Journal articles: 'Savena valley'

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Hector, Basile, Jean-Martial Cohard, Luc Séguis, Sylvie Galle, and Christophe Peugeot. "Hydrological functioning of western African inland valleys explored with a critical zone model." Hydrology and Earth System Sciences 22, no. 11 (November 14, 2018): 5867–88. http://dx.doi.org/10.5194/hess-22-5867-2018.

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Abstract. Inland valleys are seasonally waterlogged headwater wetlands, widespread across western Africa. Their role in the hydrological cycle in the humid, hard-rock-dominated Sudanian savanna is not yet well understood. Thus, while in the region recurrent floods are a major issue, and hydropower has been recognized as an important development pathway, the scientific community lacks precise knowledge of streamflow (Q) generation processes and how they could be affected by the presence of inland valleys. Furthermore, inland valleys carry an important agronomic potential, and with the strong demographic rates of the region, they are highly subject to undergoing land cover changes. We address both the questions of the hydrological functioning of inland valleys in the Sudanian savanna of western Africa and the impact of land cover changes on these systems through deterministic sensitivity experiments using a physically based critical zone model (ParFlow-CLM) applied to a virtual generic catchment which comprises an inland valley. Model forcings are based on 20 years of data from the AMMA-CATCH observation service and parameters are evaluated against multiple field data (Q, evapotranspiration – ET –, soil moisture, water table levels, and water storage) acquired on a pilot elementary catchment. The hydrological model applied to the conceptual lithological/pedological model proposed in this study reproduces the main behaviours observed, which allowed those virtual experiments to be conducted. We found that yearly water budgets were highly sensitive to the vegetation distribution: average yearly ET for a tree-covered catchment (944 mm) exceeds that of herbaceous cover (791 mm). ET differences between the two covers vary between 12 % and 24 % of the precipitation of the year for the wettest and driest years, respectively. Consequently, the tree-covered catchment produces a yearly Q amount of 28 % lower on average as compared to a herbaceous-covered catchment, ranging from 20 % for the wettest year to 47 % for a dry year. Trees also buffer interannual variability in ET by 26 % (with respect to herbaceous). On the other hand, pedological features (presence – or absence – of the low-permeability layer commonly found below inland valleys, upstream and lateral contributive areas) had limited impact on yearly water budgets but marked consequences for intraseasonal hydrological processes (sustained/non-sustained baseflow in the dry season, catchment water storage redistribution). Therefore, subsurface features and vegetation cover of inland valleys have potentially significant impacts on downstream water-dependent ecosystems and water uses as hydropower generation, and should focus our attention.

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Wang, Yang-Si-Ding, Da Yang, Huai-Dong Wu, Yun-Bing Zhang, Shu-Bin Zhang, Yong-Jiang Zhang, and Jiao-Lin Zhang. "Overlapping Water and Nutrient Use Efficiencies and Carbon Assimilation between Coexisting Simple- and Compound-Leaved Trees from a Valley Savanna." Water 12, no. 11 (October 29, 2020): 3037. http://dx.doi.org/10.3390/w12113037.

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Identifying differences in ecophysiology between simple and compound leaves can help understand the adaptive significance of the compound leaf form and its response to climate change. However, we still know surprisingly little about differences in water and nutrient use, and photosynthetic capacity between co-occurring compound-leaved and simple-leaved tree species, especially in savanna ecosystems with dry-hot climate conditions. From July to September in 2015, we investigated 16 functional traits associated with water use, nutrients, and photosynthesis of six deciduous tree species (three simple-leaved and three compound-leaved species) coexisting in a valley-savanna in Southwest China. Our major objective was to test the variation in these functional traits between these two leaf forms. Overall, overlapping leaf mass per area (LMA), photosynthesis, as well as leaf nitrogen and phosphorus concentrations were found between these coexisting valley-savanna simple- and compound-leaved tree species. We didn’t find significant differences in water and photosynthetic nitrogen or phosphorus use efficiency between simple and compound leaves. Across these simple- and compound-leaved tree species, photosynthetic phosphorus use efficiencies were positively related to LMA and negatively correlated with phosphorus concentration per mass or area. Water use efficiency (intrinsic water use efficiency or stable carbon isotopic composition) was independent of all leaf traits. Similar ecophysiology strategies among these coexisting valley-savanna simple- and compound-leaved species suggested a convergence in ecological adaptation to the hot and dry environment. The overlap in traits related to water use, carbon assimilation, and stress tolerance (e.g., LMA) also suggests a similar response of these two leaf forms to a hotter and drier future due to the climate change.

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Tao, Li, Li Jianping, and Zhao Zhiwei. "Arbuscular mycorrhizas in a valley-type savanna in southwest China." Mycorrhiza 14, no. 5 (October 28, 2003): 323–27. http://dx.doi.org/10.1007/s00572-003-0277-y.

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Saint-Martin, Arnaud. "Note sur les « penseurs » de la Silicon Valley." Savoir/Agir N°51, no. 1 (2020): 79. http://dx.doi.org/10.3917/sava.051.0079.

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Kayat, Satyawan Pudyatmoko, Muchammad Maksum, and Muhammad Ali Imron. "Potensi Konflik Penggembalaan Kuda pada Habitat Rusa Timor (Rusa timorensis Blainville 1822) di Kawasan Tanjung Torong Padang, Nusa Tenggara Timur." Jurnal Ilmu Kehutanan 11, no. 1 (January 9, 2017): 4. http://dx.doi.org/10.22146/jik.24866.

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Penggembalaan ternak telah diyakini memengaruhi keberadaan satwa liar, termasuk rusa timor (Rusa timorensis Blainville 1822) melalui kompetisi. Penelitian ini bertujuan untuk mengetahui apakah penggembalaan lepas ternak kuda yang dimiliki oleh masyarakat lokal di kawasan Tanjung Torong Padang, Nusa Tenggara Timur menjadi pesaing bagi rusa timor. Observasi lapangan dan wawancara dengan pemilik kuda dilakukan untuk menentukan distribusi kuda di habitat rusa timor. Preferensi pakan dari ternak kuda dan rusa timor dikumpulkan menggunakan identifikasi spesies dari kotoran dan dibandingkan dengan plot berukuran 1 x 1 m2 di daerah makan dari kedua hewan tersebut selama musim kering dan hujan pada 2014 dan 2015. Hasil penelitian menunjukkan tidak ada indikasi yang jelas dari persaingan antara rusa timor dan penggembalaan liar kuda di kawasan Tanjung Torong Padang. Rusa timor dan kuda tidak terjadi tumpang tindih spasial dalam distribusi mereka di lokasi tersebut. Ternak kuda menempati savana perbukitan, sedangkan rusa lebih suka menempati savana dengan pohon rengit (Albizia lebbeck (L.) Benth) dan lembah dengan vegetasi hutan tropis kering. Selain itu, rusa timor lebih menyukai makan semak dan dedaunan (browser), sementara kuda lebih menyukai rumput (grazer). Kehadiran ternak lepas kuda di kawasan Tanjung Torong Padang tidak berpengaruh negatif untuk rusa timor dan habitatnyaConflict Potential of Free-Roaming Horse Grazing on Timor Deer (Rusa timorensis Blainville 1822) Habitat in Torong Padang Cape Area, East Nusa TenggaraAbstractLivestock grazing had been believed to affect on the existence of wildlife, including the timor deer (Rusa timorensis Blainville 1822) through competition. This study aimed to determine whether the free-roaming horse grazing owned by local communities in Torong Padang Cape, East Nusa Tenggara become a competitor for timor deer. Field observations and interviews with horse owners were carried out to determine the distribution of horse in timor deer habitat. Food preference of both horse and timor deer were collected using species identification from feces and compared with 1 x 1 m2 plots at feeding areas of both animals during the dry and rainy seasons in 2014 and 2015. There is no clear indication of competition between timor deer and free-roaming horses in the Torong Padang Cape area.The deer and horse avoided overlapping spatially in their distribution in the Cape. The free-roaming horse mainly occupied hilly savanna, whereas timor deer preferred to occupy savanna with lebbek tree (Albizia lebbeck (L.) Benth) and valleys with tropical dry forest vegetation. In addition, the timor deer prefer to feed shrubs and foliage (browser), while horses prefer grass (grazer). The presence of free-roaming horse in the Torong Padang Capearea does not affect negatively for the timor deer and its habitat.

