the growing season, notably in the surface soil layer. Meanwhile, the response of each vegetation type to rainfall was inconsistent, and a time-lag effect before reaching the peak value was detected, following a heavy rainfall event. The response duration of soil moisture, however, varied markedly with the size of rainfall events. Furthermore, higher soil water content was detected in grassland and shrubland. Woodland was characterized by relatively lower soil moisture values throughout the investigation period. Our research suggests that vegetation restoration efforts should give priority to grassland and shrubland at the research site. We suggest that more studies should be focused on the characteristics of community structure and spatial vegetation distribution on soil moisture dynamics, particularly within the grass and shrub ecosystems.
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Foreman, Paul W. "A framework for testing the influence of Aboriginal burning on grassy ecosystems in lowland, mesic south–eastern Australia". Australian Journal of Botany 64, n.º 8 (2016): 626. http://dx.doi.org/10.1071/bt16081.
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The complex interactions among climate, soils, fire and humans in the biogeography of natural grasslands has long been debated in Australia. On the one hand, ecological models assume the primacy of climate and soils. On the other, Aboriginal burning is hypothesised to have altered the entire continent since before the last glacial maximum. The present paper develops a framework to test for the ‘fingerprint’ of Aboriginal burning in lowland, mesic grassy ecosystems of south-eastern Australia, using ecological theory, and the ethno-historical record. It is clear that fire-stick farming was used to promote staple roots in south-eastern Australia and, in some instances, it has been shown to influence grassland–woodland boundaries. The framework comprises the following three evidence lines: (1) archival benchmarking and palaeoecology; (2) phytoecology; and (3) ethnology and archaeology. That fire-stick farming was likely instrumental in grassland formation and maintenance must be supported by evidence that shows that ‘natural’ grasslands exist in climatically–edaphically unexpected places, that fine-scale patterns and dynamics are at least partly due to fire and that the fire regime has been influenced by Aboriginal burning. Application of the framework indicated that widespread Aboriginal burning for staple foods likely extended the area of temperate grasslands and influenced their structure and function.
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Chen, Xiao, Baihui Hao, Xin Jing, Jin-Sheng He, Wenhong Ma y Biao Zhu. "Minor responses of soil microbial biomass, community structure and enzyme activities to nitrogen and phosphorus addition in three grassland ecosystems". Plant and Soil 444, n.º 1-2 (14 de agosto de 2019): 21–37. http://dx.doi.org/10.1007/s11104-019-04250-3.
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Grant, Madeleine A., Thomas J. Duff, Trent D. Penman, Bianca J. Pickering y Jane G. Cawson. "Mechanical Mastication Reduces Fuel Structure and Modelled Fire Behaviour in Australian Shrub Encroached Ecosystems". Forests 12, n.º 6 (20 de junio de 2021): 812. http://dx.doi.org/10.3390/f12060812.
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Shrub encroachment of grassland and woodland ecosystems can alter wildfire behaviour and threaten ecological values. Australian fire managers are using mechanical mastication to reduce the fire risk in encroached ecosystems but are yet to evaluate its effectiveness or ecological impact. We asked: (1) How does fuel load and structure change following mastication?; (2) Is mastication likely to affect wildfire rates of spread and flame heights?; and (3) What is the impact of mastication on flora species richness and diversity? At thirteen paired sites (masticated versus control; n = 26), located in Victoria, Australia, we measured fuel properties (structure, load and hazard) and floristic diversity (richness and Shannon’s H) in 400 mP2 plots. To quantify the effects of mastication, data were analysed using parametric and non-parametric paired sample techniques. Masticated sites were grouped into two categories, 0–2 and 3–4 years post treatment. Fire behaviour was predicted using the Dry Eucalypt Forest Fire Model. Mastication with follow-up herbicide reduced the density of taller shrubs, greater than 50 cm in height, for at least 4 years. The most recently masticated sites (0–2 years) had an almost 3-fold increase in dead fine fuel loads and an 11-fold increase in dead coarse fuel loads on the forest floor compared with the controls. Higher dead coarse fuel loads were still evident after 3–4 years. Changes to fuel properties produced a reduction in predicted flame heights from 22 m to 5–6 m under severe fire weather conditions, but no change in the predicted fire rate of spread. Reductions in flame height would be beneficial for wildfire suppression and could reduce the damage to property from wildfires. Mastication did not have a meaningful effect on native species diversity, but promoted the abundance of some exotic species.
