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51.
The establishment of marine protected areas (MPAs) is a critical step in ensuring the continued persistence of marine biodiversity. Although the area protected in MPAs is growing, the movement of individuals (or larvae) among MPAs, termed connectivity, has only recently been included as an objective of many MPAs. As such, assessing connectivity is often neglected or oversimplified in the planning process. For promoting population persistence, it is important to ensure that protected areas in a system are functionally connected through dispersal or adult movement. We devised a multi-species model of larval dispersal for the Australian marine environment to evaluate how much local scale connectivity is protected in MPAs and determine whether the extensive system of MPAs truly functions as a network. We focused on non-migratory species with simplified larval behaviors (i.e., passive larval dispersal) (e.g., no explicit vertical migration) as an illustration. Of all the MPAs analyzed (approximately 2.7 million km2), outside the Great Barrier Reef and Ningaloo Reef, <50% of MPAs (46-80% of total MPA area depending on the species considered) were functionally connected. Our results suggest that Australia's MPA system cannot be referred to as a single network, but rather a collection of numerous smaller networks delineated by natural breaks in the connectivity of reef habitat. Depending on the dispersal capacity of the taxa of interest, there may be between 25 and 47 individual ecological networks distributed across the Australian marine environment. The need to first assess the underlying natural connectivity of a study system prior to implementing new MPAs represents a key research priority for strategically enlarging MPA networks. Our findings highlight the benefits of integrating multi-species connectivity into conservation planning to identify opportunities to better incorporate connectivity into the design of MPA systems and thus to increase their capacity to support long-term, sustainable biodiversity outcomes. 相似文献
52.
Climatic warming is associated with organisms breeding earlier in the season than is typical for their species. In some species, however, response to warming is more complex than a simple advance in the timing of all life history events preceding reproduction. Disparities in the extent to which different components of the reproductive phenology of organisms vary with climatic warming indicate that not all life history events are equally responsive to environmental variation. Here, we propose that our understanding of phenological response to climate change can be improved by considering entire sequences of events comprising the aggregate life histories of organisms preceding reproduction. We present results of a two-year warming experiment conducted on 33 individuals of three plant species inhabiting a low-arctic site. Analysis of phenological sequences of three key events for each species revealed how the aggregate life histories preceding reproduction responded to warming, and which individual events exerted the greatest influence on aggregate life history variation. For alpine chickweed (Cerastium alpinum), warming elicited a shortening of the duration of the emergence stage by 2.5 days on average, but the aggregate life history did not differ between warmed and ambient plots. For gray willow (Salix glauca), however, all phenological events monitored occurred earlier on warmed than on ambient plots, and warming reduced the aggregate life history of this species by 22 days on average. Similarly, in dwarf birch (Betula nana), warming advanced flower bud set, blooming, and fruit set and reduced the aggregate life history by 27 days on average. Our approach provides important insight into life history responses of many organisms to climate change and other forms of environmental variation. Such insight may be compromised by considering changes in individual phenological events in isolation. 相似文献
53.
Phenology: response, driver, and integrator. 总被引:1,自引:0,他引:1
54.
Intraspecific variation in a predator affects community structure and cascading trophic interactions 总被引:1,自引:0,他引:1
Intraspecific phenotypic variation in ecologically important traits is widespread and important for evolutionary processes, but its effects on community and ecosystem processes are poorly understood. We use life history differences among populations of alewives, Alosa pseudoharengus, to test the effects of intraspecific phenotypic variation in a predator on pelagic zooplankton community structure and the strength of cascading trophic interactions. We focus on the effects of differences in (1) the duration of residence in fresh water (either seasonal or year-round) and (2) differences in foraging morphology, both of which may strongly influence interactions between alewives and their prey. We measured zooplankton community structure, algal biomass, and spring total phosphorus in lakes that contained landlocked, anadromous, or no alewives. Both the duration of residence and the intraspecific variation in foraging morphology strongly influenced zooplankton community structure. Lakes with landlocked alewives had small-bodied zooplankton year-round, and lakes with no alewives had large-bodied zooplankton year-round. In contrast, zooplankton communities in lakes with anadromous alewives cycled between large-bodied zooplankton in the winter and spring and small-bodied zooplankton in the summer. In summer, differences in feeding morphology of alewives caused zooplankton biomass to be lower and body size to be smaller in lakes with anadromous alewives than in lakes with landlocked alewives. Furthermore, intraspecific variation altered the strength of the trophic cascade caused by alewives. Our results demonstrate that intraspecific phenotypic variation of predators can regulate community structure and ecosystem processes by modifying the form and strength of complex trophic interactions. 相似文献
55.