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Ebinger, John E., Loy R. Phillippe, Randy W. Nÿboer, William E. McClain, Daniel T. Busmeyer, Kenneth R. Robinson, and Geoffrey A. Levin. "Vegetation and Flora of the Sand Deposits of the Mississippi River Valley in Northwestern Illinois." Illinois Natural History Survey Bulletin 37, no. 1-6 (October 31, 2006): 191–238. http://dx.doi.org/10.21900/j.inhs.v37.122.

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This study was undertaken to determine vascular plant species composition, vegetation structure, and floristic quality of the major plant communities in the windblown sand deposits of northwestern Illinois during the growing seasons of 2002 through 2005. The major plant communities of the Ayers Sand Prairie Nature Preserve in Carroll County, Big River State Forest in Henderson County, Lost Mound Unit of the Upper Mississippi River Wildlife and Fish Refuge in Carroll and Jo Daviess counties, and the Thomson-Fulton Sand Prairie Nature Preserve located in Whiteside County were examined and the importance values determined for the plant species present. Located on broad terraces of the Mississippi River, these nature preserves and natural areas are remnants of a larger grassland/savanna/forest complex that contained extensive marsh; wet, mesic, and dry sand prairie; sand savanna; and sand forest communities. Most of the sand deposits are now cultivated and the original vegetation is found only in protected remnants, some of which are relatively large. The mature dry sand prairies were dominated by Schizachyrium scoparium; other important species were Opuntia macrorhiza, Dichanthelium villosissimum, Ambrosia psilostachya, and Tephrosia virginiana. Other assemblages of prairie and exotic species were encountered in successional sand prairie communities. Generally, the mature prairie communities in these preserves and natural areas had 35 or more species present in the study plots. Savanna and closed canopy forest communities were also examined. The dry sand savannas were dominated by Quercus velutina and Q. marilandica, dry sand forests were dominated by Q. velutina, and dry-mesic sand forests were dominated by Q. alba and Q. velutina.

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Killeen, Timothy J., and Paul N. Hinz. "Grasses of the Precambrian Shield region in eastern lowland Bolivia. I. Habitat preferences." Journal of Tropical Ecology 8, no. 4 (November 1992): 389–407. http://dx.doi.org/10.1017/s0266467400006714.

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ABSTRACTThe habitat distribution and relative abundance of 113 species of Gramineae were documented by releves in 82 stands near Conception, Santa Cruz, Bolivia. A factor analysis was used to compare the floristic similarity of stands situated in semideciduous forest, cerradao, cerrado, campo rupestre, valley-side campo, pantanal complex or on granite outcrops. Individual grass species usually had a preferred habitat and occurred with decreasing abundance in stands judged to be transitional by physiognomic, edaphic, and floristic criteria. Stands situated in cerrado vegetation were most similar to one another in grass species composition. Cerradao was transitional to semideciduous forest and cerrado but certain grasses were characteristic of this vegetation type. The floristic composition of the single campo rupestre locality was somewhat similar to cerrado; however, several of the more abundant grass species of this vegetation type did not occur in any nearby cerrado stand. Granite outcrops had a distinct grass flora and showed little similarity to other vegetation types. In savanna wetland communities, grass species distribution was influenced by water regime. Differences between stands on valley-side campo corresponded to topographic position on a gradient of increasing water surplus. Seasonally humid/dry stands on valley-side campo and pantanal complexes had a high degree of similarity. Stands lower on the catenary sequence of pantanal complexes and valley-side campos were increasingly dissimilar, a result of the different edaphic conditions of the seasonally flooded soils of pantanal complexes when compared with the permanently saturated (but never flooded) soils of valley-side campos. Pantanal complexes had the richest grass flora of all vegetation types because their microtopographic variability creates numerous micro-habitats with distinct water regimes, each supporting different grass species.

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Tang, Guoyong, and Kun Li. "Soil amelioration through afforestation and self-repair in a degraded valley-type savanna." Forest Ecology and Management 320 (May 2014): 13–20. http://dx.doi.org/10.1016/j.foreco.2014.02.018.

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Dadáková, Eva, Kristýna Brožová, Alex K. Piel, Fiona A. Stewart, David Modrý, Vladimír Celer, and Kristýna Hrazdilová. "Adenovirus infection in savanna chimpanzees (Pan troglodytes schweinfurthii) in the Issa Valley, Tanzania." Archives of Virology 163, no. 1 (October 4, 2017): 191–96. http://dx.doi.org/10.1007/s00705-017-3576-x.

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FAGBAMI, AYODELE. "Machine processing of LANDSAT data for soil survey: the Benue Valley savanna case study." International Journal of Remote Sensing 7, no. 10 (October 1986): 1237–50. http://dx.doi.org/10.1080/01431168608948928.

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BEZERRA, ALEXANDRA M. R., and JADER MARINHO-FILHO. "Bats of the Paranã River Valley, Tocantins and Goiás states, Central Brazil." Zootaxa 2725, no. 1 (January 23, 2019): 41. http://dx.doi.org/10.11646/zootaxa.2725.1.3.

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The Valley of the Paranã River is located in the states Tocantins and Goiás, Brazil. This region is inserted in the transitional area between the Cerrado, a Neotropical Savanna Hotspot, and the Amazon and Caatinga biomes. Transitional zones are alleged to be characterized by high species richness due to the overlap of species distributional ranges, and by a high level of endemism provided by the uniqueness of these regions. The aim of this study was to survey the chiropteran fauna of the Paranã River Valley, analyzing the species composition, richness and endemism, and to contribute with the increasing knowledge of the mammalian fauna of the Cerrado, since the northern portion of this biome is one of the most poorly known. We surveyed the bats using both mist net and hand capture methods, totalizing 16, 650 m2 net-hour. A total of 23 species was surveyed, being five new records for Goiás state, nine new records for Tocantins state, and 10 species considered rare or threatened. The locality Alvorada do Norte, in northeastern Goiás state, surrounded by karstic formations showed the highest number of species, highest number of new records, and of species of special interested.