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Labadessa, Rocco, Luigi Forte y Paola Mairota. "Exploring Life Forms for Linking Orthopteran Assemblage and Grassland Plant Community". Hacquetia 14, n.º 1 (1 de junio de 2015): 33–42. http://dx.doi.org/10.1515/hacq-2015-0012.
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AbstractOrthopterans are well known to represent the majority of insect biomass in many grassland ecosystems. However, the verification of a relationship between the traditional descriptors of orthopteran assemblage structure and plant community patterns is not straightforward. We explore the usefulness of the concept of life forms to provide insights on such ecosystem level relationship. For this purpose, thirty sample sites in semi-natural calcareous grasslands were classified according to the relative proportion of dominant herbaceous plant life forms. Orthopteran species were grouped in four categories, based on the Bei-Bienko’s life form categorization. The association among plant communities, orthopteran assemblages and environmental factors was tested by means of canonical correspondence analysis. Orthoptera groups were found to be associated with distinct plant communities, also indicating the effect of vegetation change on orthopteran assemblages. In particular, geobionta species were associated with all the most disturbed plant communities, while chortobionta and thamnobionta seemed to be dependent on better preserved grassland types. Therefore, the use of life forms could help informing on the relationships of orthopteran assemblages with grassland conservation state. Information on such community relationships at the local scale could also assist managers in the interpretation of habitat change maps in terms of biodiversity changes.
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Magandana, Thabo Patrick, Abubeker Hassen y Eyob Habte Tesfamariam. "Seasonal Herbaceous Structure and Biomass Production Response to Rainfall Reduction and Resting Period in the Semi-Arid Grassland Area of South Africa". Agronomy 10, n.º 11 (17 de noviembre de 2020): 1807. http://dx.doi.org/10.3390/agronomy10111807.
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Reduction in rainfall is amongst the major climate change manifestation phenomena, and will have a significant impact on grassland ecosystems. A split plot experimental design was used to investigate the interactive effect of rainfall reduction and resting period (RP) (70 and 90 days) on herbaceous biomass production and rainwater use efficiency in semi-arid grasslands of South Africa. Different levels of rainfall reduction (RD) were setup as main plot treatments while resting periods were set as sub-plot treatments. Four 0.5 m × 0.5 m quadrats were harvested in spring, summer and autumn of 2016/17 and 2017/18 from each sub-plot to determine herbaceous species structure, aboveground biomass production and rainwater use efficiency (RUE). Grasses were most affected by rainfall reduction than forbs at the 30% and 60% RD levels. In contrast, the forbs were more affected at 15% RD while the grasses showed resilience up to 15% reduction in rainfall. The RUE was higher at 30% RD and 70 days RP in almost all three seasons, except in spring 2016/17. Our results show that herbaceous above ground biomass showed resilience up to 15% reduction but were affected more as the rainfall reduction exceeded 30%. The future predicted reduction in rainfall may result in domination of forbs and increaser grass species in the grassland.
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Price, Jodi N., Megan K. Good, Nick L. Schultz, Lydia K. Guja y John W. Morgan. "Multivariate drivers of diversity in temperate Australian native grasslands". Australian Journal of Botany 67, n.º 5 (2019): 367. http://dx.doi.org/10.1071/bt18190.
