Ecological Regime Research Articles

Shifting Pacific storm tracks as stressors to ecosystems of western North America.

Much of the precipitation delivered to western North America arrives during the cool season via midlatitude Pacific storm tracks, which may experience future shifts in response to climate change. Here, we assess the sensitivity of the hydroclimate and ecosystems of western North America to the latitudinal position of cool-season Pacific storm tracks. We calculated correlations between storm track variability and three hydroclimatic variables: gridded cool-season standardized precipitation-evapotranspiration index, April snow water equivalent, and water year streamflow from a network of USGS stream gauges. To assess how historical storm track variability affected ecosystem processes, we derived forest growth estimates from a large network of tree-ring widths and land surface phenology and wildfire estimates from remote sensing. From 1980 to 2014, cool-season storm tracks entered western North America between approximately 41°N and 53°N. Cool-season moisture supply and snowpack responded strongly to storm track position, with positive correlations to storm track latitude in eastern Alaska and northwestern Canada but negative correlations in the northwestern U.S. Ecosystems of the western United States were greener and more productive following winters with south-shifted storm tracks, while Canadian ecosystems were greener in years when the cool-season storm track was shifted to the north. On average, larger areas of the northwestern United States were burned by moderate to high severity wildfires when storm tracks were displaced north, and the average burn area per fire also tended to be higher in years with north-shifted storm tracks. These results suggest that projected shifts of Pacific storm tracks over the 21st century would likely alter hydroclimatic and ecological regimes in western North America, particularly in the northwestern United States, where moisture supply and ecosystem processes are highly sensitive to the position of cool-season storm tracks.

Sixteen lessons from a 40-year quest to understand the mysterious life of the grey triggerfish

Abstract Fish stock assessments based solely on energy flow through the ecosystem are not good predictors of population dynamics. To accurately forecast the response of populations within one or more ecological regimes, consideration must be given to non-trophic mechanisms allowing interactions inside the system, and fish behaviour in response to changes in their habitats. The example of the grey triggerfish (Balistes capriscus) in West Africa shows that fisheries biology is unable to model satisfactorily the life of a fish population. The Ecosystem Approach to Fisheries improves the models but does not overcome this fundamental limitation. Data from direct observations of fish biology and behaviour must be added to the catch and environmental data to help to design energetic-cybernetic models in order to anticipate non-linear and chaotic dynamics. This requires adding data collected by fishers (e.g. underwater acoustics) to scientific data bases, conceiving environmental indicators (e.g. habitat), and using scenarios to anticipate the reactions of populations to regime shifts. It also requires a good understanding of the population structures and strategies. We developed the concept of “pelagic metapopulation” which, through comparative analysis with the jack mackerel (Trachurus murphyi), allowed us to propose a hypothesis explaining the history of the grey triggerfish population.

Land-use regime shift triggered the recent degradation of alpine pastures in Nyanpo Yutse of the eastern Qinghai-Tibetan Plateau

The eastern Qinghai-Tibetan Plateau is a cultural landscape where traditional pastoralism substantially shaped the present mosaic structure of the alpine grasslands. During the past two decades, however, severe grassland degradations of this region has been considered as the major ecological concern. In this study we took an interdisciplinary approach to investigate the impact of the historical land-use regimes to the observed degradation, by conducting an in-depth case study in a local pastoral village in the Nyanpo Yutse region. Firstly, we mapped historical land-use intensities (LUIs) of the study area at land-use transition time points of 1970s, 1984, 1994 and 2015 with oral history and participatory GIS (PGIS) approaches. Secondly, we conducted Landsat and Moderate Resolution Imaging Spectroradiometer (MODIS) time series analysis to detect the temporal and spatial patterns of the degradation. Thirdly, we discussed the causal relations between the land-use and land-cover changes. Livestock and pasture privatization from 1984 to 1994 created the land-use regime shift which resulted in a marked increase in LUIs and decreased pastoral mobility. The LUI increase in this transition period fostered the establishment of short-grass vegetation which facilitated the spreading of plateau pikas. The installment of iron fences as private pasture borders from 2004 to 2007 eventually started the onset of degradation. Our case study illustrates that the past land-use regime shift triggered the recent ecological regime shift in Nyanpo Yutse. Severe grassland degradation occurred with a time lag during which cumulative LUIs surpassed the vulnerability threshold of the biophysical system.

