Journal articles: 'Biological disturbance'

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Tooker, John F., Matthew E. O'Neal, and Cesar Rodriguez-Saona. "Balancing Disturbance and Conservation in Agroecosystems to Improve Biological Control." Annual Review of Entomology 65, no. 1 (January 7, 2020): 81–100. http://dx.doi.org/10.1146/annurev-ento-011019-025143.

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Disturbances associated with agricultural intensification reduce our ability to achieve sustainable crop production. These disturbances stem from crop-management tactics and can leave crop fields more vulnerable to insect outbreaks, in part because natural-enemy communities often tend to be more susceptible to disturbance than herbivorous pests. Recent research has explored practices that conserve natural-enemy communities and reduce pest outbreaks, revealing that different components of agroecosystems can influence natural-enemy populations. In this review, we consider a range of disturbances that influence pest control provided by natural enemies and how conservation practices can mitigate or counteract disturbance. We use four case studies to illustrate how conservation and disturbance mitigation increase the potential for biological control and provide co-benefits for the broader agroecosystem. To facilitate the adoption of conservation practices that improve top-down control across significant areas of the landscape, these practices will need to provide multifunctional benefits, but should be implemented with natural enemies explicitly in mind.

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Lozon, J. D., and H. J. MacIsaac. "Biological invasions: are they dependent on disturbance?" Environmental Reviews 5, no. 2 (June 2, 1997): 131–44. http://dx.doi.org/10.1139/a97-007.

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We utilize literature surveys to examine the relationship between establishment of exotic species and human or natural disturbances of ecosystems. Of the 133 papers published in 10 ecological journals between 1993 and 1995, 63 reported on field studies involving 299 and 103 successful, nonredundant plant and animal introductions, respectively. Invasions of terrestrial ecosystems dominated (>>97%) the surveyed literature. Disturbance was associated with establishment of exotic species in 56% of these studies, though its importance differed among papers describing plants (68%) and animals (28%). Plants species (86%) were significantly more dependent on disturbance for establishment than were animals (12%). However, animals and plants that were dependent on disturbance for establishment were almost equally dependent (58 versus 68%) on it for range expansion. In a second survey, 402 plant and 103 animal taxa were identified that explicitly linked establishment of exotic species to disturbance. Human activities were attributed with establishment of species in 97 and 57% of these cases, respectively. Common mechanisms associated with establishment of exotic animals included ballast water discharge, intentional releases, and residential development. Establishment of exotic plants was associated with animal activities (e.g., grazing, seed introduction), soil disturbance, forestry, fire, agriculture, and human activities. In contrast to invasions theory, our survey indicates that the association between establishment and spread of exotic species and disturbance ought not be assumed a priori. Some animals repeatedly invade new habitats once geographic barriers are circumvented, indicating that communities may be more receptive to exotic species than previously acknowledged. By contrast, introduced plants established most often in disturbed habitats.

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Burton, Philip J., Anke Jentsch, and Lawrence R. Walker. "The Ecology of Disturbance Interactions." BioScience 70, no. 10 (September 16, 2020): 854–70. http://dx.doi.org/10.1093/biosci/biaa088.

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Abstract Global change has been accompanied by recent increases in the frequency and intensity of various ecological disturbances (e.g., fires, floods, cyclones), both natural and anthropogenic in origin. Because these disturbances often interact, their cumulative and synergistic effects can result in unforeseen consequences, such as insect outbreaks, crop failure, and progressive ecosystem degradation. We consider the roles of biological legacies, thresholds, and lag effects responsible for the distinctive impacts of interacting disturbances. We propose a hierarchical classification that distinguishes the patterns and implications associated with random co-occurrences, individual links, and multiple links among disturbances that cascade in chains or networks. Disturbance-promoting interactions apparently prevail over disturbance-inhibiting ones. Complex and exogenous disturbance cascades are less predictable than simple and endogenous links because of their dependency on adjacent or synchronous events. These distinctions help define regional disturbance regimes and can have implications for natural selection, risk assessment, and options for management intervention.

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Dornelas, Maria. "Disturbance and change in biodiversity." Philosophical Transactions of the Royal Society B: Biological Sciences 365, no. 1558 (November 27, 2010): 3719–27. http://dx.doi.org/10.1098/rstb.2010.0295.

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Understanding how disturbance affects biodiversity is important for both fundamental and applied reasons. Here, I investigate how disturbances with different ecological effects change biodiversity metrics. I define three main types of disturbance effects: D disturbance (shifts in mortality rate), B disturbance (shifts in reproductive rates) and K disturbance (shifts in carrying capacity). Numerous composite disturbances can be defined including any combination of these three types of ecological effects. The consequences of D , B and K disturbances, as well as of composite DBK disturbances are examined by comparing metrics before and after a disturbance, in disturbed and undisturbed communities. I use simulations of neutral communities and examine species richness, total abundance and species abundance distributions. The patterns of change in biodiversity metrics are consistent among different types of disturbance. K disturbance has the most severe effects, followed by D disturbance, and B disturbance has nearly negligible effects. Consequences of composite DBK disturbances are more complex than any of the three types of disturbance, with unimodal relationships along a disturbance gradient arising when D, B and K are negatively correlated. Importantly, regardless of disturbance type, community isolation enhances the negative consequences and hinders the positive effects of disturbances.

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Bell, JJ. "Sponges as agents of biological disturbance." Marine Ecology Progress Series 368 (September 25, 2008): 127–35. http://dx.doi.org/10.3354/meps07637.

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De Grandpré, Louis, Kaysandra Waldron, Mathieu Bouchard, Sylvie Gauthier, Marilou Beaudet, Jean-Claude Ruel, Christian Hébert, and Daniel Kneeshaw. "Incorporating Insect and Wind Disturbances in a Natural Disturbance-Based Management Framework for the Boreal Forest." Forests 9, no. 8 (August 2, 2018): 471. http://dx.doi.org/10.3390/f9080471.