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Disturbance has been considered essential for maintaining biodiversity in temperate grassy ecosystems in Australia. This has been particularly well demonstrated for inter-tussock plant species in C4 Themeda-dominated grasslands in mesic environments. Disturbance is also thought crucial to maintain the structure of preferred habitat for some animals. Relationships between disturbance and diversity may be contingent on ecosystem productivity, but little is known about the generality of the disturbance-promoting-diversity paradigm across the range of temperate grasslands. To date, the disturbance-promoting-diversity paradigm has taken a univariate approach to the drivers of biodiversity; rainfall is seen as a key driver of productivity, which then drives diversity, mediated by disturbance. We argue that this framework is too simplistic as biodiversity drivers are multivariate. We suggest that the accumulation of phytomass (live and dead plant material) is an important determinant of diversity in grassy ecosystems and that phytomass accumulation is governed by multiple drivers (of which disturbance is just one). For fauna, it is structure – not biomass – that determines habitat suitability, and this can be moderated by both abiotic and biotic drivers. The assumption that there is a consistent effect of disturbance on diversity through the range of temperate grassland settings in southern Australia ignores the likelihood that biodiversity also responds to other factors such as spatial heterogeneity in the environment, resource availability and climatic variation. We developed a conceptual model of the multivariate drivers of grassland diversity that explores mechanisms underpinning patterns of species richness. Despite four decades of research, it is clear that our understanding of the multivariate drivers of diversity across the range of temperate grasslands in Australia is still incomplete. Further research into the conditions under which disturbance is required to maintain biodiversity in grasslands is integral to conservation planning in these endangered systems.
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Cruz-Martínez, Karelyn, Anna Rosling, Yang Zhang, Mingzhou Song, Gary L. Andersen y Jillian F. Banfield. "Effect of Rainfall-Induced Soil Geochemistry Dynamics on Grassland Soil Microbial Communities". Applied and Environmental Microbiology 78, n.º 21 (17 de agosto de 2012): 7587–95. http://dx.doi.org/10.1128/aem.00203-12.
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ABSTRACTIn Mediterranean-type grassland ecosystems, the timing of rainfall events controls biogeochemical cycles, as well as the phenology and productivity of plants and animals. Here, we investigate the effect of short-term (days) soil environmental conditions on microbial community structure and composition during a natural wetting and drying cycle. Soil samples were collected from a meadow in Northern California at four time points after the first two rainfall events of the rainy season. We used 16S rRNA microarrays (PhyloChip) to track changes in bacterial and archaeal community composition. Microbial communities at time points 1 and 3 were significantly different than communities at time points 2 and 4. Based on ordination analysis, the available carbon, soil moisture, and temperature explained most of the variation in community structure. For the first time, a complementary and more comprehensive approach using linear regression and generalized logical networks were used to identify linear and nonlinear associations among environmental variables and with the relative abundance of subfamilies. Changes in soil moisture and available carbon were correlated with the relative abundance of many phyla. Only the phylumActinobacteriashowed a lineage-specific relationship to soil moisture but not to carbon or nitrogen. The results indicate that the use of a high taxonomic rank in correlations with nutritional indicators might obscure divergent subfamily-level responses to environmental parameters. An important implication of this research is that there is short-term variation in microbial community composition driven in part by rainfall fluctuation that may not be evident in long-term studies with coarser time resolution.
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Poeplau, Christopher, Páll Sigurðsson y Bjarni D. Sigurdsson. "Depletion of soil carbon and aggregation after strong warming of a subarctic Andosol under forest and grassland cover". SOIL 6, n.º 1 (23 de marzo de 2020): 115–29. http://dx.doi.org/10.5194/soil-6-115-2020.