Discourses, Narratives and Purposeful Action – Unraveling the Social–Ecological Complexity within the Brahmaputra Basin in India

AbstractIssues of disaster and governance in the Brahmaputra Basin of India have been part of different debates within the epistemic boundaries. This study of a social–ecological regime shift, from a prosperous paddy cultivated region within the north bank of the Upper Brahmaputra Valley to a sediment deposited wasteland, unravels the complex relations between narratives of a problem and purposeful action. It is found that policy and practice solutions may not always be grounded in the problem situation but can be shaped by wider discourses and social learning. The study illustrates the continuation of engineering solutions without deeper understanding of their influence on social dynamics, the typification of community behaviour with an ignorance of cultural legacies, and a lack of prioritization of adaptation needs in the novel social–ecological conditions of the region. The conceptual frameworks of flood control debates contribute to distinct discourses influencing policy and praxis, while the discontented riparian community is motivated, by actors influenced by identity and space politics, towards political autonomy. Such influences of opposing discourses may reinforce the narrative of a trust gap between the Indian polity and its Northeast Region. The study further identifies a latent capacity for flexibility in the community, which requires more attention from policy and praxis to explore management solutions in such a complex social–ecological system. The paper argues for science, policy and practice engagements in such contexts and the use of transdisciplinary heuristics for their design to facilitate shared understanding. Copyright © 2017 John Wiley & Sons, Ltd and ERP Environment

Is Climate Change Shifting the Poleward Limit of Mangroves?

Ecological (poleward) regime shifts are a predicted response to climate change and have been well documented in terrestrial and more recently ocean species. Coastal zones are amongst the most susceptible ecosystems to the impacts of climate change, yet studies particularly focused on mangroves are lacking. Recent studies have highlighted the critical ecosystem services mangroves provide, yet there is a lack of data on temporal global population response. This study tests the notion that mangroves are migrating poleward at their biogeographical limits across the globe in line with climate change. A coupled systematic approach utilising literature and land surface and air temperature data was used to determine and validate the global poleward extent of the mangrove population. Our findings indicate that whilst temperature (land and air) have both increased across the analysed time periods, the data we located showed that mangroves were not consistently extending their latitudinal range across the globe. Mangroves, unlike other marine and terrestrial taxa, do not appear to be experiencing a poleward range expansion despite warming occurring at the present distributional limits. Understanding failure for mangroves to realise the global expansion facilitated by climate warming may require a focus on local constraints, including local anthropogenic pressures and impacts, oceanographic, hydrological, and topographical conditions.

Humans as Agents in the Termination of the African Humid Period

There is great uncertainty over the timing and magnitude of the termination of the African Humid Period (AHP). Spanning from the early to middle Holocene, the AHP was a period of enhanced moisture over most of northern and eastern Africa. However, beginning 8000 years ago the moisture balance shifted due to changing orbital precession and vegetation feedbacks. Some proxy records indicate a rapid transition from wet to dry conditions, while others indicate a more gradual changeover. Heretofore, humans have been viewed as passive agents in the termination of the AHP, responding to changing climatic conditions by adopting animal husbandry and spreading an agricultural lifestyle across the African continent. This paper explores scenarios whereby humans could be viewed as active agents in landscape denudation. During the period when agriculture was adopted in northern Africa, the regions where it was occurring were at the precipice of ecological regime shifts. Pastoralism, in particular, is argued to enhance devegetation and regime shifts in unbalanced ecosystems. Threshold crossing events were documented in the historical records of New Zealand and western North America due to the introduction of livestock. In looking at temporally correlated archaeological and paleoenvironmental records of northern Africa, similar landscape dynamics from the historical precedents are observed: reduction in net primary productivity, homogenization of the flora, transformation of the landscape into a shrub-dominated biozone and increasing xerophylic vegetation overall. Although human agents are not seen as the only forces inducing regime change during the termination of the AHP, their potential role in inducing large-scale landscape change must be properly contextualized against other global occurrences of neolithization.

Drivers and predictions of coral reef carbonate budget trajectories.