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Koenig, Dolores, and Tiéman Diarra. "The Environmental Effects of Policy Change in the West African Savanna: Resettlement, Structural Adjustment and Conservation in Western Mali." Journal of Political Ecology 5, no. 1 (December 1, 1998): 23. http://dx.doi.org/10.2458/v5i1.21396.

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This article broadens analytic perspectives on the effects of government interventionsby looking at the interaction of two distinct but simultaneous policy initiatives: involuntary resettlement and structural adjustment. Case study data from the Bafing valley in Mali show that simultaneous implementation of these two initiatives reinforced the economic growth of the zone but increased negative environmental effects.Key Words: Mali, resettlement, structural adjustment, sahel, environmental degradation, economic development, river basin development, privatization, liberalization.

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JIRKŮ-POMAJBÍKOVÁ, KATEŘINA, IVAN ČEPIČKA, BARBORA KALOUSOVÁ, MILAN JIRKŮ, FIONA STEWART, BRUNO LEVECKE, DAVID MODRÝ, ALEX K. PIEL, and KLÁRA J. PETRŽELKOVÁ. "Molecular identification ofEntamoebaspecies in savanna woodland chimpanzees (Pan troglodytes schweinfurthii)." Parasitology 143, no. 6 (March 3, 2016): 741–48. http://dx.doi.org/10.1017/s0031182016000263.

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SUMMARYTo address the molecular diversity and occurrence of pathogenic species of the genusEntamoebaspp. in wild non-human primates (NHP) we conducted molecular-phylogenetic analyses onEntamoebafrom wild chimpanzees living in the Issa Valley, Tanzania. We compared the sensitivity of molecular [using a genus-specific polymerase chain reaction (PCR)] and coproscopic detection (merthiolate-iodine-formaldehyde concentration) ofEntamoebaspp. We identifiedEntamoebaspp. in 72 chimpanzee fecal samples (79%) subjected to species-specific PCRs for sixEntamoebaspecies/groups (Entamoeba histolytica, Entamoeba nuttalli, Entamoeba dispar, Entamoeba moshkovskii, Entamoeba coliandEntamoeba poleckiST2). We recorded threeEntamoebaspecies:E. coli(47%),E. dispar(16%),Entamoeba hartmanni(51%). Coproscopically, we could only distinguish the cysts of complexE. histolytica/dispar/moshkovskii/nuttalliandE. coli. Molecular prevalence of entamoebas was higher than the prevalence based on the coproscopic examination. Our molecular phylogenies showed that sequences ofE. disparandE. colifrom Issa chimpanzees are closely related to sequences from humans and other NHP from GenBank. The results showed that wild chimpanzees harbourEntamoebaspecies similar to those occurring in humans; however, no pathogenic species were detected. Molecular-phylogenetic methods are critical to improve diagnostics of entamoebas in wild NHP and for determining an accurate prevalence ofEntamoebaspecies.

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Okaeme, Augustine N., Julius S. O. Ayeni, Moses O. Oyatogun, Musa Wari, Mohammed M. Haliru, and Agboola O. Okeyoyin. "Cattle Movement and Its Ecological Implications in the Middle Niger Valley Area of Nigeria." Environmental Conservation 15, no. 4 (1988): 311–16. http://dx.doi.org/10.1017/s0376892900029805.

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Nomadic migration of cattle in the middle Niger valley is an age-old traditional method of raising cattle by pastoralism. However, this method of free-grazing of animals has been observed to affect some of the ecological balances of the savanna ecobiome. These ecological effects include denudation of the soil through excessive and repeated trampling by cattle on permanent routes, destruction of vegetational structure through uncontrolled burning and tree-lopping by pastorallists, dissemination of animal diseases due to long-distance trekking and unrestricted movement of cattle, and other social problems such as conflict with farmers when animals infiltrate into arable farmlands.With increasing use of the limited land-resources for other human activities, the need to create grazing reserves and provide infrastructures to reduce the widespread movement of cattle is recommended. This will improve the productivity of cattle and check any unfavourable ecological repercussions resulting from their unrestricted movement.

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Arnhold, Sebastian, Dennis Otieno, John Onyango, Thomas Koellner, Bernd Huwe, and John Tenhunen. "Soil properties along a gradient from hillslopes to the savanna plains in the Lambwe Valley, Kenya." Soil and Tillage Research 154 (December 2015): 75–83. http://dx.doi.org/10.1016/j.still.2015.06.021.

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McMahon, Devin E., Ian S. Pearse, Walter D. Koenig, and Eric L. Walters. "Tree community shifts and Acorn Woodpecker population increases over three decades in a Californian oak woodland." Canadian Journal of Forest Research 45, no. 8 (August 2015): 1113–20. http://dx.doi.org/10.1139/cjfr-2015-0035.

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Forest communities change in response to shifting climate, changing land use, and species introductions, as well as the interactions of established species. We surveyed the oak (Quercus L. spp.) community and Acorn Woodpecker (Melanerpes formicivorus (Swainson, 1827)) population within 230 ha of oak forest and savanna in central coastal California in 1979 and 2013 to assess demographic changes over a timescale relevant to mature oaks. Overall, percent canopy cover increased, particularly where coast live oak (Quercus agrifolia Née) and California black oak (Quercus kelloggii Newberry) were most abundant. The density of stems of Q. agrifolia increased, whereas the density of stems and basal area of valley oak (Quercus lobata Née), a species favored by Acorn Woodpeckers, decreased. The number of Acorn Woodpeckers and woodpecker territories increased over the study period, coincident with the increase in percent canopy cover; however, these increases were not related spatially. Instead, increased acorn production associated with broad-scale canopy growth likely more than compensated for the loss of Q. lobata. Our findings suggest that forests in this area are becoming denser and savanna is becoming more open, which so far has supported an increase in the Acorn Woodpecker population, despite potential habitat loss if Q. lobata continues to decline.

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Gil-Romera, Graciela, David Turton, and Miguel Sevilla-Callejo. "Landscape change in the lower Omo valley, southwestern Ethiopia: burning patterns and woody encroachment in the savanna." Journal of Eastern African Studies 5, no. 1 (February 2011): 108–28. http://dx.doi.org/10.1080/17531055.2011.544550.

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Beller, Erin E., Maggi Kelly, and Laurel G. Larsen. "From savanna to suburb: Effects of 160 years of landscape change on carbon storage in Silicon Valley, California." Landscape and Urban Planning 195 (March 2020): 103712. http://dx.doi.org/10.1016/j.landurbplan.2019.103712.

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Li, Tao, Lingfei Li, Tao Sha, Hanbo Zhang, and Zhiwei Zhao. "Molecular diversity of arbuscular mycorrhizal fungi associated with two dominant xerophytes in a valley-type savanna, southwest China." Applied Soil Ecology 44, no. 1 (January 2010): 61–66. http://dx.doi.org/10.1016/j.apsoil.2009.09.006.

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Perkins, L., G. J. Bredenkamp, and J. E. Grange. "The phytosociology of the incised river valleys and dry upland savanna of southern KwaZulu-Natal." South African Journal of Botany 65, no. 5-6 (December 1999): 321–30. http://dx.doi.org/10.1016/s0254-6299(15)31019-x.