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Abstract. The net loss of soil organic carbon (SOC) from terrestrial ecosystems is a likely consequence of global warming and may affect key soil functions. The strongest changes in temperature are expected to occur at high northern latitudes, with forest and tundra as prevailing land cover types. However, specific soil responses to warming in different ecosystems are currently understudied. In this study, we used a natural geothermal soil warming gradient (0–17.5 ∘C warming intensity) in an Icelandic spruce forest on Andosol to assess changes in the SOC content between 0 and 10 cm (topsoil) and between 20 and 30 cm (subsoil) after 10 years of soil warming. Five different SOC fractions were isolated, and their redistribution and the amount of stable aggregates were assessed to link SOC to changes in the soil structure. The results were compared to an adjacent, previously investigated warmed grassland. Soil warming depleted the SOC content in the forest soil by −2.7 g kg−1 ∘C−1 (−3.6 % ∘C−1) in the topsoil and −1.6 g kg−1 ∘C−1 (−4.5 % ∘C−1) in the subsoil. The distribution of SOC in different fractions was significantly altered, with particulate organic matter and SOC in sand and stable aggregates being relatively depleted and SOC attached to silt and clay being relatively enriched in warmed soils. The major reason for this shift was aggregate breakdown: the topsoil aggregate mass proportion was reduced from 60.7±2.2 % in the unwarmed reference to 28.9±4.6 % in the most warmed soil. Across both depths, the loss of one unit of SOC caused a depletion of 4.5 units of aggregated soil, which strongly affected the bulk density (an R2 value of 0.91 and p<0.001 when correlated with SOC, and an R2 value of 0.51 and p<0.001 when correlated with soil mass in stable aggregates). The proportion of water-extractable carbon increased with decreasing aggregation, which might indicate an indirect protective effect of aggregates larger than 63 µm on SOC. Topsoil changes in the total SOC content and fraction distribution were more pronounced in the forest than in the adjacent warmed grassland soils, due to higher and more labile initial SOC. However, no ecosystem effect was observed on the warming response of the subsoil SOC content and fraction distribution. Thus, whole profile differences across ecosystems might be small. Changes in the soil structure upon warming should be studied more deeply and taken into consideration when interpreting or modelling biotic responses to warming.
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Soubry, Irini, Thuy Doan, Thuan Chu y Xulin Guo. "A Systematic Review on the Integration of Remote Sensing and GIS to Forest and Grassland Ecosystem Health Attributes, Indicators, and Measures". Remote Sensing 13, n.º 16 (18 de agosto de 2021): 3262. http://dx.doi.org/10.3390/rs13163262.
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It is important to protect forest and grassland ecosystems because they are ecologically rich and provide numerous ecosystem services. Upscaling monitoring from local to global scale is imperative in reaching this goal. The SDG Agenda does not include indicators that directly quantify ecosystem health. Remote sensing and Geographic Information Systems (GIS) can bridge the gap for large-scale ecosystem health assessment. We systematically reviewed field-based and remote-based measures of ecosystem health for forests and grasslands, identified the most important ones and provided an overview on remote sensing and GIS-based measures. We included 163 English language studies within terrestrial non-tropical biomes and used a pre-defined classification system to extract ecological stressors and attributes, collected corresponding indicators, measures, and proxy values. We found that the main ecological attributes of each ecosystem contribute differently in the literature, and that almost half of the examined studies used remote sensing to estimate indicators. The major stressor for forests was “climate change”, followed by “insect infestation”; for grasslands it was “grazing”, followed by “climate change”. “Biotic interactions, composition, and structure” was the most important ecological attribute for both ecosystems. “Fire disturbance” was the second most important for forests, while for grasslands it was “soil chemistry and structure”. Less than a fifth of studies used vegetation indices; NDVI was the most common. There are monitoring inconsistencies from the broad range of indicators and measures. Therefore, we recommend a standardized field, GIS, and remote sensing-based approach to monitor ecosystem health and integrity and facilitate land managers and policy-makers.
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Liu, Huiying, Zhaorong Mi, Li Lin, Yonghui Wang, Zhenhua Zhang, Fawei Zhang, Hao Wang et al. "Shifting plant species composition in response to climate change stabilizes grassland primary production". Proceedings of the National Academy of Sciences 115, n.º 16 (16 de abril de 2018): 4051–56. http://dx.doi.org/10.1073/pnas.1700299114.
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The structure and function of alpine grassland ecosystems, including their extensive soil carbon stocks, are largely shaped by temperature. The Tibetan Plateau in particular has experienced significant warming over the past 50 y, and this warming trend is projected to intensify in the future. Such climate change will likely alter plant species composition and net primary production (NPP). Here we combined 32 y of observations and monitoring with a manipulative experiment of temperature and precipitation to explore the effects of changing climate on plant community structure and ecosystem function. First, long-term climate warming from 1983 to 2014, which occurred without systematic changes in precipitation, led to higher grass abundance and lower sedge abundance, but did not affect aboveground NPP. Second, an experimental warming experiment conducted over 4 y had no effects on any aspect of NPP, whereas drought manipulation (reducing precipitation by 50%), shifted NPP allocation belowground without affecting total NPP. Third, both experimental warming and drought treatments, supported by a meta-analysis at nine sites across the plateau, increased grass abundance at the expense of biomass of sedges and forbs. This shift in functional group composition led to deeper root systems, which may have enabled plant communities to acquire more water and thus stabilize ecosystem primary production even with a changing climate. Overall, our study demonstrates that shifting plant species composition in response to climate change may have stabilized primary production in this high-elevation ecosystem, but it also caused a shift from aboveground to belowground productivity.