Climate change is one of the greatest threats to the long-term maintenance of coral-dominated tropical ecosystems, and has received considerable attention over the past two decades. Coral bleaching and associated mortality events, which are predicted to become more frequent and intense, can alter the balance of different elements that are responsible for coral reef growth and maintenance. The geomorphic impacts of coral mass mortality have received relatively little attention, particularly questions concerning temporal recovery of reef carbonate production and the factors that promote resilience of reef growth potential. Here, we track the biological carbonate budgets of inner Seychelles reefs from 1994 to 2014, spanning the 1998 global bleaching event when these reefs lost more than 90% of coral cover. All 21 reefs had positive budgets in 1994, but in 2005 budgets were predominantly negative. By 2014, carbonate budgets on seven reefs were comparable with 1994, but on all reefs where an ecological regime shift to macroalgal dominance occurred, budgets remained negative through 2014. Reefs with higher massive coral cover, lower macroalgae cover and lower excavating parrotfish biomass in 1994 were more likely to have positive budgets post-bleaching. If mortality of corals from the 2016 bleaching event is as severe as that of 1998, our predictions based on past trends would suggest that six of eight reefs with positive budgets in 2014 would still have positive budgets by 2030. Our results highlight that reef accretion and framework maintenance cannot be assumed from the ecological state alone, and that managers should focus on conserving aspects of coral reefs that support resilient carbonate budgets.

Evidence for early sedentism at Körtik Tepe, southeastern Turkey, during the Younger Dryas

Location: Körtik Tepe, Province Diyarbakır, Southeastern Turkey, at the confluence of the River Tigris and the Batman Creek. Period: Younger Dryas to Early Holocene (10400-9200 BCE) Focus: Archaeological evidence for permanent occupation of the site; conditions favouring early sedentism at the intersection of two ecological regimes: the riverine environments and the steppe/tree-steppe mountain ranges of the hinterland; ecological and socio-economic impact of sedentism and of climatic changes from the Younger Dryas to the Early Holocene; interpretation of burial customs comparing evidence of daily practices and emerging differentiation in burial rituals. Methods: Archaeobotany, stable isotope analyses, modelling of radiocarbon sequences; holistic approach

Morphological divergences and ecological correlates among wild populations of zebrafish (Danio rerio)

Studies on morphological differences among populations from different ecological regions help towards understanding diversification of traits and is a fundamental step in adaptive radiation and ultimately, speciation. This study investigates the occurrence of variations in morphological traits among wild populations of zebrafish (Danio rerio) from India that inhabit a variety of habitat and ecological regimes. Geometric morphometric methods and traditional morphometric analysis were used to quantify the extent of differences in morphological traits between four populations of wild D. rerio from still-water (stagnant) (Kalibazaar, in West Bengal) and slow -medium flowing (Asan, Kaushalya and Seripetkalwa in Uttarakhand, Haryana and Andhra Pradesh respectively) habitats within India. Multivariate analyses showed significant effect of populations on morphology, post-hoc paired comparisons between populations show differences in body size as well as shape across these populations. Relative warps analyses on the landmarks selected for body shape showed higher loadings for caudal peduncle, head and eye regions. Population-wise scatterplots along relative warp1 (RW1)- relative warp4 (RW4) axes revealed Asan population cluster expands beyond the other population clusters along the RW1- RW2 axes, while the Kalibazaar cluster spreads out from the others along the RW3-RW4 axes. Multiple regression models to predict relation between shape and ecological attributes indicate the strongest role of dissolved oxygen, stream velocity and abundance of predators in explaining variations in morphology across these populations. This is significant as a first study utilising the tools of morphometric analyses in Danio rerio and indicating the role of multiple (biotic and abiotic) selective forces in shaping phenotypic variations in morphology.