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Lentz, David L., Carlos R. Ramírez, and Bronson W. Griscom. "Formative-Period Subsistence and Forest-Product Extraction at the Yarumela Site, Honduras." Ancient Mesoamerica 8, no. 1 (1997): 63–74. http://dx.doi.org/10.1017/s0956536100001577.

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AbstractAnalysis of paleoethnobotanical remains from the Yaramela site in central Honduras has provided insights into subsistence activities, resource-extraction preferences from surrounding ecological zones, and the transfer of plant materials through interregional exchange networks during the Formative and Late Classic periods. Remains of maize (Zea mays) and squash (Cucurbitasp.) were found as well as the wood of a number of tree species, for example, pine (Pinussp.), oak (Quercussp.), fig (Ficussp.), timber sweet (Licariasp.), andguanacaste (Enterolobium cyclocarpum). These woods were obtained from the upland pine-oak savanna, the tropical deciduous forest of the Comayagua Valley, and the circum-riverine community along the Humuya River. In an unusual discovery, the wood of cashew (Anacardiumcf.occidentale) was found in Middle Formative contexts. This, most likely an introduced domesticate from South America, appears to be the earliest record ofAnacardiumfor Honduras. Paleoethnobotanical data along with root-processing artifacts indicate a diversified subsistence pattern based on domesticates of Mesoamerican and South American origin.

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Bispo, Fábio Henrique Alves, Alexandre Christofaro Silva, Pablo Vidal Torrado, and Valdomiro Severino de Souza Junior. "Highlands of the upper Jequitinhonha valley, Brazil: II - mineralogy, micromorphology, and landscape evolution¹." Revista Brasileira de Ciência do Solo 35, no. 4 (August 2011): 1081–91. http://dx.doi.org/10.1590/s0100-06832011000400002.

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Palm swanp formations, the so-called veredas, typically occur in the Brazilian biome known as "Cerrado" (savanna-like vegetation), especially on flattened areas or tablelands (chapadas). The aim of this study was to characterize the mineralogy and micromorphology of soil materials from a representative toposequence of the watershed of the vereda Lagoa do Leandro, located in Minas Novas, state of Minas Gerais, Brazil, on plains in the region of the upper Jequitinhonha valley, emphasizing essential aspects of their genesis and landscape evolution. The toposequence is underlain by rocks of the Macaúbas group and covered with detrital and metamorphic rocks (schists of Proterozoic diamictites). The soil profiles were first pedologically described; samples of the disturbed and undisturbed soils were collected from all horizons for further micromorphological and mineralogical analyses. The mineralogical analysis was mainly based on powder X ray diffractometry (XRD) and micromorphological descriptions of thin sections under a petrographic microscope. The soils from the bottom to the top of this toposequence were classified as: Typic Albaquult (GXbd), Xanthic Haplustox, gray color, here called "Gray Haplustox" ("LAC"), Xanthic Haplustox (LA) and Typic Haplustox (LVA). The clay mineralogy of all soils was found to be dominated by kaolinite. In soil of LA and LVA, the occurrence of goethite, gibbsite, and anatase was evidenced; "LAC" also contained anatase and the GXbd, illite, anatase, and traces of vermiculite. The micromorphological analyses of the LVA, LA and "LAC" soils showed the prevalence of a microaggregate-like or granular microstructure, and aggregate porosity has a stacked/packed structure, which is typical of Oxisols. A massive structure was observed in GXbd material, with the presence of illuviation cutans of clay minerals and iron compounds. Paleogleissolos, which are strongly weathered, due to the action of the excavating fauna , and resulted in the present "LAC". The GXbd at the base of the vereda preserved the physical, mineralogical and micromorphological properties that are typical of a pedogenesis with a strong influence of long dry periods.

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Zhang, Yun‐Bing, Huai‐Dong Wu, Jie Yang, Xiao‐Yang Song, Da Yang, Fangliang He, and Jiao‐Lin Zhang. "Environmental filtering and spatial processes shape the beta diversity of liana communities in a valley savanna in southwest China." Applied Vegetation Science 23, no. 4 (September 2, 2020): 482–94. http://dx.doi.org/10.1111/avsc.12514.

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Touré, Amadou, Jonne Rodenburg, Pascal Marnotte, Ibnou Dieng, and Joël Huat. "Identifying the problem weeds of rice-based systems along the inland-valley catena in the southern Guinea Savanna, Africa." Weed Biology and Management 14, no. 2 (April 9, 2014): 121–32. http://dx.doi.org/10.1111/wbm.12040.

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Tang, Guoyong, and Kun Li. "Tree species controls on soil carbon sequestration and carbon stability following 20years of afforestation in a valley-type savanna." Forest Ecology and Management 291 (March 2013): 13–19. http://dx.doi.org/10.1016/j.foreco.2012.12.001.

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Zhang, Jiao-Lin, Jun-Jie Zhu, and Kun-Fang Cao. "Seasonal variation in photosynthesis in six woody species with different leaf phenology in a valley savanna in southwestern China." Trees 21, no. 6 (August 15, 2007): 631–43. http://dx.doi.org/10.1007/s00468-007-0156-9.

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Scofield, Douglas G., Victor Ryan Alfaro, Victoria L. Sork, Delphine Grivet, Edith Martinez, Jeannette Papp, Andrea R. Pluess, Walter D. Koenig, and Peter E. Smouse. "Foraging patterns of acorn woodpeckers (Melanerpes formicivorus) on valley oak (Quercus lobata Née) in two California oak savanna-woodlands." Oecologia 166, no. 1 (November 24, 2010): 187–96. http://dx.doi.org/10.1007/s00442-010-1828-5.

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PINTO, J. R. R., A. T. OLIVEIRA-FILHO, and J. D. V. HAY. "INFLUENCE OF SOIL AND TOPOGRAPHY ON THE COMPOSITION OF A TREE COMMUNITY IN A CENTRAL BRAZILIAN VALLEY FOREST." Edinburgh Journal of Botany 62, no. 1-2 (March 2005): 69–90. http://dx.doi.org/10.1017/s0960428606000035.

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The purpose of the present study was to investigate the correlations between environmental variables related to the substrate (soil and topography) and the distribution of tree species in a valley forest in the Chapada dos Guimarães National Park, Mato Grosso State, Brazil. The forest lies in the Cerrado Domain of Central Brazil where the dominant vegetation cover is cerrado (woody savanna). A survey of the tree community registered all live individuals with circumference at breast height (cbh)≥15cm found in eighteen 600m2 plots (total area 1.08ha). The substrate variables used in the gradient analyses were obtained from a topographic survey and from analyses of the chemical and physical properties of soil samples. A principal components analysis of soil and topography variables and a canonical correspondence analysis of the species–environment relationships produced similar results, separating both the substrate variables and the tree species abundances, mainly according to the two types of bedrock, sandstone or slate, underlying their soils, and secondly to the three topographic sectors recognized: Streamside, Mid Slope and Upper Slope. The differences in soil fertility and texture (related to the bedrocks) and the soil water regime (related to both soil texture and topography) were probably the chief factors determining the distribution of tree species in the forest.