错流式膜-生物反应器处理生活污水及其生物学研究 总被引:6,自引:5,他引:6
用错流式膜-生物反应器(CrosflowMembraneBioReactor简称CMBR)进行处理生活污水试验并研究其生物动力学参数.结果表明:当HRT为5h,SRT为15d,膜面流速为4m/s,膜通量为75、150L/(m2·h)时,CMBR处理生活污水试验的去除率为:COD>97%、NH3-N>97%、浊度≥98%;对SS和总E.coli则达到100%,出水水质优于建设部生活杂用水回用标准CJ25.1-89.生物相分析表明,污泥中没有原、后生动物,只有菌胶团.推导了CMBR稳态运行时的生物浓度计算公式,进而求得表观产率因数Yg为0.65,衰减常数Kd为0.1d-1. 相似文献
56.
Although microbial transformations via cometabolism have been widely observed, the few available kinetic models of cometabolism have not adequately addressed the case of inhibition from both the growth and nongrowth substrates. The present study investigated the degradation kinetics of self-inhibitory growth (phenol) and nongrowth (4-chlorophenol, 4-CP) substrates, present individually and in combination. Specifically, batch experiments were performed using an Acinetobacter isolate growing on phenol alone and with 4-CP present. In addition, batch experiments were also performed to evaluate the transformation of 4-CP by resting, phenol-induced Acinetobacter cultures. The Haldane kinetic model adequately predicted the biodegradation of phenol alone, although a slight discrepancy was noted in cases of higher initial phenol concentrations. Similarly, a Haldane model for substrate utilization was also able to describe the trends in 4-CP transformation by the resting cell cultures. The 4-CP transformation by the Acinetobacter species growing on phenol was modeled using a competitive kinetic model of cometabolism, which included growth and nongrowth substrate inhibition and cross-inhibition terms. Excellent agreement was obtained between the model predictions using experimentally estimated parameter values and the experimental data for the synchronous disappearance of phenol and 4-CP. 相似文献
57.
58.
Ghosh Shreya Gandhi Mayuri van Hullebusch Eric D. Das Alok Prasad 《Environmental science and pollution research international》2021,28(30):40249-40263
Environmental Science and Pollution Research - There has been alarming depletion of manganese (Mn) reserves owing to the ongoing extensive mining operations for catering the massive industrial... 相似文献
59.
Environmental degradation by mud in tropical estuaries 总被引:3,自引:0,他引:3
In wet tropical countries, the intense rainfall and the lack of effective restrictions on human activities in the river catchment
leads to increased rates of soil erosion. This has increased the sediment loads many times over from the natural level. As
a result, estuarine and coastal waters are becoming increasingly muddy with associated losses for society in terms of increased
flooding and a degradation of the environment, the fisheries and the economic use of these waters. It is suggested that science-based
models be used to predict the fate of mud in estuaries and coastal waters when planning development in river catchments, particularly
in wet tropical countries. This would help integrate land and water management. Modelling technology is demonstrated by a
combination of field and model studies in four turbid tropical estuaries, namely the Fly River in Papua New Guinea, the Mekong
River in Vietnam, the Cimanuk River in Indonesia, and Hinchinbrook Channel in Australia. The final model is adapted to local
conditions and extensively uses data assimilation especially for open boundary conditions. There can be a feedback between
the hydrodynamics and the mud dynamics when the system silts; in wet tropical countries this can occur rapidly, sometimes
in only 30 years.
Electronic Publication 相似文献
60.
Eric D. Carter 《Local Environment》2016,21(1):3-23
This paper presents the results of ethnographic research conducted with several environmental justice (EJ) organisations in Latino communities of Los Angeles, California. Traditional EJ politics revolves around research and advocacy to reduce discriminatory environmental exposures, risks, and impacts. However, I argue that in recent years there has been a qualitative change in EJ politics, characterised by four main elements: (1) a move away from the reaction to urban environmental “bads” (e.g. polluting industries) in the city towards a focus on the production of nature in the city; (2) strategies that are less dependent on the legal, bureaucratic, and technical “regulatory route”; (3) the formation of a distinctive “Latino environmental ethic” that offers a more complex consideration of the place of race in EJ organising; and (4) a spatial organisation of EJ politics that moves away from hyperlocal, vertical organisation towards diversified city-wide networks that include EJ organisations, mainstream environmental groups, nonprofits, foundations, and entrepreneurs. This shift in EJ movement politics is shaped by broader political-economic changes, including the shift from post-Fordist to neoliberal and now green economy models of urban development; the influence of neoliberal multiculturalism in urban politics; and the increasingly prominent role of Latinos in city, state, and national politics. New spaces of Latino EJ also reflect the ambitions of Los Angeles as a global city, with urban growth increasingly framed in an international discourse of sustainability that combines quality of life, environmental, and economic development rationales. 相似文献