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Natural disturbances are fundamental to forest ecosystem dynamics and have been used for two decades to improve forest management, notably in the boreal forest. Initially based on fire regimes, there is now a need to extend the concept to include other types of disturbances as they can greatly contribute to forest dynamics in some regions of the boreal zone. Here we review the main descriptors—that is, the severity, specificity, spatial and temporal descriptors and legacies, of windthrow and spruce bud worm outbreak disturbance regimes in boreal forests—in order to facilitate incorporating them into a natural disturbance-based forest management framework. We also describe the biological legacies that are generated by these disturbances. Temporal and spatial descriptors characterising both disturbance types are generally variable in time and space. This makes them difficult to reproduce in an ecosystem management framework. However, severity and specificity descriptors may provide a template upon which policies for maintaining post harvesting and salvage logging biological legacies can be based. In a context in which management mainly targets mature and old-growth stages, integrating insect and wind disturbances in a management framework is an important goal, as these disturbances contribute to creating heterogeneity in mature and old-growth forest characteristics.

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Mack, Michelle C., and Caria M. D'Antonio. "Impacts of biological invasions on disturbance regimes." Trends in Ecology & Evolution 13, no. 5 (May 1998): 195–98. http://dx.doi.org/10.1016/s0169-5347(97)01286-x.

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Rosa, Adriane R., Mercè Comes, Carla Torrent, Brisa Solè, Maria Reinares, Isabella Pachiarotti, Manel Salamero, Flávio Kapczinski, Francesc Colom, and Eduard Vieta. "Biological rhythm disturbance in remitted bipolar patients." International Journal of Bipolar Disorders 1, no. 1 (2013): 6. http://dx.doi.org/10.1186/2194-7511-1-6.

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Ferrenberg, Scott, Sasha C. Reed, and Jayne Belnap. "Climate change and physical disturbance cause similar community shifts in biological soil crusts." Proceedings of the National Academy of Sciences 112, no. 39 (September 14, 2015): 12116–21. http://dx.doi.org/10.1073/pnas.1509150112.

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Biological soil crusts (biocrusts)—communities of mosses, lichens, cyanobacteria, and heterotrophs living at the soil surface—are fundamental components of drylands worldwide, and destruction of biocrusts dramatically alters biogeochemical processes, hydrology, surface energy balance, and vegetation cover. Although there has been long-standing concern over impacts of physical disturbances on biocrusts (e.g., trampling by livestock, damage from vehicles), there is increasing concern over the potential for climate change to alter biocrust community structure. Using long-term data from the Colorado Plateau, we examined the effects of 10 y of experimental warming and altered precipitation (in full-factorial design) on biocrust communities and compared the effects of altered climate with those of long-term physical disturbance (>10 y of replicated human trampling). Surprisingly, altered climate and physical disturbance treatments had similar effects on biocrust community structure. Warming, altered precipitation frequency [an increase of small (1.2 mm) summer rainfall events], and physical disturbance from trampling all promoted early successional community states marked by dramatic declines in moss cover and increases in cyanobacteria cover, with more variable effects on lichens. Although the pace of community change varied significantly among treatments, our results suggest that multiple aspects of climate change will affect biocrusts to the same degree as physical disturbance. This is particularly disconcerting in the context of warming, as temperatures for drylands are projected to increase beyond those imposed as treatments in our study.

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Jacquet, Claire, and Florian Altermatt. "The ghost of disturbance past: long-term effects of pulse disturbances on community biomass and composition." Proceedings of the Royal Society B: Biological Sciences 287, no. 1930 (July 8, 2020): 20200678. http://dx.doi.org/10.1098/rspb.2020.0678.

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Current global change is associated with an increase in disturbance frequency and intensity, with the potential to trigger population collapses and to cause permanent transitions to new ecosystem states. However, our understanding of ecosystem responses to disturbances is still incomplete. Specifically, there is a mismatch between the diversity of disturbance regimes experienced by ecosystems and the one-dimensional description of disturbances used in most studies on ecological stability. To fill this gap, we conducted a full factorial experiment on microbial communities, where we varied the frequency and intensity of disturbances affecting species mortality, resulting in 20 different disturbance regimes. We explored the direct and long-term effects of these disturbance regimes on community biomass. While most communities were able to recover biomass and composition states similar to undisturbed controls after a halt of the disturbances, we identified some disturbance thresholds that had long-lasting legacies on communities. Using a model based on logistic growth, we identified qualitatively the sets of disturbance frequency and intensity that had equivalent long-term negative impacts on experimental communities. Our results show that an increase in disturbance intensity is a bigger threat for biodiversity and biomass recovery than the occurrence of more frequent but less intense disturbances.

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Wei, Wei, Yanjie Shao, and Min Zuo. "Active Disturbance Rejection Synchronization of Morris-Lecar Neurons." Complexity 2018 (June 5, 2018): 1–10. http://dx.doi.org/10.1155/2018/7656252.

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Synchronization of biological neurons is not only a hot topic, but also a difficult issue in the field of bioelectrical physiology. Numerous reported synchronization algorithms are designed on the basis of neural model, but they have deficiencies like relatively complex and poor robustness and are difficult to be realized. Morris-Lecar neuron is considered, and linear active disturbance rejection control (LADRC) is designed. Only one control input signal is utilized to synchronize membrane potentials of biological neurons. Meanwhile, in order to verify the robustness of synchronization, sinusoidal signal and parameter perturbations are introduced in numerical simulations. LADRC can still achieve satisfactory synchronization. Both theoretical and numerical simulation results show that LADRC is capable of estimating and cancelling disturbances and uncertainties. Neither accurate neural models nor concrete disturbance signal models are indispensable. A more practical and effective thought is provided to address the synchronization between neurons.

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Yoo, C. K., S. W. Choi, and I. Lee. "Disturbance detection and isolation in the activated sludge process." Water Science and Technology 45, no. 4-5 (February 1, 2002): 217–26. http://dx.doi.org/10.2166/wst.2002.0591.

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This paper proposes a new fault detection and isolation (FDI) method. This method monitors the distribution of process data and detects changes in this distribution, which reflect changes in the corresponding operating condition. A modified dissimilarity index and a FDI technique are defined to quantitatively evaluate the difference between data sets. This technique considers the importance of each transformed variable in the multivariate system. The FDI technique is applied to a benchmark simulation and to data from a real wastewater treatment plant. Simulation results show that it immediately detects disturbances and automatically distinguishes between serious and minor anomalies for various types of fault. The method not only detects the disturbances, but also isolates the scale of the disturbance, facilitating the interpretation of the disturbance source. The proposed monitoring technique is found to be appropriate for analyzing the biological wastewater treatment process, which is characterized by a variety of fault and disturbance sources and non-stationary characteristics.

