Ecological Applications
1939-5582
1051-0761
Mỹ
Cơ quản chủ quản: Wiley-Blackwell , WILEY
Lĩnh vực:
Ecology
Phân tích ảnh hưởng
Thông tin về tạp chí
The pages of Ecological Applications are open to research and discussion papers that integrate ecological science and concepts with their application and implications. Of special interest are papers that develop the basic scientific principles on which environmental decision-making should rest, and those that discuss the application of ecological concepts to environmental problem solving, policy, and management. Papers that deal explicitly with policy matters are welcome. Interdisciplinary approaches are encouraged, as are short communications on emerging environmental challenges.
Các bài báo tiêu biểu
Ecohydrological and socioeconomic integration for the operational management of environmental flows Investment in and operation of flow control infrastructure such as dams, weirs, and regulators can help increase both the health of regulated river ecosystems and the social values derived from them. This requires high‐quality and high‐resolution spatiotemporal ecohydrological and socioeconomic information. We developed such an information base for integrated environmental flow management in the River Murray in South Australia (SA). A hydrological model was used to identify spatiotemporal inundation dynamics. River ecosystems were classified and mapped as ecohydrological units. Ecological response models were developed to link three aspects of environmental flows (flood duration, timing, and inter‐flood period) to the health responses of 16 ecological components at various life stages. Potential infrastructure investments (flow control regulators and irrigation pump relocation) were located by interpreting LiDAR elevation data, digital orthophotography, and wetland mapping information; and infrastructure costs were quantified using engineering cost models. Social values were quantified at a coarse scale as total economic value based on a national survey of willingness‐to‐pay for four key ecological assets; and at a local scale using mapped ecosystem service values. This information was integrated using a constrained, nonlinear, mixed‐integer, compromise programming optimization model and solved using a stochastic Tabu search algorithm. We tested the model uncertainty and sensitivity using 390 Monte Carlo model runs at varying weights of ecological health vs. social values. Integrating ecohydrological and socioeconomic information identified environmental flow management regimes that efficiently achieved both ecological and social objectives. Using an ecologically weighted efficient and socially weighted efficient scenario, we illustrated model outputs including a suite of cost‐effective infrastructure investments and an operational plan for new and existing flow control structures including dam releases, weir height manipulation, and regulator operation on a monthly time step. Both the investments and management regimes differed substantially between the two scenarios, suggesting that the choice of weightings on ecological and social objectives is important. This demonstrates the benefit of integrating high‐quality and high‐resolution spatiotemporal ecohydrological and socioeconomic information for guiding the investment in and operational management of environmental flows.
Tập 23 Số 5 - Trang 999-1016 - 2013
ROADLESS HABITATS AS REFUGES FOR NATIVE GRASSLANDS: INTERACTIONS WITH SOIL, ASPECT, AND GRAZING
Tập 13 Số 2 - Trang 404-415 - 2003
MACROALGAL (FUCUS VESICULOSUS) δ<sup>15</sup>N VALUES TRACE DECREASE IN SEWAGE INFLUENCE Nutrient discharges from sewage treatment plants can contribute significantly to coastal and estuarine eutrophication. To counter anthropogenic nitrogen (N) loads in a Baltic Sea coastal embayment, improved (∼85%) N removal was implemented in a tertiary sewage‐treatment plant. This study used nitrogen stable‐isotope ratios (δ15 N) in attached brown macroalgae, Fucus vesiculosus , to map the change in the spatial extent of the influence of sewage‐derived N. Elevated N content and δ15 N values (δ15 N = 8–9‰) suggest that sewage N was still traceable in algal tissues despite enhanced N removal from the effluent. However, the δ15 N values decreased significantly with distance and approached background levels within 10–12 km of the outfall. Compared to a survey conducted in 1989, prior to enhanced N removal in the sewage treatment plant, macroalgae were 2.5–6‰ lower in δ15 N values within 24 km from the outfall, demonstrating a decline in the importance of sewage‐derived nutrients to macroalgae, particularly in the inner reaches of the bay. Beyond 25 km from the outfall, δ15 N values were at background levels (δ15 N = 4‰). Two‐source mixing models estimate that the percentage sewage contribution to total algal N uptake in algae near the outfall was ∼40% in 1989 and ∼12% in 1999. Similarly, temporal variation in individual plants estimate that the percentage sewage N contribution to algae within 1 km from the outfall declined from >40% in the mid‐1990s to ∼20% in 2002. Nutrient budget calculations showed that F. vesiculosus is not an effective sink for N, assimilating only ∼3% of total annual N loads entering the bay.