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Wu, Zhang, Bao y Guo. "Run Theory and Copula-Based Drought Risk Analysis for Songnen Grassland in Northeastern China". Sustainability 11, n.º 21 (30 de octubre de 2019): 6032. http://dx.doi.org/10.3390/su11216032.
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Droughts are among the more costly natural hazards, and drought risk analysis has become urgent for the proper planning and management of water resources in grassland ecosystems. We chose Songnen grassland as a case study, used a standardized precipitation evapotranspiration index (SPEI) to model drought characteristics, employed run theory to define the drought event, and chose copula functions to construct the joint distribution for drought variables. We applied two kinds of return periods to conduct a drought risk assessment. After evaluating and comparing several distribution functions, drought severity (DS) was best described by the generalized extreme value (GEV) distribution, whereas drought duration (DD) was best fitted by gamma distribution. The root mean square error (RMSE) and Akaike Information Criterion (AIC) goodness-of-fit measures to evaluate their performance, the best-performing copula is Frank copula to model the joint dependence structure for each drought variables. The results of the secondary return periods indicate that a higher risk of droughts occurs in Keshan county, Longjiang county, Qiqiha’er city, Taonan city, and Baicheng city. Furthermore, a relatively lower risk of drought was found in Bei’an city, Mingquan county, Qinggang county, and qian’an county, and also in the Changling county and Shuangliao city. According to the calculation of the secondary return periods, which considered all possible scenarios in our study, we found that the secondary return period may be the best indicator for evaluating grassland ecosystem drought risk management.
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Bröder, Linda, Laurent Tatin, Anja Danielczak, Tobias Seibel y Axel Hochkirch. "Intensive grazing as a threat in protected areas: the need for adaptive management to protect the Critically Endangered Crau plain grasshopper Prionotropis rhodanica". Oryx 53, n.º 2 (10 de octubre de 2018): 239–46. http://dx.doi.org/10.1017/s0030605318000170.
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AbstractLivestock grazing is a key factor in many grassland ecosystems and can substantially influence the conservation of grassland species. The Crau steppe in southern France is a protected area that is traditionally grazed by sheep. The Critically Endangered Crau plain grasshopper Prionotropis rhodanica is endemic to the area and a flagship for the conservation of this unique ecosystem. Its population has declined significantly during the last 2 decades, but the reasons remain poorly understood. One potential factor is an altered habitat structure caused by changes in the grazing regime. We examined the microhabitat preferences of the species and compared the habitat structure of populated sites with those where the species is now extinct (former habitat). We found that populated sites had denser and higher vegetation, whereas former habitat had higher cover of stones and bare ground. Vegetation structure in the habitat of the smallest subpopulation was similar to areas of former habitat, suggesting a marginal habitat quality. Our results show that P. rhodanica requires 50–70% vegetation cover and suggest that grazing has contributed considerably to the population decline, but it remains unclear whether this is a direct effect of habitat degradation or an indirect effect by attracting predators associated with grazing activities. We recommend careful management of grazing to improve habitat quality, which would also benefit other invertebrates and insectivores. Continued monitoring is required to conserve habitat specialists in protected areas.
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Glass, Alex y Michael W. Eichholz. "Habitat associations of small mammal communities in a restored prairie system in southern Illinois". Journal of Mammalogy 102, n.º 3 (20 de marzo de 2021): 789–801. http://dx.doi.org/10.1093/jmammal/gyab002.