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Ramirez-Amaya, Sebastian, Edward McLester, Fiona A. Stewart, and Alex K.Piel. "Savanna Chimpanzees (Pan troglodytes schweinfurthii) Consume and Share Blue Duiker (Philantomba monticola) Meat in the Issa Valley, Ugalla, Western Tanzania." Pan Africa News 22, no. 2 (December 2015): 17–21. http://dx.doi.org/10.5134/203111.

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Li, Qiao, B. D. Hoffmann, Zhi-xing Lu, and You-qing Chen. "Ants show that the conservation potential of afforestation efforts in Chinese valley-type savanna is dependent upon the afforestation method." Journal of Insect Conservation 21, no. 4 (June 28, 2017): 621–31. http://dx.doi.org/10.1007/s10841-017-0005-0.

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Trenc, Neven, Bojan Matoš, Josipa Velić, and Dario Perković. "APPLICATION OF GIS PROCEDURE FOR RIVER TERRACE EXTRACTION FROM A LiDAR- BASED DIGITAL ELEVATION MODEL: THE SAVA RIVER VALLEY NW OF ZAGREB, CROATIA." Rudarsko-geološko-naftni zbornik 34, no. 1 (2019): 59–70. http://dx.doi.org/10.17794/rgn.2019.1.6.

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Scatigna, André Vito, João Afonso Martins Carmo, and André Olmos Simões. "New records of Philcoxia minensis (Plantaginaceae) and Mitracarpus pusillus (Rubiaceae): conservation status assessment and notes on type specimens of two threatened species from the Espinhaço Range, Minas Gerais, Brazil." Phytotaxa 243, no. 3 (January 14, 2016): 297. http://dx.doi.org/10.11646/phytotaxa.243.3.8.

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The Espinhaço Range is a vast chain of mountains comprising ca. 120,000 km2 in the central portions of Minas Gerais and Bahia states, eastern Brazil (Ribeiro et al. 2014). Although this range represents less than 1.5% of the Brazilian territory, it harbors ca. 10% of Brazil’s angiosperm flora (Ribeiro et al. 2012). Furthermore, estimates suggest that ca. 30% of the Espinhaço Range flora is endemic (Giulietti et al. 1987). This high percentage of diversity and endemism may relate to the microhabitat heterogeneity in the “campos rupestres”, a savanna-like vegetation associated with quartzite and ironstone outcrops and white sand patches, at elevations above 900 m (Conceição & Pirani 2005, Ribeiro et al. 2014). The Diamantina Plateau, a quartzite formation of the Espinhaço Range in Minas Gerais, extends from the Araçuaí Basin, in the high Jequitinhonha Basin, to the Rio das Velhas Basin (Ribeiro et al. 2014). The Serra do Cabral, another part of the Espinhaço Range, is a rectangular mountain plateau in the same state in the São Francisco Basin, located to the west of the Diamantina Plateau and separated from it by a valley ca. 40 km wide (Hatschbach et al. 2006).

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Winkler, M. G., A. M. Swain, and J. E. Kutzbach. "Middle Holocene Dry Period in the Northern Midwestern United States: Lake Levels and Pollen Stratigraphy." Quaternary Research 25, no. 2 (March 1986): 235–50. http://dx.doi.org/10.1016/0033-5894(86)90060-8.

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Four cores from Lake Mendota in the Yahara River valley of south-central Wisconsin provide pollen, charcoal, and sediment-year. Derived estimates of stratigraphic evidence of a middle Holocene dry period in the northern Midwest. The lake level was lower between about 6500 and 3500 yr B.P. indicating that runoff from the upper Yahara River basin may have ceased during the drier seasons of the precipitation between 6500 and 3500 yr B.P. indicate a decrease of about 10% (down to about 700 mm) from the present precipitation value of 800 mm. A warming between 6500 and 3500 yr B.P. is also interpreted based on a change of vegetation from rich mesophytic forest before 6500 yr B.P. to Quercus savanna, with increased charcoal abundances after that time. After 3500 yr B.P., a closed Quercus forest and decreased charcoal suggest a cooler and wetter climate. The qualitative paleoecological interpretations, quantitative precipitation reconstructions based on pollen from the region (including the Lake Mendota data), and estimates of hydrologic budget based on lake-level changes, all show indications of a dry and warm middle Holocene. Evidence from a large regional array of sites also supports these interpretations.

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Kittelson, Pamela M., Christopher Pinahs, Joshua Dwyer, Angela Ingersoll, Elaine Mans, Jennifer Rieke, Brady Rutman, and Matthew Volenec. "Age Structure and Genetic Diversity of Four Quercus macrocarpa (Michx.) Populations in Fragmented Oak Savanna along the Central Minnesota River Valley." American Midland Naturalist 161, no. 2 (April 2009): 301–12. http://dx.doi.org/10.1674/0003-0031-161.2.301.

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Walsh, Megan K., Cathy Whitlock, and Patrick J. Bartlein. "A 14,300-year-long record of fire–vegetation–climate linkages at Battle Ground Lake, southwestern Washington." Quaternary Research 70, no. 2 (September 2008): 251–64. http://dx.doi.org/10.1016/j.yqres.2008.05.002.

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AbstractHigh-resolution macroscopic charcoal analysis was used to reconstruct a 14,300-year-long fire history record from the lower Columbia River Valley in southwestern Washington, which was compared to a previous vegetation reconstruction for the site. In the late-glacial period (ca. 14,300-13,100 cal yr BP), Pinus/Picea-dominated parkland supported little to no fire activity. From the late-glacial to the early Holocene (ca. 13,100-10,800 cal yr BP), Pseudotsuga/Abies-dominated forest featured more frequent fire episodes that burned mostly woody vegetation. In the early to middle Holocene (ca. 10,800-5200 cal yr BP), Quercus-dominated savanna was associated with frequent fire episodes of low-to-moderate severity, with an increased herbaceous (i.e., grass) charcoal content. From the middle to late Holocene (ca. 5200 cal yr BP to present), forest dominated by Pseudotsuga, Thuja-type, and Tsuga heterophylla supported less frequent, but mostly large or high-severity fire episodes. Fire episodes were least frequent, but were largest or most severe, after ca. 2500 cal yr BP. The fire history at Battle Ground Lake was apparently driven by climate, directly through the length and severity of the fire season, and indirectly through climate-driven vegetation shifts, which affected available fuel biomass.

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Skoggard, Ian, and William Kennedy. "An Interdisciplinary Approach to Agent-Based Modeling of Conflict in Eastern Africa." Practicing Anthropology 35, no. 1 (December 31, 2012): 14–18. http://dx.doi.org/10.17730/praa.35.1.26866282874725k4.