ФИТОИНДИКАЦИОННОЕ ОЦЕНИВАНИЕ КАТЕНЫ СООБЩЕСТВ ПОЧВЕННОЙ МЕЗОФАУНЫ И ИХ ЭКОМОРФИЧЕСКАЯ ОРГАНИЗАЦИЯ

The approaches to the use of catena method of studying the diversity of soil animal communities’ arena landscape of the Dnieper River Valley (within the natural reserve “Dnieper-Orelsky” using phytoindication estimation have been developed in the present article. Soil animals ecomorphes have been verified on the basis of main trends variability of environmental conditions which evaluated by means of phytoindication approaches. Monitoring polygon situated in the north-eastern part of the natural reserve "Dnieper-Orelsky". The width of the polygon is 3260 m, height – 2850 m, its total area is 930 hectares. Inside the polygon we selected some five plots: on the slope of the sand dunes at the border the sandy steppe and Acer tataricum shrub; on the slope of the Northern exposure of the Orlova valley in Acer tataricum oak forest with Dáctylis glomeráta; in terrace near the flood plain on the border with the lower part of the slope, in elm-black poplar forest with Glechóma hederácea; in the waterlogged tributary of river Protoch on the border of the marsh and forest ecosystems; in river Protoch in grass community, in a gradient from the marsh community to steppe meadows. Each plot was represented by 105 squares of size 3×3 m. Squares arranged in 7 contiguous rows of 15 squares in each. Plot size was 21×45 m. Big side plot was located along the visually discernible gradient terrain topography and vegetation cover. In each square we made a description of the vegetation with the assessment of the projective cover with a lag of 10%. In the center of each square we sampled soil of 0.25×0.25 m from which the soil macroinvertebrates have been extracted by hand sorting. The ordination of mesopedobionts communities has been applied to multidimensional scaling procedure based on metrics of Bray-Curtis with provisional data on transformation according to Hellinger. The phytoindication estimation of the environmental regimes have been found to be statistically significant predictors of multidimensional scales that obtained after ordination of mesopedobionts communities. Dimension 1 can be explained by edaphotop nutrient status, dimension 2 can be explained by edaphotop humidity, dimension 3 may be explained by soil aeration, dimension 4 may be explained by quantity of carbonates in soil. Dimensions 5 and 6 have a complex factor nature which is difficult to interpret meaningfully. Environmental assessment regimes using phyto-indicative scales enabled set the value of soil carbonate content and aeration in structuring of soil animals communities. The obtained result makes reasonable provision of new ecomorphes of soil animals such as aèromorph and carbonatomorph. Aèromorphes are ecological group that combines soil animals, preferring similar condition of soil aeration, among which are highlighted in aerophyles, sub-aerophyles, hemiaerofobes and subaerofobes. Carbonatomorphes are ecological group that combines soil animals, preferring similar condition of carbonates content in soil, among which are highlighted in carbonatofobes, akarbonatophyles, hemicarbonatophyles, carbonatophyles and hyper-carbonatophyles. Classic catena approach for biogeocenotic and landscape diversity investigation have been supplemented by the assessment of the ecological regimes through phytoindication and ecomorphic analysis of vegetation. Ordinates of ecological regimes are the gradients of variation of soil animal communities. Information and valuable markers of vegetation (phytoindication scale and ecomorphes) can be used as training variables to assess the indicator properties of soil animal communities. Ecomorphes of soil animals reflect the main aspects of the structural organization of their communities and may serve as valuable indicators of the properties and behaviors of soil as environment of living organisms.

Hypoxic areas, density-dependence and food limitation drive the body condition of a heavily exploited marine fish predator.

Investigating the factors regulating fish condition is crucial in ecology and the management of exploited fish populations. The body condition of cod (Gadus morhua) in the Baltic Sea has dramatically decreased during the past two decades, with large implications for the fishery relying on this resource. Here, we statistically investigated the potential drivers of the Baltic cod condition during the past 40 years using newly compiled fishery-independent biological data and hydrological observations. We evidenced a combination of different factors operating before and after the ecological regime shift that occurred in the Baltic Sea in the early 1990s. The changes in cod condition related to feeding opportunities, driven either by density-dependence or food limitation, along the whole period investigated and to the fivefold increase in the extent of hypoxic areas in the most recent 20 years. Hypoxic areas can act on cod condition through different mechanisms related directly to species physiology, or indirectly to behaviour and trophic interactions. Our analyses found statistical evidence for an effect of the hypoxia-induced habitat compression on cod condition possibly operating via crowding and density-dependent processes. These results furnish novel insights into the population dynamics of Baltic Sea cod that can aid the management of this currently threatened population.