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Abstract Extensive habitat loss and degradation have transformed the grasslands of North America into one of the continent’s most vulnerable ecosystems and have greatly imperiled the plants and animals that depend on them. Small mammal communities play a pivotal role in maintaining the health and function of grasslands, and managing small mammal populations is an important, though overlooked, part of grassland restoration and management. We identified habitat variables in restored tallgrass prairie patches that were most strongly associated with variation in small mammal abundance and community composition, with the goal of aiding management efforts to manipulate small mammal populations. We found that small mammal abundance at the local vegetation scale was negatively related both to litter depth and plant diversity. At the landscape scale, small mammal abundance was positively associated with the amount of water surrounding a patch, and negatively associated with the amount of grassland surrounding a patch. Variation in small mammal community composition largely was governed by differences in habitat structure at the landscape scale, rather than differences in vegetation structure at the local scale. We suggested that managers interested in influencing small mammal abundance in grasslands employ tools such as prescribed fire to decrease litter depth if increased small mammal abundance is desired, or increase plant diversity by sowing a high diversity of seeds to depress small mammal abundance.
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Davis, Stephen K. "Area Sensitivity in Grassland Passerines: Effects of Patch Size, Patch Shape, and Vegetation Structure on Bird Abundance and Occurrence in Southern Saskatchewan". Auk 121, n.º 4 (1 de octubre de 2004): 1130–45. http://dx.doi.org/10.1093/auk/121.4.1130.
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Abstract Information on area sensitivity and effects of habitat fragmentation has come largely from forest and tallgrass-prairie habitats. Research from other ecosystems is required to determine whether the fragmentation paradigm derived from those studies is applicable to passerine communities elsewhere. I examined the effects of habitat fragmentation on abundance and occurrence of nine species of mixed-grass prairie passerines in southern Saskatchewan. I conducted 190 point-counts in 1996 and 1997 on 89 pastures ranging in size from 8 to 6,475 ha. Sprague's Pipit (Anthus spragueii), Baird's Sparrow (Ammodramus bairdii), Grasshopper Sparrow (A. savannarum), and Chestnut-collared Longspur (Calcarius ornatus) were found to be area-sensitive, in that they were more abundant or occurred more frequently, or both, in larger patches of mixed-grass prairie. However, the ratio of edge to interior habitat was a better predictor of area sensitivity than patch size in most cases. Horned Lark (Eremophila alpestris), Savannah Sparrow (Passerculus sandwichensis), Clay-colored Sparrow (Spizella pallida), Western Meadowlark (Sturnella neglecta), and Brown-headed Cowbird (Molothrus ater) were insensitive to patch size, though occurrence of Clay-colored Sparrow and Western Meadowlark tended to be greater in smaller pastures. Vegetation structure was also found to be an important predictor of grassland songbird abundance and occurrence, in that it explained additional variation not accounted for by patch size or the ratio of edge to interior habitat. Although protection of large contiguous tracts of habitat is essential to conservation of native species, small native-prairie patches with minimal edge habitat also play a vital role in conservation of grassland birds.
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Avenant, Nico. "The potential utility of rodents and other small mammals as indicators of ecosystem 'integrity' of South African grasslands". Wildlife Research 38, n.º 7 (2011): 626. http://dx.doi.org/10.1071/wr10223.
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Context The expansive grassland biome is one of the most extensively transformed in South Africa, yet no strategy for monitoring its integrity is in place. A grassland health program, incorporating different ecosystem levels, was recently initiated. The suitability of three taxonomic groups as indicators has been tested so far: vegetation (by calculating an ecological index value, El), insects (using the South African grassland scoring system, SAGraSS) and small mammals (this study). All of these methods aim to be rapid and easy to perform. Whereas SAGraSS still needs further refinement, several factors already indicate the importance of including small mammal community parameters in integrity assessments. Aims This contribution reports on more than 12 years of results from various studies on small mammals in the Free State Grasslands, with the aim of exploring the utility of small mammal survey for assessment of ecosystem integrity. Methods The hypothesis was based on the outcomes of several short-term studies conducted in the grassland biome. Combining all previous results, this paper re-evaluates the parameters of trap success, species richness, diversity, evenness and individual species as bio-indicators. Key results By combining data from many sites and years, the effect of seasonal and inter-annual variations in habitat and population parameters was diminished, and a more general picture of small mammal community structure revealed. New insights were gleaned into the status of several indicator species. By providing a summary of small mammal community parameter scores and indices, the study establishes a benchmark for future small mammal assessments and monitoring. To be effective, small mammal surveys in the grassland biome of southern Africa should be carried out in autumn and early winter. Conclusions This study suggests that small mammal species richness and diversity decline with habitat degradation; that the generalist rodent Mastomys coucha dominates community numbers at low ecological integrity; that the number of specialist species increases towards ecological climax; and that specific species act as indicators during the successional process. Implications This study should benefit the monitoring, conservation and management of grassland ecosystems, make environmental impact assessments more effective, and identify new topics for ecological research.