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Antsyborov, Andrey Viktorovich, Anna Valerievna Kalinchuk, and Irina Vladimirovna Dubatova. "Sleep and Depression: What We Know and What to Learn?" Interactive science, no. 7 (53) (October 20, 2020): 33–49. http://dx.doi.org/10.21661/r-551927.

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Presently, a lot of data indicate that the disturbance of mechanisms underlying the regulation of sleep-waking cycle coincides with the mechanisms underlying the development of depression. The disturbance of circadian rhythms is one of the core factors in the genesis of the most affective disorders including depression, which indicates the role of the internal biological clock in the pathophysiology of affective disorders. The episodes of depression, mania or hypomania may result from the disturbances in endogenous biological timing. In this review, we have summarized the literature data obtained in animal models or in the patients with affective pathology, in which the connection between the function of sleep and depression was demonstrated. Specifically, we highlight the mechanisms underlying sleep dysfunction during depression (imbalance of circadian rhythms, melatonin metabolism and mechanisms of neuroinflammatory dysregulation) and provide an evidence for the link between sleep function and depression (sleep disturbances during depressive episodes, the effects of pharmacotherapy, chronotherapy, the effect of sleep deprivation, comorbidity of obstructive sleep apnea and depression).

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Bond-Lamberty, B., J. Fisk, J. A. Holm, V. Bailey, and C. M. Gough. "Moderate forest disturbance as a stringent test for gap and big-leaf models." Biogeosciences Discussions 11, no. 7 (July 21, 2014): 11217–48. http://dx.doi.org/10.5194/bgd-11-11217-2014.

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Abstract. Disturbance-induced tree mortality is a key factor regulating the carbon balance of a forest, but tree mortality and its subsequent effects are poorly represented processes in terrestrial ecosystem models. In particular, it is unclear whether models can robustly simulate moderate (non-catastrophic) disturbances, which tend to increase biological and structural complexity and are increasingly common in aging US forests. We tested whether three forest ecosystem models – Biome-BGC, a classic big-leaf model, and the ED and ZELIG gap-oriented models – could reproduce the resilience to moderate disturbance observed in an experimentally manipulated forest (the Forest Accelerated Succession Experiment in northern Michigan, USA, in which 38% of canopy dominants were stem girdled and compared to control plots). Each model was parameterized, spun up, and disturbed following similar protocols, and run for 5 years post-disturbance. The models replicated observed declines in aboveground biomass well. Biome-BGC captured the timing and rebound of observed leaf area index (LAI), while ED and ZELIG correctly estimated the magnitude of LAI decline. None of the models fully captured the observed post-disturbance C fluxes. Biome-BGC net primary production (NPP) was correctly resilient, but for the wrong reasons, while ED and ZELIG exhibited large, unobserved drops in NPP and net ecosystem production. The biological mechanisms proposed to explain the observed rapid resilience of the C cycle are typically not incorporated by these or other models. As a result we expect that most ecosystem models, developed to simulate processes following stand-replacing disturbances, will not simulate well the gradual and less extensive tree mortality characteristic of moderate disturbances.

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Berner, L. A., M. Butryn, L. Mayer, E. Stice, and M. Lowe. "Body fat deposition. Biological predictor of eating disturbance?" Appetite 57 (July 2011): S4. http://dx.doi.org/10.1016/j.appet.2011.05.123.

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Coleman, James C., Michael C. Miller, and Frank L. Mink. "Hydrologic disturbance reduces biological integrity in urban streams." Environmental Monitoring and Assessment 172, no. 1-4 (March 11, 2010): 663–87. http://dx.doi.org/10.1007/s10661-010-1363-1.

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Fenton, Nicole J. "Applied ecology in Canada’s boreal: a holistic view of the mitigation hierarchy and resilience theory." Botany 94, no. 11 (November 2016): 1009–14. http://dx.doi.org/10.1139/cjb-2016-0123.

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Canada’s boreal biome is a mosaic of forests and peatlands. These ecosystems have developed dynamically, periodically affected by disturbance events of significant spatial extent and variable severity, reducing ecosystem biomass. The same ecosystem types typically regenerate from biological legacies. However, concern is growing about the impact of these different anthropogenic disturbances, particularly compound disturbances including climate change, which open the door to shifts to alternate stable states. One strategy promoted to regulate anthropogenic disturbance is the “mitigation hierarchy” for development projects, where impacts on ecosystems are avoided, mitigated, restored, or compensated. This practical approach is not yet integrated into disturbance and resilience theory. Here, I develop an integrated view of the mitigation hierarchy, as well as resilience and disturbance theory, in a boreal context using ecosystem services to measure ecosystem state in a two-step process that first models loss of ecosystem function and then integrates the mitigation hierarchy and resilience theory. The application of this model is discussed in the context of restoration studies after different types of catastrophic anthropogenic disturbance. These studies, some of which are published in this special issue, highlight the important role of bryophytes and understory plants in setting restoration targets and developing criteria and indicators of success.

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Lear, Luke, Elze Hesse, Katriona Shea, and Angus Buckling. "Disentangling the mechanisms underpinning disturbance-mediated invasion." Proceedings of the Royal Society B: Biological Sciences 287, no. 1919 (January 29, 2020): 20192415. http://dx.doi.org/10.1098/rspb.2019.2415.

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Disturbances can play a major role in biological invasions: by destroying biomass, they alter habitat and resource abundances. Previous field studies suggest that disturbance-mediated invader success is a consequence of resource influxes, but the importance of other potential covarying causes, notably the opening up of habitats, have yet to be directly tested. Using experimental populations of the bacterium Pseudomonas fluorescens , we determined the relative importance of disturbance-mediated habitat opening and resource influxes, plus any interaction between them, for invader success of two ecologically distinct morphotypes. Resource addition increased invasibility, while habitat opening had little impact and did not interact with resource addition. Both invaders behaved similarly, despite occupying different ecological niches in the microcosms. Treatment also affected the composition of the resident population, which further affected invader success. Our results provide experimental support for the observation that resource input is a key mechanism through which disturbance increases invasibility.