Anthropogenic changes in environmental conditions of phytocoenoses of medium sized-sized Ukrainian river valleys (based on the example of the River Tyasmyn – a tributary of the Dnieper)

The problem of anthropogenic degradation of rivers is usually marked by its multi-sectoral and often international character as well by the large number of sources of environmental threat. Therefore, its solution requires a systematic approach based on transparent and coordinated interagency and international cooperation. The River Dnieper inUkrainehas undergone a remarkable transformation as a result of the construction of a cascade of reservoirs. Anthropogenic damage to the plants and soil that cover its basin have caused damage to the functioning of ecological regimes of theDnieper’s tributaries. Small and medium-sized rivers are dying. In this article, attention is paid to a typical middle-sized (164 km) river of theDnieperBasin, the Tyasmyn. Its middle and lower parts are located in the overtransformed Irdyn-Tyasmyn valley. During the last glaciation it formed the central part of the right arm of the ancientDnieper. Regulation of the Tyasmyn runoff, pollution, the creation of theKremenchugreservoir on theDnieper, grazing and recreational load have led to the threat of the river degrading. Therefore, the aim of this article is to characterize the structure of the herbaceous vegetation in the central and lower parts of the Tyasmyn valley and assess the level of its dependence on anthropogenic changes in the conditions of the ecotypes. The methods used are: retrospective and system analysis, comparative ecology (ecological profile or transect), botanic methods, phytoindication, the mapping method and mathematical statistics. The features of changes in environmental conditions of ecotypes of the river valley have been shown through systematic, biomorphological, ecomorphic structure of the herbaceous cover, the ratio of ecological groups and changes in types of ecological strategy of species, phytodiversity. We found 89 species of vascular plants. The most diverse families were Asteraceae, Poaceae and Lamiaceae. The biomorphological range of phytodiversity of the Tyasmyn valley is characterized by a high proportion of adventive and ruderal species, dominance of vegetative mobile species and disturbed distribution of all spectrum types for coenotic morphs. Depletion of the floristic composition and formation of monodominant groups in the middle of the valley were found. The overall measure of phytodiversity reached its maximum in the areas furthest from the mouth of the valley, lower towards the valley mouth and lowest in the area of pasture and recreational digression. Perennial hemicryptophytes and therophytes dominate the spectrum of life forms. Herbaceous plants without rosettes prevailed in the structure of above ground shoots and placement of leaves, while plants without special adaptations prevail in the structure of underground shoots. In the hydromorph structure with increasing distance from the mouth of the river there is a tendency for the share of hydrophytes, subhydrophytes to fall and, conversely, that of submesophytes to increase. Hygromesophytes and mesophytes prevail almost everywhere. Changes in the acidomorphic and nitromorphic structure of plants were not found. Semieutrophes, hemieurytopic, hemistenotopic plants and types of transitional groups of ecological strategies, including CR-, CS-, and CRS-strategies prevail. Vegetation of middle and lower flow of the river Tyasmyn degrades at stages II–IV of anthropogenic transformation.

Ecological Regime versus Minimum Environmental Flow:Comparison of Results for a River in a Semi Mediterranean Region

Maintaining Environmental Flow (EF) plays a critical role in protecting rivers and their ecosystems. Because of shortage of data and limited financial resources in developing countries, there is a tendency to use simple hydrologic methods against comprehensive EF assessment methods. In this research, two most common hydrologic methods (Tennant and Q95) were compared with a habitat simulation method (PHABSIM) under the condition of data shortage. It was concluded that while the results of habitat simulation method even using imprecise input data were justified, the impacts of implementing EF discharges of the two hydrologic methods on the ecosystem might be irreversible. It was found that the Tennant and Q95 methods led to dramatically low discharges as fixed minimum environmental flows, while habitat simulation method gave an acceptable ecological regime. In the absence of ecological data and after deciding on the target species in a case study in the southern part of the Caspian Sea, a special Delphi technique was employed for preparing the suitability data. For enhancing the PHABSIM hydraulic module results, HEC-RAS was implemented for hydraulic simulation and then with a simple modification on average velocity, the cross-sectional velocity distribution for deriving the Weighted Usable Area (WUA) was generated. It was found that this method along with maintaining high flows in the river preserved Mean Annual Flow (MAF) during wet months and preserved Mean Annual Low Flow (MALF) during dry months which is equal to maintaining Environmental Flow Requirement (EFR) in such a way that provides the river with an ecological regime near its historical one and guarantees river health.