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Over the past four years, a team of computational social scientists at the Center for Social Complexity at George Mason University (GMU) in collaboration with anthropologists from the Human Relations Area Files (HRAF) at Yale University have been developing a multi-scale spatial agent-based model to better understand the environmental, social, and cultural dimensions of conflicts in the Rift Valley region of eastern Africa. The overall goal of the joint GMU-HRAF project is "to build and analyze innovative and interrelated computational models of asymmetric conflict with explicit sociocultural content that can advance understanding and improve policy analysis." 1 The anthropologists' contribution is to provide the "explicit sociocultural content" for the models. In this paper, we discuss the interdisciplinary collaboration in developing the agents for two models, a prototype model called "HerderLand" concerned with pastoral movement in a savanna environment and "RiftLand," a 1,600 sq km region in eastern Africa. The paper focuses on the give and take between the anthropologists and computational social scientists in developing the agents. The challenge for the anthropologists is how to apply their knowledge, both ethnographic and theoretical, in shaping a model that ultimately will help policymakers anticipate and manage conflict in eastern Africa.

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Zhu, Hua, Yunhong Tan, Lichun Yan, and Fangyan Liu. "Flora of the Savanna-like Vegetation in Hot Dry Valleys, Southwestern China with Implications to their Origin and Evolution." Botanical Review 86, no. 3-4 (October 6, 2020): 281–97. http://dx.doi.org/10.1007/s12229-020-09227-x.

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Barthès, B., E. Kouakoua, G. H. Sala, C. Hartmann, and B. Nyeté. "Effet à court terme de la mise en culture sur le statut organique et l’agrégation d’un sol ferrallitique argileux du Congo." Canadian Journal of Soil Science 76, no. 4 (November 1, 1996): 493–99. http://dx.doi.org/10.4141/cjss96-061.

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Cultivation of oxisols of the Niari Valley (Congo) leads to considerable decline in the soil organic carbon content and structural stability in a few years. The objective of this study was to estimate the very short-term effects of cultivation on organic status and macroaggregate (> 0.2 mm) stability of a soil which had been under savanna for 20 yr. Another objective was to identify the determinants of macroaggregate stability.On one hand, after 5 mo of manual or mechanized cultivation, stable macroaggregate content MA decreased significantly in the 0- to 10-cm layer (7% on average); soil organic carbon stock S did not (6% on average), whereas the decrease in soil organic carbon content C was significant only under mechanized cultivation (13.5% on average, vs. 7% under manual cultivation). On the other hand, the influence of cultivation on MA, S and C was not significant in the 10- to 20-cm layer (variations < 5%, on average).MA was correlated with exchangeable aluminum content (r = 0.6), though its contribution to stability was low, but was neither with "free" or "amorphous" iron and aluminum contents (r < 0.3), nor with C (r < 0.1); moreover, the influence of hot water-extractable compounds on MA was not significant. Therefore, macroaggregation did not seem to be controlled by organic matter. Key words: Macroaggregate stability, soil organic carbon, oxisol, setting into cultivation, exchangeable aluminum, hot water pretreatment

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Zhu, Jun-Jie, Jiao-Lin Zhang, Hong-Cheng Liu, and Kun-Fang Cao. "Photosynthesis, non-photochemical pathways and activities of antioxidant enzymes in a resilient evergreen oak under different climatic conditions from a valley-savanna in Southwest China." Physiologia Plantarum 135, no. 1 (January 2009): 62–72. http://dx.doi.org/10.1111/j.1399-3054.2008.01171.x.

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Soretire, Adeniyi, Olalekan Sakariyawo, Oyinkansola Yewande, John Adesodun, Aderonke Akintokun, Paul Soremi, and Sunday Aderibigbe. "Changes in microbial biomass and grain yield of rice varieties in response to the alternate wet and dry water regime in the inland valley of derived savanna." Journal of Agricultural Sciences, Belgrade 64, no. 3 (2019): 239–53. http://dx.doi.org/10.2298/jas1903239s.

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This investigation tested the hypothesis that the alternate wet and dry (AWD) water regime would increase soil microbial biomass carbon (MBC), microbial biomass nitrogen (MBN) and microbial count. Variations in MBC, MBN and grain yield could be due to varietal differences in a derived savanna. Experiments (both pot and field ones) were conducted at the Federal University of Agriculture, Abeokuta (Latitude 7? 12? to 7? 20? N and Longitude 3? 20? to 3? 28? E), Nigeria in 2015. In both trials, the treatments consisted of water regimes (continuous flooding [control] and AWD imposed on lowland rice varieties [NERICA?L-19])and Ofada [local check] at the vegetative growth stage in three cycles. The design in both trials was a completely randomised and randomised complete block design for the pot and field experiments respectively, with three replicates. In the screen house, MBC and MBN were significantly higher in AWD than in continuously flooded soil, especially at the beginning of the AWD cycles. This could have caused nutrient pulses to sustain the improved performance of lowland rice under AWD. A converse pattern was observed in the field in the third cycle. Ofada rice had a significantly higher microbial count and MBC (cycle 1) than NERICA L-19, however, a converse pattern was observed in MBC (cycles 2 and 3) and MBN (cycle 1). Composition of their rhizodeposition and timing of cycles could explain the observed varietal differences in MBC and MBN.

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Vink, Daphne N., Fiona A. Stewart, and Alex K. Piel. "Comparing Methods for Assessing Chimpanzee (Pan troglodytes schweinfurthii) Party Size: Observations, Camera Traps, and Bed Counts from a Savanna–Woodland Mosaic in the Issa Valley, Tanzania." International Journal of Primatology 41, no. 6 (February 21, 2020): 901–15. http://dx.doi.org/10.1007/s10764-020-00142-x.

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AbstractStudying animal grouping behavior is important for understanding the causes and consequences of sociality and has implications for conservation. Chimpanzee (Pan troglodytes) party size is often assessed by counting individuals or extracted indirectly from camera trap footage or the number of nests. Little is known, however, about consistency across methods for estimating party size. We collected party size data for wild chimpanzees in the Issa valley, western Tanzania, using direct observations, camera traps, and nest counts over six years (2012–2018). We compared mean monthly party size estimates calculated using each method and found that estimates derived from direct observations were weakly positively correlated with those derived from camera traps. Estimates from nest counts were not significantly correlated with either direct observations or camera traps. Overall observed party size was significantly larger than that estimated from both camera traps and nest counts. In both the dry and wet seasons, observed party size was significantly larger than camera trap party size, but not significantly larger than nest party size. Finally, overall party size and wet season party size estimated from camera traps were significantly smaller than nest party size, but this was not the case in the dry season. Our results reveal how data collection methods influence party size estimates in unhabituated chimpanzees and have implications for comparative analysis within and across primate communities. Specifically, future work must consider how estimates were calculated before we can reliably investigate environmental influences on primate behavior.

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Hartmann, Lena, Marvin Gabriel, Yuanrong Zhou, Barbara Sponholz, and Heinrich Thiemeyer. "Soil Assessment along Toposequences in Rural Northern Nigeria: A Geomedical Approach." Applied and Environmental Soil Science 2014 (2014): 1–9. http://dx.doi.org/10.1155/2014/628024.