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Beal-Neves, Mariana, Cleusa Vogel Ely, Marjorie Westerhofer Esteves, Betina Blochtein, Regis Alexandre Lahm, Everton L. L. Quadros, and Pedro Maria Abreu Ferreira. "The Influence of Urbanization and Fire Disturbance on Plant-floral Visitor Mutualistic Networks." Diversity 12, no. 4 (April 3, 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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Scalia, Massimo, Massimo Sperini, and Fabrizio Guidi. "The Johnson Noise in Biological Matter." Mathematical Problems in Engineering 2012 (2012): 1–11. http://dx.doi.org/10.1155/2012/582126.

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Can a very low intensity signal overcome a disturbance, the power density of which is much higher than the signal one, and yield some observable effects? The Johnson noise seems to be a disturbance so high as to cause a negative answer to that question, when one studies the effects on the cell level due to the external ELF fields generated by electric power lines (Adair, 1990, 1991). About this subject, we show that the masking effect due to the Johnson noise, known as “Adair’s constraint” and still present in the scientific debate, can be significantly weakened. The values provided by the Johnson noise formula, that is an approximate expression, can be affected by a significant deviation with respect to the correct ones, depending on the frequency and the kind of the cells, human or not human, that one is dealing with. We will give some examples. Eventually, we remark that the so-called Zhadin effect, although born and studied in a different context, could be viewed as an experimental test that gives an affirmative answer to the initial question, when the signal is an extremely weak electromagnetic field and the disturbance is a Johnson noise.

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Chen, Yiming, Wu Hong, and Yiru Fang. "Role of biological rhythm dysfunction in the development and management of bipolar disorders: a review." General Psychiatry 33, no. 1 (February 2020): e100127. http://dx.doi.org/10.1136/gpsych-2019-100127.

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Disturbance of biological rhythms contributes to the onset of bipolar disorders and is an important clinical feature of the condition. To further explore the role of biological rhythms in bipolar disorders, 95 English articles published between 1968 and 2019 were retrieved from the PubMed database and analysed. We herein review the outcomes of studies on biological rhythm disturbance in bipolar disorders, including the epidemiology, aetiology, clinical features (eg, sleep, feeding and eating disorders) and treatment of the condition evaluated by patients’ self-report and biological indicators such as melatonin. Our report supports the characterisation of biological rhythm disturbance as a significant clinical feature affecting the onset and development of bipolar disorders and reviews classical and novel treatments, such as chronotherapy, that can be applied in the clinical practice. Our analysis indicates that a more comprehensive study of the pathophysiology, clinical phenomenology and treatment of biological rhythm disturbance is required.

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Vera y Conde, C. F., and C. F. D. Rocha. "Habitat disturbance and small mammal richness and diversity in an Atlantic rainforest area in southeastern Brazil." Brazilian Journal of Biology 66, no. 4 (November 2006): 983–90. http://dx.doi.org/10.1590/s1519-69842006000600005.

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Since disturbance is an important ecological factor affecting species diversity in natural environments, the increasing human occupation rate in Brazilian Atlantic rainforest, which supports about 50% of Brazil's human population, has resulted in intense habitat degradation and fragmentation. Within this rainforest, animal and plant species have been lost at a high rate, and biological and diversity is presently vulnerable. Various animals community studies along a gradient of environmental disturbances have shown that the highest species diversities occur in habitats with intermediate levels of disturbance frequency and intensity. In the present study, which was carried out in the Atlantic forest of Ilha Grande (23° 11' S and 44° 12' W), an island located on the southern coast of Rio de Janeiro State, southeastern Brazil, we estimated species richness, diversity, and abundance of small mammals in three forest areas having different disturbance levels. This was done, in each of these areas and in an anthropic area that they surround, by establishing trails 200 m long, in which points were marked at 20 m intervals. The work involved a total effort of 4800 trap/nights. We also measured some habitat variables at each site in order to evaluated their disturbance levels. Our data showed that the two most conserved forests had the lower species richness and small mammal diversity, while in the anthropic area wild species were absent. The forest with an intermediary level of disturbance showed higher values for species richness and diversity, with the anthropic area presenting the highest disturbance level.

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Bond-Lamberty, B., J. P. Fisk, J. A. Holm, V. Bailey, G. Bohrer, and C. M. Gough. "Moderate forest disturbance as a stringent test for gap and big-leaf models." Biogeosciences 12, no. 2 (January 27, 2015): 513–26. http://dx.doi.org/10.5194/bg-12-513-2015.

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Abstract. Disturbance-induced tree mortality is a key factor regulating the carbon balance of a forest, but tree mortality and its subsequent effects are poorly represented processes in terrestrial ecosystem models. It is thus unclear whether models can robustly simulate moderate (non-catastrophic) disturbances, which tend to increase biological and structural complexity and are increasingly common in aging US forests. We tested whether three forest ecosystem models – Biome-BGC (BioGeochemical Cycles), a classic big-leaf model, and the ZELIG and ED (Ecosystem Demography) gap-oriented models – could reproduce the resilience to moderate disturbance observed in an experimentally manipulated forest (the Forest Accelerated Succession Experiment in northern Michigan, USA, in which 38% of canopy dominants were stem girdled and compared to control plots). Each model was parameterized, spun up, and disturbed following similar protocols and run for 5 years post-disturbance. The models replicated observed declines in aboveground biomass well. Biome-BGC captured the timing and rebound of observed leaf area index (LAI), while ZELIG and ED correctly estimated the magnitude of LAI decline. None of the models fully captured the observed post-disturbance C fluxes, in particular gross primary production or net primary production (NPP). Biome-BGC NPP was correctly resilient but for the wrong reasons, and could not match the absolute observational values. ZELIG and ED, in contrast, exhibited large, unobserved drops in NPP and net ecosystem production. The biological mechanisms proposed to explain the observed rapid resilience of the C cycle are typically not incorporated by these or other models. It is thus an open question whether most ecosystem models will simulate correctly the gradual and less extensive tree mortality characteristic of moderate disturbances.

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Giglio, Larriany M., Pedro V. S. Magalhães, Natalia S. Kapczinski, Júlio C. Walz, and Flávio Kapczinski. "Functional impact of biological rhythm disturbance in bipolar disorder." Journal of Psychiatric Research 44, no. 4 (March 2010): 220–23. http://dx.doi.org/10.1016/j.jpsychires.2009.08.003.