Palaeoecological evidence for sustained change in a shallow Murray River (Australia) floodplain lake: regime shift or press response?

Paleolimnological techniques can reveal long-term perturbations and associated stable state transitions of lake ecosystems. However, such transitions are difficult to predict since changes to lake ecosystems can be abrupt or gradual. This study examined whether there were past transitions in the ecological regime of Kings Billabong, a shallow River Murray wetland in southeast Australia. A 94-cm-long core, covering c. 90 years of age, was analysed at 1 cm resolution for subfossil cladocerans, diatoms and other proxies. Prior to river regulation (c. 1930), the littoral to planktonic ratios of cladocerans and diatoms, and bulk sediment δ13C values were high, while the period from c. 1930 to c. 1970 experienced considerable changes to the wetland ecosystem. The abrupt nature of changes of planktonic cladocerans and diatoms, particularly after the onset of river regulation (1930s), was triggered by inundation, high rates of sedimentation and shifts in bulk sediment δ15N values. However, the transition of a once littoral-dominated community, to one favouring an increasingly turbid, plankton-dominated trophic condition following river regulation was relatively slow and lasted for decades. The progression to a new regime was likely delayed by the partial recovery of submerged plant communities and related internal dynamics.

Assessment of the role of reservoir morphology in parameterizing its ecological regime under extreme hydrological conditions

The results are presented of scenario calculations of water quality parameters and biological productivity in three areas of morphologically different types of reservoirs in the years with extreme water conditions. Three models of reservoirs with the same size and flowage are used: river-, lake-, and mixed-type reservoirs. The study is based on the morphometric parameters and bathygraphical curves from 18 stretches of the Mozhaisk Reservoir. The revealed differences in the intensity of algae bloom and anoxia in hypolimnion in the simulated reservoirs are compared with the criteria of the norm and risk of the ecological regime of the reservoirs being the sources of municipal water supply.

Biological invasions, ecological resilience and adaptive governance

In a world of increasing interconnections in global trade as well as rapid change in climate and land cover, the accelerating introduction and spread of invasive species is a critical concern due to associated negative social and ecological impacts, both real and perceived. Much of the societal response to invasive species to date has been associated with negative economic consequences of invasions. This response has shaped a war-like approach to addressing invasions, one with an agenda of eradications and intense ecological restoration efforts towards prior or more desirable ecological regimes. This trajectory often ignores the concept of ecological resilience and associated approaches of resilience-based governance. We argue that the relationship between ecological resilience and invasive species has been understudied to the detriment of attempts to govern invasions, and that most management actions fail, primarily because they do not incorporate adaptive, learning-based approaches. Invasive species can decrease resilience by reducing the biodiversity that underpins ecological functions and processes, making ecosystems more prone to regime shifts. However, invasions do not always result in a shift to an alternative regime; invasions can also increase resilience by introducing novelty, replacing lost ecological functions or adding redundancy that strengthens already existing structures and processes in an ecosystem. This paper examines the potential impacts of species invasions on the resilience of ecosystems and suggests that resilience-based approaches can inform policy by linking the governance of biological invasions to the negotiation of tradeoffs between ecosystem services.

A Novel, Unbiased Analysis Approach for Investigating Population Dynamics: A Case Study on Calanus finmarchicus and Its Decline in the North Sea.

Marine populations are controlled by a series of drivers, pertaining to both the physical environment and the biological environment (trophic predator-prey interactions). There is heated debate over drivers, especially when trying to understand the causes of major ecosystem events termed regime shifts. In this work, we have researched and developed a novel methodology based on Genetic Programming (GP) for distinguishing which drivers can influence species abundance. This methodology benefits of having no a priori assumptions either on the ecological parameters used or on the underlying mathematical relationships among them. We have validated this methodology applying it to the North Sea pelagic ecosystem. We use the target species Calanus finmarchicus, a key copepod in temperate and subarctic ecosystems, along with 86 biological, hydrographical and climatic time series, ranging from local water nutrients and fish predation, to large scale climate pressure patterns. The chosen study area is the central North Sea, from 1972 to 2011, during which period there was an ecological regime shift. The GP based analysis identified 3 likely drivers of C. finmarchicus abundance, which highlights the importance of considering both physical and trophic drivers: temperature, North Sea circulation (net flow into the North Atlantic), and predation (herring). No large scale climate patterns were selected, suggesting that when there is availability of both data types, local drivers are more important. The results produced by the GP based procedure are consistent with the literature published to date, and validate the use of GP for interpreting species dynamics. We propose that this methodology holds promises for the highly non-linear field of ecology.