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Case numbers of endemic Ca-deficiency rickets (CDR) have been reported to be alarmingly rising among children of subsistence farms in developing countries within the last 30 years. Fluoride toxicities in the environment are known to not be related to the disease. To investigate if, instead, CDR is caused by a nutrient deficiency in the environment, subsistence farms in an endemic CDR area near Kaduna, northern Nigeria, were investigated for bedrock, slope forms, soil types, and soil characteristics. The natural environment was investigated according to the World Reference Base, soil texture was analysed by pipette and sieving, and plant-available macronutrients were determined using barium-chloride or Ca-acetate-lactate extraction. The analyses showed that granite and slope deposits were the dominant parent materials. The typical slope forms and soil types were Lixisols and Acrisols on pediments, Fluvisols in river valleys, and Plinthosols and Acrisols on plains. Compared with West African background values, all of the soils had normal soil textures but were low in macronutrients. Comparisons to critical limits, however, showed that only the P concentrations were critically low, which are typical for savanna soils. A link between nutrient deficiency in soils and CDR in the Kaduna area was therefore considered unlikely.

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Nascimento, André Rosalvo Terra, Jeanine Maria Felfili Fagg, and Christopher William Fagg. "Canopy openness and lai estimates in two seasonally deciduous forests on limestone outcrops in central Brazil using hemispherical photographs." Revista Árvore 31, no. 1 (February 2007): 167–76. http://dx.doi.org/10.1590/s0100-67622007000100019.

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Patches of seasonally dry tropical forests occur on limestone outcrops in Central Brazil surrounded by the dominant savanna vegetation. They contain valuable timber species but are threatened by farming and mining activities. The objective of this study was to describe canopy opening and light relations in two seasonally deciduous dry forests on slopes and limestone outcrops, in the Paranã valley at the northeastern region of the Goiás state, Brazil. The studied forests were in the Fazenda Sabonete in Iaciara-Go and Fazenda Forquilha in Guarani-GO. Woody plants were sampled in 25 (20 x 20 m) plots in each forest. In the Sabonete forest 40 species, 705 ind./ha-1 with a basal area of 15.78 m²/ha-1 were found, while in Forquilha there were 55 species, 956 ind./ha-1 with a basal area of 24.76 m²/ha-1. Using hemispherical photographic techniques, 25 black and white photographs were taken at each site, during the dry season, totaling 50 photographs. These were taken at the beginning of each vegetation-sampling plot. The photographs were scanned in grey tones and saved as 'Bitmap'. The canopy opening and leaf area index (LAI) were calculated using the software Winphot. The mean canopy opening was 54.0% (±9.36) for Fazenda Sabonete and 64.6% (±11.8) in Fazenda Forquilha, with both sites presenting significant differences in the opening estimates (P < 0.05). Their floristic richness and structure also differed with the more open canopy forest, Forquilha, being richer and denser, suggesting the need for further studies on species-environment relationships in these forests.

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Abe, Susumu S., Sadahiro Yamamoto, and Toshiyuki Wakatsuki. "Physicochemical and morphological properties of termite (Macrotermes bellicosus) mounds and surrounding pedons on a toposequence of an inland valley in the southern Guinea savanna zone of Nigeria." Soil Science and Plant Nutrition 55, no. 4 (August 2009): 514–22. http://dx.doi.org/10.1111/j.1747-0765.2009.00396.x.

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Kirchholtes, Renske P. J., J. M. van Mourik, and B. R. Johnson. "Phytoliths as indicators of plant community change: A case study of the reconstruction of the historical extent of the oak savanna in the Willamette Valley Oregon, USA." CATENA 132 (September 2015): 89–96. http://dx.doi.org/10.1016/j.catena.2014.11.004.

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Schoenbrun, David. "Treating an Interdisciplinary Allergy: Methodological Approaches to Pollen Studies for the Historian of Early Africa." History in Africa 18 (1991): 323–48. http://dx.doi.org/10.2307/3172070.

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The interdisciplinary task of reconstructing early African history demands more than a passing familiarity with many fields of knowledge. Not least among these is geography, in its broader conception as the pursuit of an understanding of physiographic processes and the role(s) played by people in shaping and responding to these processes. A standard beginning in many a history book takes the reader through annual rainfall figures, topographic generalities, and, perhaps a cursory pedological overview of the region in which the people(s) under study live. Rarely are these introductory remarks integrated into the historical narrative. We are too often left to ourselves in determining the relevance, for example, of a bi-modal rainfall to the local agriculture in a subregion of open grasslands and woody savanna ecotones on black clay valley bottoms. We trust these are data relevant to our understanding of the region's agriculturalists.Many readers may know that such an area will be subject to heavy soil waterlogging during the wetter months. They may also realize that mound and ridge construction are excellent responses to the risks of root-drowning such waterlogging poses to crops such as beans, and as well, that the indigenous African grain crops Sorghum spp. and Pennisetum spp. can withstand waterlogged soils for brief periods without suffering significant loss of yield (Purseglove 1972:269-71). What is likely to be poorly understood are the forces of ecological and cultural change that have been at work in such an environment transforming the very nature of its vegetational cover and soil profile. In short, a historical perspective is necessary so that we do not run the risk of presenting Africa's ecological background in the same unchanging light as colonial ethnographers did Africa's past.

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Macola, Giacomo. "Literate Ethnohistory in Colonial Zambia: The Case of Ifikolwe Fyandi na Bantu Bandi." History in Africa 28 (2001): 187–201. http://dx.doi.org/10.2307/3172214.

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Most precolonial African states were characterized by a manifest disparity of control between center and periphery. This was certainly true of the kingdom of Kazembe, founded as a result of the collapse of the Ruund colony on the Mukulweji River towards the end of the seventeenth century and the subsequent eastward migration of an heterogeneous group of “Lundaized” titleholders. A set of flexible institutions and symbols of power helped the rulers of the emerging kingdom to maintain a degree of influence over much of southern Katanga and the westernmost reaches of the plateau to the east of the Luapula river. But in the lower Luapula valley, the heartland of the polity from about the mid-eighteenth century, eastern Lunda rule impinged more profoundly on the prerogatives of autochthonous communities and hence called for the elaboration of legitimizing devices of a special kind. In this latter context, the production and diffusion of an account of the prestigious beginnings of the Mwata Kazembes dynasty, its early dealings with the original inhabitants of the area, and later evolution served the dual purpose of fostering a dominant and discrete Lunda identity and cementing the links of subordination between foreign conquerors and local lineage or sub-clan leaders. This paper is an extended commentary on Ifikolwe Fyandi na Bantu Bandi, a mid-twentieth century offshoot of this royal tradition and a fine example of vernacular “literate ethnohistory.”Nowadays, Ifikolwe Fyandi is first and foremost the “tribal bible” that shapes the ethnic consciousness of eastern Lunda royals and aristocrats and stifles the emergence of alternative historical discourses. Ifikolwe Fyandi, however, is more than yet another manifestation of the “ubiquity” of “feedback,” for its local hegemony is mirrored by its pervasiveness within the historiography of the eastern savanna of central Africa.

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Zazzo, Antoine, Hervé Bocherens, Daniel Billiou, André Mariotti, Michel Brunet, Patrick Vignaud, Alain Beauvilain, and Hassane Taisso Mackaye. "Herbivore paleodiet and paleoenvironmental changes in Chad during the Pliocene using stable isotope ratios of tooth enamel carbonate." Paleobiology 26, no. 2 (2000): 294–309. http://dx.doi.org/10.1666/0094-8373(2000)026<0294:hpapci>2.0.co;2.