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Ledger, Mark E., Rebecca M. L. Harris, Alexander M. Milner, and Patrick D. Armitage. "Disturbance, biological legacies and community development in stream mesocosms." Oecologia 148, no. 4 (April 26, 2006): 682–91. http://dx.doi.org/10.1007/s00442-006-0412-5.

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Biswas, Shekhar R., Jingyin Xiang, and Hui Li. "Disturbance Effects on Spatial Autocorrelation in Biodiversity: An Overview and a Call for Study." Diversity 13, no. 4 (April 12, 2021): 167. http://dx.doi.org/10.3390/d13040167.

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The spatially autocorrelated patterns of biodiversity can be an important determinant of ecological processes, functions and delivery of services across spatial scales. Therefore, understanding disturbance effects on spatial autocorrelation in biodiversity is crucial for conservation and restoration planning but remains unclear. In a survey of disturbance versus spatial patterns of biodiversity literature from forests, grasslands and savannah ecosystems, we found that habitat disturbances generally reduce the spatial autocorrelation in species diversity on average by 15.5% and reduce its range (the distance up to which autocorrelation prevails) by 21.4%, in part, due to disturbance-driven changes in environmental conditions, dispersal, species interactions, or a combination of these processes. The observed effect of disturbance, however, varied markedly among the scale of disturbance (patch-scale versus habitat-scale). Surprisingly, few studies have examined disturbance effects on the spatial patterns of functional diversity, and the overall effect was non-significant. Despite major knowledge gaps in certain areas, our analysis offers a much-needed initial insights into the disturbance-driven changes in the spatial patterns of biodiversity, thereby setting the ground for informed discussion on conservation and promotion of spatial heterogeneity in managing natural systems under a changing world.

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Stonehouse, Bernard. "Biological processes in cold soils." Polar Record 35, no. 192 (January 1999): 5–10. http://dx.doi.org/10.1017/s0032247400026279.

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AbstractThis paper presents a simple model of processes by which soils develop in polar and high-altitude regions. It reviews influences of seasonal freezing, permafrost, and vegetation on soil formation; discusses recently formulated concepts of disturbance and damage; and draws attention to developments in remediation, especially possibilities for encouraging natural soil regeneration and rehabilitation processes.

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Dai, Xiaohua, Chunfa Chen, Zhongyang Li, and Xuexiong Wang. "Taxonomic, Phylogenetic, and Functional Diversity of Ferns at Three Differently Disturbed Sites in Longnan County, China." Diversity 12, no. 4 (April 1, 2020): 135. http://dx.doi.org/10.3390/d12040135.

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Human disturbances are greatly threatening to the biodiversity of vascular plants. Compared to seed plants, the diversity patterns of ferns have been poorly studied along disturbance gradients, including aspects of their taxonomic, phylogenetic, and functional diversity. Longnan County, a biodiversity hotspot in the subtropical zone in South China, was selected to obtain a more thorough picture of the fern–disturbance relationship, in particular, the taxonomic, phylogenetic, and functional diversity of ferns at different levels of disturbance. In 90 sample plots of 5 × 5 m2 along roadsides at three sites, we recorded a total of 20 families, 50 genera, and 99 species of ferns, as well as 9759 individual ferns. The sample coverage curve indicated that the sampling effort was sufficient for biodiversity analysis. In general, the taxonomic, phylogenetic, and functional diversity measured by Hill numbers of order q = 0–3 indicated that the fern diversity in Longnan County was largely influenced by the level of human disturbance, which supports the ‘increasing disturbance hypothesis’. Many functional traits of ferns at the most disturbed site were adaptive to the disturbance. There were also some indicators of fern species responding to the different disturbance levels. Hence, ferns may be considered as a good indicator group for environmental stress.

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Sadeghassadi, M., C. J. B. Macnab, and D. Westwick. "Design of a generalized predictive controller for a biological wastewater treatment plant." Water Science and Technology 73, no. 8 (January 28, 2016): 1986–2006. http://dx.doi.org/10.2166/wst.2016.050.

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This paper presents a generalized predictive control (GPC) technique to regulate the activated sludge process found in a bioreactor used in wastewater treatment. The control strategy can track dissolved oxygen setpoint changes quickly, adapting to the system uncertainties and disturbances. Tests occur on an Activated Sludge Model No. 1 benchmark of an activated sludge process. A T filter added to the GPC framework results in an effective control strategy in the presence of coloured measurement noise. This work also suggests how a constraint on the measured variable can be added as a penalty term to the GPC framework which leads to improved control of the dissolved oxygen concentration in the presence of dynamic input disturbance.

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Duan, Tingting, Jing Zhang, and Zhengjun Wang. "Responses and Indicators of Composition, Diversity, and Productivity of Plant Communities at Different Levels of Disturbance in a Wetland Ecosystem." Diversity 13, no. 6 (June 8, 2021): 252. http://dx.doi.org/10.3390/d13060252.

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Grassland tourism is a very popular leisure activity in many parts of the world. However, the presence of people in these areas causes disturbance to the local environment and grassland resources. This study analyzes the composition, diversity, and productivity under different levels of disturbance of the plant communities in the Kangxi Grassland Tourist Area and the Yeyahu Wetland Nature Reserve of Beijing, China. It aims to identify indicators of plant communities and their responses to different levels of disturbance. Our analysis shows that the plant community density and coverage have a certain compensatory increase under disturbed conditions. With the increase in disturbances, more drought-tolerant species have appeared (increased by 5.7%), some of which have become the grazing-tolerance indicator species in the trampled grazed area (TGA). For plant community productivity, biomass and height are good indicators for distinguishing different disturbances (p < 0.05). In addition, several diversity indices reveal the change of plant communities from different perspectives (three of the four indices were significant at the p < 0.05 level). For soil parameters, soil water content and organic matter concentration help to indicate different disturbance levels (the former has a 64% change). Moreover, the standard deviation of the plant community and soil parameters is also a good indicator of their spatial variability and disturbance levels, especially for the TGA. Our analysis confirms that the indicators of productivity, diversity, and soil parameters can indicate the disturbance level in each subarea from different perspectives. However, under disturbed conditions, a comprehensive analysis of these indicators is needed before we can accurately understand the state of health of the plant community.