Quantifying spatial resilience

Summary Anthropogenic stressors affect the ecosystems upon which humanity relies. In some cases when resilience is exceeded, relatively small linear changes in stressors can cause relatively abrupt and nonlinear changes in ecosystems. Ecological regime shifts occur when resilience is exceeded and ecosystems enter a new local equilibrium that differs in its structure and function from the previous state. Ecological resilience, the amount of disturbance that a system can withstand before it shifts into an alternative stability domain, is an important framework for understanding and managing ecological systems subject to collapse and reorganization. Recently, interest in the influence of spatial characteristics of landscapes on resilience has increased. Understanding how spatial structure and variation in relevant variables in landscapes affects resilience to disturbance will assist with resilience quantification, and with local and regional management. Synthesis and applications. We review the history and current status of spatial resilience in the research literature, expand upon existing literature to develop a more operational definition of spatial resilience, introduce additional elements of a spatial analytical approach to understanding resilience, present a framework for resilience operationalization and provide an overview of critical knowledge and technology gaps that should be addressed for the advancement of spatial resilience theory and its applications to management and conservation.

Length-Weight relationship of 57 freshwater fish species from three diverse ecological regimes in India

Length-weight relationship and condition factor in 57 freshwater fish species of 19 families and 38 genera from various rivers, and lakes of different climatic zones in India were studied. The estimates (total 67) for the parameter b of the length-weight relationship ranged between 1.422 and 3.917, with a mean value of 2.994. Correlation coefficient was found to be highly significant (r2 >0.90) in all except for Crossocheilus latius latius, Acanthocobitis botia and Garra lamta . Growth was found to be isometric (b = 3) in 32 species, positively allometric (b>3) in 21 species and negatively allometric (b<3) in 14 species. It was also found that some species exhibited variations in their growth pattern in different habitats, which showed the influence of preference and availability of suitable habitat conditions.

World-Ecology and Ireland: The Neoliberal Ecological Regime

Since the collapse of the Celtic Tiger, the socio-economic particularity of neoliberal capitalism in its Irish manifestation has increasingly been critiqued, but little attention has been paid to neoliberalism as ecology within Ireland. This article conducts an exploratory survey of the characteristics of the Irish neoliberal ecological regime during and after the Celtic Tiger, identifying the opening of new commodity frontiers (such as fracking, water, agro-biotechnology, and biopharma) constituted in the neoliberal drive to appropriate and financialize nature. I argue for the usefulness of applying not only the tools of world-systems analysis, but also Jason W. Moore’s world-ecological paradigm, to analysis of Ireland as a semi-periphery. What is crucial to a macro-ecological understanding of Ireland’s role in the neoliberal regime of the world-ecology is the inextricability of its financial role as a tax haven and secrecy jurisdiction zone from its environmental function as a semi-peripheral pollution and water haven. We can adapt Jason W. Moore’s slogan that “Wall Street…becomes a way of organizing all of nature, characterized by the financialization of any income-generating activity” (Moore 2011b: 39) to say that to say that the “IFSC is a way of organizing nature,” with pernicious consequences for water, energy, and food systems in Ireland. Financial service centers and pharmaceutical factories, plantations and cattle ranches, tax havens and pollution havens, empires and common markets are all forms of environment-making that constellate human relations and extra-human processes into new ecological regimes. More expansive, dialectical understandings of “ecology” as comprising the whole of socio-ecological relations within the capitalist world-ecology—from farming to pharma to financialization—are crucial to forming configurations of knowledge able not only to take account of Ireland’s role in the environmental history of capitalism, but also to respond to the urgent ecological crises of the neoliberal present.