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Xie, Jingjie, Derong Su, Shihai Lyu, He Bu y Qiang Wo. "Dew formation characteristics of meadow plants canopy at different heights in Hulunbuir grassland, China". Hydrology Research 52, n.º 2 (5 de enero de 2021): 558–71. http://dx.doi.org/10.2166/nh.2021.168.
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Abstract A plant's foliar uptake of dew can mitigate the adverse effects caused by drought stress. However, in grassland ecosystems, it is inconclusive whether the dew condensation characteristics of plants at different heights are consistent. In this study, we wanted to know whether plant height had a significant effect on the formation of dew. In addition, we wanted to understand the difference of dew formation between C3 plant Leymus chinensis (LC) and C4 plant Cleistogenes squarrosa (CS) which have different heights and can succeed each other in the community. In nine dew nights, we measured the amount of dew formed on simulated condensation surface (different heights) and two plants at the same time. The results showed that in the height range of 5–80 cm, the dew amount increases with the canopy height, but its increase rate gradually slows down and approaches zero. The shorter CS (5–15 cm) has a similar dew amount (0.095 mm) as LC (40–70 cm) due to its compact structure of the leaves with pubescence and the more stable micro-meteorological conditions. The CS can obtain more potential dew per unit organic matter, and this may be one of the potential mechanisms for the succession from LC communities to CS communities under drought stress.
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DE CASTRO, ELMAR ANDRADE y J. BOONE KAUFFMAN. "Ecosystem structure in the Brazilian Cerrado: a vegetation gradient of aboveground biomass, root mass and consumption by fire". Journal of Tropical Ecology 14, n.º 3 (mayo de 1998): 263–83. http://dx.doi.org/10.1017/s0266467498000212.
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Conversion to permanent agriculture is rapidly occurring over vast areas of the 1.8 million km2; Brazilian Cerrado; a region that is naturally a mosaic of grasslands, savannas and evergreen tropical woodlands. Yet, few studies have quantified total biomass of plant communities in this ecosystem, particularly the belowground component; a C pool of potential global significance. Total biomass (aboveground and belowground), and the quantity of biomass consumed by fires were measured in four plant communities comprising a vegetation gradient from pure grassland (campo limpo) to a woodland with a closed canopy of tall shrubs and scattered trees (cerrado denso) near Brasilia, DF, Brazil. Total aboveground biomass (TAGB) increased along this gradient from 5.5 Mg ha-1 in campo limpo to 29.4 Mg ha-1 in cerrado denso. Vegetation structure varied among communities; trees were nonexistent in campo limpo, but were at a density of 1000 ha-1 and a biomass of 12.9 Mg ha-1 in cerrado denso. Fires consumed 92 and 84% of the TAGB in campo limpo (pure grassland) and campo sujo (savanna), respectively. In cerrado aberto and cerrado denso, trees and tall shrubs were little affected by fire. Combustion factors of the TAGB in these communities was 54 and 33%, respectively. The total biomass consumed by fire ranged from 5.0 Mg ha-1 in campo limpo to 13.5 Mg ha-1 in cerrado aberto. Compared to other widespread Brazilian ecosystems (tropical dry forest and evergreen forest), the Cerrado has a lower aboveground biomass. The TAGB of cerrado denso is > 9% of that of Amazonian tropical evergreen forest. The total quantity of biomass consumed by fire, and hence emissions to the atmosphere is lower in intact Cerrado communities compared to fires in slashed tropical forest.