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Edwards, Patrick M., Megan Colley, and Angie Shroufe. "Investigating Ecological Disturbance in Streams." American Biology Teacher 83, no. 4 (April 1, 2021): 254–62. http://dx.doi.org/10.1525/abt.2021.83.4.254.

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Teaching students about ecological disturbance provides them with an understanding of a critical factor that shapes the structure and function of biological communities in environmental systems. This article describes four simple experiments and related curriculum that students can use to conduct inquiry around the theme of disturbance in stream ecosystems: insect drift, colonization, life history, and the intermediate disturbance hypothesis. Over five years, our students conducted these experiments 57 times; 79% of the experiments resulted in data that supported students’ hypotheses. Our findings show that the experiments can be used as a framework for inquiry-based learning about important ecological processes such as disturbance, dispersal, colonization, and succession. These experiments meet several of the Next Generation Science Standards, are easily and ethically conducted, and require very little equipment.

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Calder, W. John, and Bryan Shuman. "Detecting past changes in vegetation resilience in the context of a changing climate." Biology Letters 15, no. 3 (March 2019): 20180768. http://dx.doi.org/10.1098/rsbl.2018.0768.

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Anthropogenic climate change is continuously altering ecological responses to disturbance and must be accounted for when examining ecological resilience. One way to measure resilience in ecological datasets is by considering the amount and duration of change from a baseline created by perturbations, such as disturbances like wildfire. Recovery occurs when ecological conditions return to equilibrium, meaning that no subsequent changes can be attributed to the effects of the disturbance, but climate change often causes the recovered state to differ from the previous baseline. The palaeoecological record provides an opportunity to examine these expectations because palaeoclimates changed continuously; few periods existed when environmental conditions were stationary. Here we demonstrate a framework for examining resilience in palaeoecological records against the backdrop of a non-stationary climate by considering resilience as two components of (i) resistance (magnitude of change) and (ii) recovery (time required to return) to predicted equilibrium values. Measuring these components of resilience in palaeoecological records requires high-resolution fossil (e.g. pollen) records, local palaeoclimate reconstructions, a model to predict ecological change in response to climate change, and disturbance records measured at the same spatial scale as the ecological (e.g. vegetation history) record. Resistance following disturbance is measured as the deviation of the fossil record from the ecological state predicted by the palaeoclimate records, and recovery time is measured as the time required for the fossil record to return to predicted values. We show that some cases may involve nearly persistent equilibrium despite large climate changes, but that others can involve a shift to a new state without any complete recovery.

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Madin, Joshua S., Michael J. O'Donnell, and Sean R. Connolly. "Climate-mediated mechanical changes to post-disturbance coral assemblages." Biology Letters 4, no. 5 (July 15, 2008): 490–93. http://dx.doi.org/10.1098/rsbl.2008.0249.

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Increasingly severe storms and weaker carbonate materials associated with more acidic oceans will increase the vulnerability of reef corals to mechanical damage. Mechanistic predictions based on measurements of colony mechanical vulnerability and future climate scenarios demonstrate dramatic shifts in assemblage structure following hydrodynamic disturbances, including switches in species' dominance on the reef and thus potential for post-disturbance recovery. Larger colonies are more resistant to factors such as disease and competition for space, and complex morphologies support more associated reef species. Future reefs are thus expected to have lower colony abundances and be dominated by small and morphologically simple, yet mechanically robust species, which will in turn support lower levels of whole-reef biodiversity than do present-day reefs.

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Kaufman, Erin A., and Sheila E. Crowell. "Biological and Behavioral Mechanisms of Identity Pathology Development: An Integrative Review." Review of General Psychology 22, no. 3 (September 2018): 245–63. http://dx.doi.org/10.1037/gpr0000138.

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Although identity disturbance is a transdiagnostic mental health problem, modern explanatory models for its emergence are limited. To date, the social, developmental, clinical, and neuropsychological literatures exploring identity processes are also largely disconnected. Existing theories have laid the foundation for understanding important components of identity pathology, yet many overlook biological, behavioral, and interactive processes by which these difficulties may emerge. In this integrative review, we explore how broad transdiagnostic vulnerabilities for psychopathology and more specific risky behavioral processes may reciprocally interact and be refined over time into an identity disturbance profile. Our primary purpose is to review behavioral and biosocial theories and derive a testable conceptual framework for how identity disturbance emerges over the course of development. We aim to describe and integrate several disparate lines of theory and research in order to illuminate potential etiological pathways to identity pathology.

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Laakso, Jouni, Veijo Kaitala, and Esa Ranta. "Non-linear biological responses to disturbance: consequences on population dynamics." Ecological Modelling 162, no. 3 (April 2003): 247–58. http://dx.doi.org/10.1016/s0304-3800(02)00385-x.

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Guo, Qinfeng. "Plant hybridization: the role of human disturbance and biological invasion." Diversity and Distributions 20, no. 11 (September 5, 2014): 1345–54. http://dx.doi.org/10.1111/ddi.12245.

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Chipps, Steven R., Daniel E. Hubbard, Kent B. Werlin, Neil J. Haugerud, Kipp A. Powell, Jo Thompson, and Tom Johnson. "Association between wetland disturbance and biological attributes in floodplain wetlands." Wetlands 26, no. 2 (June 2006): 497–508. http://dx.doi.org/10.1672/0277-5212(2006)26[497:abwdab]2.0.co;2.

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Lewy, Alfred J., Robert L. Sack, and Clifford M. Singer. "The phase angle disturbance in winter depression." Biological Psychiatry 25, no. 7 (April 1989): A83—A84. http://dx.doi.org/10.1016/0006-3223(89)91655-7.

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Hall, Alex R., Adam D. Miller, Helen C. Leggett, Stephen H. Roxburgh, Angus Buckling, and Katriona Shea. "Diversity–disturbance relationships: frequency and intensity interact." Biology Letters 8, no. 5 (May 23, 2012): 768–71. http://dx.doi.org/10.1098/rsbl.2012.0282.

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An influential ecological theory, the intermediate disturbance hypothesis (IDH), predicts that intermediate levels of disturbance will maximize species diversity. Empirical studies, however, have described a wide variety of diversity–disturbance relationships (DDRs). Using experimental populations of microbes, we show that the form of the DDR depends on an interaction between disturbance frequency and intensity. We find that diversity shows a monotonically increasing, unimodal or flat relationship with disturbance, depending on the values of the disturbance aspects considered. These results confirm recent theoretical predictions, and potentially reconcile the conflicting body of empirical evidence on DDRs.