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Chad is a key region for understanding early hominid geographic expansion in relation to late Miocene and Pliocene environmental changes, owing to its location 2500 km west from the Rift Valley and to the occurrence of sites ranging in age from about 6 to 3 Ma, some of which yield fossil hominids. To reconstruct changes in herbivore paleodiet and therefore changes in the paleoenvironment, we measured the carbon and oxygen isotope composition of 80 tooth-enamel samples from three time horizons for nine families of Perissodactyla, Proboscidea, and Artiodactyla. The absence of significant alteration of in vivo isotopic signatures can be determined for carbon, thus allowing paleodietary and paleoenvironmental interpretations to be made.While the results generally confirm previous dietary hypotheses, mostly based on relative crown height, there are some notable surprises. The main discrepancies are found among low-crowned proboscideans (e.g., Anancus) and high-crowned rhinocerotids (Ceratotherium). Both species were more opportunistic feeders than it is usually believed. This result confirms that ancient feeding ecology cannot always be inferred from dental morphology or extant relatives.There is an increase in the average carbon isotope composition of tooth enamel from the oldest unit to the youngest, suggesting that the environment became richer in C4 plants with time. In turn, more C4 plants indicate an opening of the plant cover during this period. This increase in carbon isotope composition is also recorded within genera such as Nyanzachoerus, Ceratotherium, and Hexaprotodon, indicating a change from a C3-dominated to a C4-dominated diet over time. It appears that, unlike other middle Pliocene hominid sites in eastern and southern Africa, this part of Chad was characterized by very open conditions and that savanna-like grasslands were already dominant when hominids were present in the area.

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Catling, P. M., and B. Kostiuk. "Successful Re-establishment of a Native Savannah Flora and Fauna on the Site of a Former Pine Plantation at Constance Bay, Ottawa, Ontario." Canadian Field-Naturalist 124, no. 2 (April 1, 2010): 169. http://dx.doi.org/10.22621/cfn.v124i2.1056.

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To determine the extent of successful restoration of native savanna vegetation at The Sandhills, an unusual and biodiversity-rich habitat in the Ottawa Valley, we gathered information from quadrats along transects so as to compare a restored clearing with the surrounding plantation. We provide an indication of success with respect to amount of effort and provide an example of some considerations and procedures for estimating success. With a minimum effort of tree cutting and bulldozing, removal of pine duff and litter, that is estimated to have required five people over a period of less than two weeks, a hectare was successfully restored to pre-settlement savannah vegetation. Apart from a limited seeding effort following the removal of planted trees, the re-establishment of native vegetation proceeded naturally, and it was likely aided by dispersal of seed from adjacent remnant vegetation along paths and firebreaks in the vicinity. Biodiversity, based on number of species and various indices, was substantially greater in the restored clearing than in the adjacent Red Pine platation. The semi-open Jack Pine plantation accommodated species of both shaded and open habitats and diversity approached that of the clearing. However, some species such as blueberry were in poor condition in the plantation, generally not producing flowers or fruit. In addition the non-dominant vegetation was much less of the cover. In the restored area there were more regionally rare species and much greater development of flowering herbaceous species and shrubs. Orthopteran insects, a useful indicator group of plant feeding species, had much higher diversity and abundance in the restored area. Savannah and natural sand barren that have been largely destroyed by plantation forestry can be restored successfully and inexpensively, and there is thus no reason why such restorations should not include large areas and be implemented widely. Among the tools for evaluating success are historical descriptions and various measures of biodiversity and vegetation condition.

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Morais, Marcelino Santos. "Análise temporal do uso e ocupação do terreno do Parque Estadual do Biribiri e de sua Zona de Amortecimento, município de Diamantina, Minas Gerais / Temporal analysis from the land use and occupation of the Biribiri State Park and its Buffer Zone (...)." Caderno de Geografia 26, no. 46 (May 2, 2016): 362. http://dx.doi.org/10.5752/p.2318-2962.2016v26n46p362.

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O Parque Estadual do Biribiri, situado no Alto Vale do Jequitinhonha, Minas Gerais, caracteriza-se por aspectos geológicos, morfopedológicos e geoambientais que lhe confere atributos de grande potencialidade econômica, mas também de extrema fragilidade, fato que justificou a sua criação. Tal cenário gerou o o objetivo geral deste trabalho, que é analisar a evolução temporal do uso e ocupação do terreno na área do parque assim como em sua zona de amortecimento. Para fins de metodologia a pesquisa abarcou revisão bibliográfica, o reconhecimento de campo da área do parque e entorno e a realização de mapas de uso e ocupação do terreno no período entre 1991 e 2011 pelo software Multispec a partir de imagens LANDSAT 5 com composição de bandas R5G4B3. A classificação paisagística, constituída por fitofisionomias nativas predominantes na região, foi: Formação Savânica/Florestal Associada; Formação Campestre, Afloramento Rochoso. A classe caracterizada por ação antrópica foi denominada Solo Exposto. Em áreas do parque há uma tendência de estabilização da Formação Campestre e um decréscimo da classe Formação Savânica/Florestal Associada, condicionada ao tempo necessário a sua regeneração, uma vez que as imagens analisadas foram obtidas nas estações mais secas aliadas a recorrência de incêndios florestais. Evidenciou-se uma tendência de estabilização para a classe Solo Exposto. Mesmo em período anterior a criação do parque essa classe apresentou menos de 1% em sua área total. A realidade exposta pela análise temporal do uso e ocupação do terreno discorda das informações desta natureza contida no Plano de Manejo do parque o qual afirma que atividades de cunho tradicional foram fatores determinantes para a perda de qualidade ambiental na área do parque.Palavras-chave: Unidades de Conservação. Fitofisionomias do Cerrado. Dinâmica da paisagem.AbstractThe Biribiri State Park, located in the Upper Jequitinhonha Valley, Minas Gerais, is characterized by geological, morphopedological and geoenvironmental features giving it attributes of great economic potential, but also extremely fragile, a fact that justified its creation. This scenario led to aim of this study, which is to analyze the evolution of land use and occupation in the area park as well as its buffer zone. For methodology the purpose encompassed literature review, the recognition of the park and surrounding area of the field and conducting maps of land use and occupation in the period between 1991 and 2011 by Multispec software from Landsat 5 images with composition bands R5G4B3. The landscape classification, consisting of native vegetation types in the region, was: Savanna/Forestry Associate Formation; Campestre Formation, Rocky Outcrop. The class characterized by human action was called Solo Exposed. The park area, for the period 1991/1994, there is a tendency of stabilization of Campestre Formation and a decrease of Savanna/Associated Forest Formation. This reduction is due to the time required for its regeneration since the images analyzed were obtained in the drier seasons combined recurrence of forest fires. The temporal maps showed a trend of stabilization for Exposed Soil class. Even in the period before the creation of the park this category was less than 1% in your area. The reality exposed by temporal analysis of the land use and occupation disagrees with the information in question contained in Management Plan of the Biribiri Park, which states that traditional nature activities were determining factors for the loss of environmental quality in areas of the parks.Keywords: Protected Areas. Cerrado vegetation types. Landscape dynamics.

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