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Subedi, Bodh Raj. "Biophysical disturbances of elephant safaris in the Royal Chitwan National Park, Nepal." Banko Janakari 9, no. 2 (July 2, 2017): 15–19. http://dx.doi.org/10.3126/banko.v9i2.17660.

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The paper explores peoples' perceptions on the biophysical impacts of elephant safaris which is a perfect way to go wildlife viewing, and is very eco-friendly. It surpasses its alternatives, especially noisy Jeep safaris. However, more people are becoming aware of the biophysical impacts of the safaris in the park. They perceived that the safaris cause negative impacts on wildlife and can destroy habitat through soil compaction and erosion, vegetation damage and disturbances. The study also estimated that the current wildlife observation distance from elephant safaris are less than fifteen metres which is too close and may be harmful to wildlife. This study provides interesting comparisons with previous studies on impacts of tourist activities on wildlife from a biological perspective in that the appropriate distances perceived by park staff to view wildlife was the only one to “fit" their findings. The distances perceived by other groups of people as appropriate would in fact, cause unacceptable levels of disturbance. It is concluded that social (human) perception of disturbance by elephant safaris may not accurately reflect the biological severity of their impacts.

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Wei, Hui, Luping Wang, Shanshan Wang, Yuxiang Jiang, and Jingmeng Li. "A Signal-Processing Neural Model Based on Biological Retina." Electronics 9, no. 1 (December 27, 2019): 35. http://dx.doi.org/10.3390/electronics9010035.

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Image signal processing has considerable value in artificial intelligence. However, due to the diverse disturbance (e.g., color, noise), the image signal processing, especially the representation of the signal, remains a big challenge. In the human visual system, it has been justified that simple cells in the primary visual cortex are obviously sensitive to vision signals with partial orientation features. In other words, the image signals are extracted and described along the pathway of visual processing. Inspired by this neural mechanism of the primary visual cortex, it is possible to build an image signal-processing model as the neural architecture. In this paper, we presented a method to process the image signal involving a multitude of disturbance. For image signals, we first extracted 4 rivalry pathways via the projection of color. Secondly, we designed an algorithm in which the computing process of the stimulus with partial orientation features can be altered into a process of analytical geometry, resulting in that the signals with orientation features can be extracted and characterized. Finally, through the integration of characterizations from the 4 different rivalry pathways, the image signals can be effectively interpreted and reconstructed. Instead of data-driven methods, the presented approach requires no prior training. With the use of geometric inferences, the method tends to be interpreted and applied in the signal processor. The extraction and integration of rivalry pathways of different colors allow the method to be effective and robust to the signals with the image noise and disturbance of colors. Experimental results showed that the approach can extract and describing the image signal with diverse disturbance. Based on the characterization of the image signal, it is possible to reconstruct signal features which can effectively represent the important information from the original image signal.

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van Praag, HM. "Serotonin-related, anxiety/aggression-driven, stressor-precipitated depression. A psycho-biological hypothesis." European Psychiatry 11, no. 2 (1996): 57–67. http://dx.doi.org/10.1016/0924-9338(96)84782-1.

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SummaryThe concept of a 5-HT related, anxiety and/or aggression-driven, stressor-precipitated depression is formulated and discussed. It comprises the following elements. The 5-HT ergic disturbances found in some depressed individuals - and of them particularly lowered CSF 5-HIAA - are linked to the anxiety- and the aggression-components of the depressive sydrome. In this type of depression - called 5-HT related depression - dysregulation of anxiety and/or aggression are primordial and mood lowering is a derivative phenomenon. In other words this is a group of anxiety/aggression-driven depressions. The 5-HT ergic impairment in certain types of depression is a trait-phenomenon, ie, persists during remission. This disturbance makes the individual susceptable for perturbation of anxiety- and aggression-regulation. Anxiety and (overt or suppressed) anger, are core constituents of the stress-syndrome. Thus, the 5-HT ergic disturbance will induce a heightened sensitivity for stressful events, ie, the latter will induce more readily than normal, stress phenomena , among which anxiety and anger. The latter psychological features induce lowering of mood and thus “drive” the patient into a fullblown depression. Furthermore it is predicted that anxiolytics and serenics (ie, anti-aggressive drugs) that act via normalisation of 5-HT ergic circuits, will exert a antidepressant effect in 5-HT related depression, in addition to their therapeutic actions in anxiety disorders and states of increased aggressiveness, respectively. The exact nature of the 5-HT ergic impairment in 5-HT related depression has yet to be elucidated.

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Sniders, A., A. Laizans, and T. Komass. "Invariant Control of the Technological Plants to Compensate an Impact of Main Disturbances Preemptively." Latvian Journal of Physics and Technical Sciences 53, no. 3 (June 1, 2016): 34–44. http://dx.doi.org/10.1515/lpts-2016-0019.

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Abstract The paper considers a survey of the research procedures and results due to invariant control method application perspective for operation quality advancement in several technological plants (wastewater biological treatment tanks and water steam production boilers), which operate under influence of organised and random disturbances. A specified subject of research is the simulation model of the multi-link invariant control system for steam pressure stabilisation in a steam boiler by preemptive compensation of steam load and feed water flow impact on output parameter (steam pressure), developed in MATLAB/SIMULINK. Simulation block-diagram of the steam boiler invariant control system, containing closed loop PID control circuit and open loop DPC circuit, has been composed on the basis of the designed mathematical model of the system components, disturbance compensation algorithms, and operational equation of the invariant control system. Comparative response of the steam boiler, operating under influence of fluctuating disturbances, with conventional PID control and using PID-DPC control with disturbance compensation controller DPC, has been investigated. Simulation results of invariant PID – DPC control system show that output parameter of the steam boiler - pressure remains practically constant under fluctuating disturbances due to a high-speed response of DPC controller.

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Harding, Harry R., Timothy A. C. Gordon, Rachel E. Hsuan, Alex C. E. Mackaness, Andrew N. Radford, and Stephen D. Simpson. "Fish in habitats with higher motorboat disturbance show reduced sensitivity to motorboat noise." Biology Letters 14, no. 10 (October 2018): 20180441. http://dx.doi.org/10.1098/rsbl.2018.0441.

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Anthropogenic noise can negatively impact many taxa worldwide. It is possible that in noisy, high-disturbance environments, the range and severity of impacts could diminish over time, but the influence of previous disturbance remains untested in natural conditions. This study demonstrates the effects of motorboat noise on the physiology of an endemic cichlid fish in Lake Malawi. Exposure to motorboats (driven 20–100 m from fish) and loudspeaker playback of motorboat noise both elevated the oxygen-consumption rate at a single lower-disturbance site, characterized by low historic and current motorboat activity. Repeating this assay at further lower-disturbance sites revealed a consistent effect of elevated oxygen consumption in response to motorboat disturbance. However, when similar trials were repeated at four higher-disturbance sites, no effect of motorboat exposure was detected. These results demonstrate that disturbance history can affect local population responses to noise. Action regarding noise pollution should consider the past, as well as the present, when planning for the future.

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Dawson, Geraldine, David Hessl, and Karin Frey. "Social influences on early developing biological and behavioral systems related to risk for affective disorder." Development and Psychopathology 6, no. 4 (1994): 759–79. http://dx.doi.org/10.1017/s0954579400004776.

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AbstractDramatic changes take place in the neural physiology and emotional behavior of the human infant during the first 2 years of life. Evidence suggests that certain variations in the infant's early social environment, such as disturbances in mother-infant interaction that are associated with maternal depression, influence the development of biological systems related to the expression and regulation of emotion, particularly those systems involved in frontal lobe, autonomic, and adrenocortical functioning. In this essay, we provide an overview of the links between maternal depression and disruptions in early social and emotional development, and we highlight parallels between disturbances in biological systems found in depressed adults and those found in infants of mothers experiencing depression. We then discuss the possibility of sensitive periods for the enduring influences of maternal depression on the emotional development of these children and for increased risk for affective disorder. Finally, we point to directions for further research on the nature of the intergenerational transmission of emotional disturbance.

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Woods, Lauren M., Elizabeth G. Biro, Muxi Yang, and Kevin G. Smith. "Does regional diversity recover after disturbance? A field experiment in constructed ponds." PeerJ 4 (October 18, 2016): e2455. http://dx.doi.org/10.7717/peerj.2455.

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The effects of disturbance on local species diversity have been well documented, but less recognized is the possibility that disturbances can alter diversity at regional spatial scales. Since regional diversity can dictate which species are available for recolonization of degraded sites, the loss of diversity at regional scales may impede the recovery of biodiversity following a disturbance. To examine this we used a chemical disturbance of rotenone, a piscicide commonly used for fish removal in aquatic habitats, on small fishless freshwater ponds. We focused on the non-target effects of rotenone on aquatic invertebrates with the goal of assessing biodiversity loss and recovery at both local (within-pond) and regional (across ponds) spatial scales. We found that rotenone caused significant, large, but short-term losses of species at both local and regional spatial scales. Using a null model of random extinction, we determined that species were selectively removed from communities relative to what would be expected if species loss occurred randomly. Despite this selective loss of biodiversity, species diversity at both local and regional spatial scales recovered to reference levels one year after the addition of rotenone. The rapid recovery of local and regional diversity in this study was surprising considering the large loss of regional species diversity, however many aquatic invertebrates disperse readily or have resting stages that may persist through disturbances. We emphasize the importance of considering spatial scale when quantifying the impacts of a disturbance on an ecosystem, as well as considering how regional species loss can influence recovery from disturbance.

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Walsh, B. Timothy, Ellen Zimmerli, Michael J. Devlin, Janet Guss, and Harry R. Kissileff. "A disturbance of gastric function in bulimia nervosa." Biological Psychiatry 54, no. 9 (November 2003): 929–33. http://dx.doi.org/10.1016/s0006-3223(03)00176-8.

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Tollefson, Gary D., and Yili Lu. "Comorbid mood disturbance in schizophrenia." Schizophrenia Research 24, no. 1-2 (January 1997): 192. http://dx.doi.org/10.1016/s0920-9964(97)82550-9.

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Zhang, Xianliang, and Xuanrui Huang. "Human disturbance caused stronger influences on global vegetation change than climate change." PeerJ 7 (September 25, 2019): e7763. http://dx.doi.org/10.7717/peerj.7763.

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Global vegetation distribution has been influenced by human disturbance and climate change. The past vegetation changes were studied in numerous studies while few studies had addressed the relative contributions of human disturbance and climate change on vegetation change. To separate the influences of human disturbance and climate change on the vegetation changes, we compared the existing vegetation which indicates the vegetation distribution under human influences with the potential vegetation which reflects the vegetation distribution without human influences. The results showed that climate-induced vegetation changes only occurred in a few grid cells from the period 1982–1996 to the period 1997–2013. Human-induced vegetation changes occurred worldwide, except in the polar and desert regions. About 3% of total vegetation distribution was transformed by human activities from the period 1982–1996 to the period 1997–2013. Human disturbances caused stronger damage to global vegetation change than climate change. Our results indicated that the regions where vegetation experienced both human disturbance and climate change are eco-fragile regions.

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Temmink, H., B. Petersen, S. Isaacs, and M. Henze. "Recovery of biological phosphorus removal after periods of low organic loading." Water Science and Technology 34, no. 1-2 (July 1, 1996): 1–8. http://dx.doi.org/10.2166/wst.1996.0349.

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Activated sludge plants for enhanced biological phosphorus removal (EBPR) are often disturbed by short periods of low organic loading. Depending on the exact nature of the disturbance this may result in a partial or complete depletion of the internal PHB stores. PHB and phosphate measurements in a pilot-scale EBPR process show that recovery from such disturbances is slow and temporarily results in high phosphate concentrations. The measurements strongly suggest that the main reason for this slow recovery is a dependency of P-uptake on a slowly rising level of PHB. In a number of batch experiments this dependency of P-uptake on PHB was clearly shown. Also, based on the results of these batch experiments, a more detailed analysis was made of the effect of organic loading and aeration time on EBPR recovery. It is concluded that to obtain EBPR recovery, the aeration time should be carefully adjusted to the organic loading, particularly if the organic loading is low.

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Journal articles on the topic 'Biological disturbance'

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