Tập 14 Số 2 - Trang 517-526 - 2004
Browsing and fire interact to suppress tree density in an African savanna Disturbances from fire and herbivory strongly affect savanna vegetation dynamics. In some savannas, fire especially may be instrumental in preserving the coexistence of trees and grasses. The role of herbivory by large mammals is less clear; herbivory has been shown variously to promote and to suppress tree establishment. Here we ask how interactions between herbivory and fire act to shape savanna vegetation dynamics via their effects on tree populations in Hluhluwe iMfolozi Park in KwaZulu Natal, South Africa, a savanna with a full complement of native large mammals. We examined the effects of herbivore exclusion on tree growth, mortality, and seedling establishment from 2000 to 2007 at 10 sites located in areas of low and high herbivore pressure throughout the park. Results were analyzed statistically and using Leslie matrix models of population dynamics. Herbivory and fire acted primarily to suppress sapling growth rather than on sapling mortality or seedling establishment. This indicates that browsing, like fire, suppresses tree density by imposing a demographic bottleneck on the maturation of saplings to adults. Model results suggest that, while browsing and fire each alone impacted growth, a combination of browsing and fire had much greater effects on tree density. Only fire and browsing together were able to prevent increases in tree density. These results suggest that, while soil resources, including nutrients and moisture, are probably instrumental in determining tree growth rates, disturbances from fire and herbivory may be instrumental in limiting tree cover and facilitating the coexistence of trees and grasses in savannas.
Tập 19 Số 7 - Trang 1909-1919 - 2009
THE VERTICAL DISTRIBUTION OF SOIL ORGANIC CARBON AND ITS RELATION TO CLIMATE AND VEGETATION
Tập 10 Số 2 - Trang 423-436 - 2000
INCORPORATING LANDSCAPE STOCHASTICITY INTO POPULATION VIABILITY ANALYSIS
Tập 17 Số 2 - Trang 317-322 - 2007
A Model of the Effects of Tillage on Emergence of Weed Seedlings A simple model is developed in which the density of weed seedlings emerging in a field is related to (1) the ability of seedlings to emerge from various depths in the soil, (2) the survival of seeds at different depths, and (3) the depth of seed burial in no tillage, rotary tillage, and plow tillage. Other tillage regimes are considered by analogy. Literature is reviewed to determine biologically reasonable functions describing seedling emergence, seed survival, and distribution of seeds with depth, and parameters of these equations are estimated from data in the literature. Problems related to the mathematical description of these phenomena are discussed, and it is noted that some commonly held beliefs regarding survival of seeds in the soil are mutually incompatible. Although many studies have investigated the persistence of seeds as a function of depth in the soil, few have distinguished death from the production of seedlings. The model indicates that in the first year following input of seeds to the soil, no tillage will have more seedlings than tillage, but in later years no tillage will likely have fewer seedlings unless innate or induced dormancy is high or seed survival near the soil surface is unusually good. If seed return is allowed, no tillage or minimum tillage will have more seedlings perennially. Recovery of good weed control following a year with substantial seed input may be easiest if the soil is plowed deeply to bury the seeds, and then shallow or no tillage is used in subsequent years to avoid returning seeds to the surface. Much of the literature on the effects of tillage on weed density is difficult to interpret because little indication is given of the vertical distribution of seeds in the soil at the beginning of the experiment.
Tập 3 Số 1 - Trang 53-73 - 1993
Estimating wind‐turbine‐caused bird and bat fatality when zero carcasses are observed Many wind‐power facilities in the United States have established effective monitoring programs to determine turbine‐caused fatality rates of birds and bats, but estimating the number of fatalities of rare species poses special difficulties. The loss of even small numbers of individuals may adversely affect fragile populations, but typically, few (if any) carcasses are observed during monitoring. If monitoring design results in only a small proportion of carcasses detected, then finding zero carcasses may give little assurance that the number of actual fatalities is small. Fatality monitoring at wind‐power facilities commonly involves conducting experiments to estimate the probability (g ) an individual will be observed, accounting for the possibilities that it falls in an unsearched area, is scavenged prior to detection, or remains undetected even when present. When g < 1, the total carcass count (X ) underestimates the total number of fatalities (M ). Total counts can be 0 when M is small or when M is large and g ≪1. Distinguishing these two cases is critical when estimating fatality of a rare species. Observing no individuals during searches may erroneously be interpreted as evidence of absence. We present an approach that uses Bayes' theorem to construct a posterior distribution for M , i.e., P (M | X , ĝ ), reflecting the observed carcass count and previously estimated g . From this distribution, we calculate two values important to conservation: the probability that M is below a predetermined limit and the upper bound (M * ) of the 100(1 − α)% credible interval for M . We investigate the dependence of M * on α, g , and the prior distribution of M , asking what value of g is required to attain a desired M * for a given α. We found that when g < −0.15, M * was clearly influenced by the mean and variance of ĝ and the choice of prior distribution for M , but the influence of these factors is minimal when g > −0.45. Further, we develop extensions for temporal replication that can inform prior distributions of M and methods for combining information across several areas or time periods. We apply the method to data collected at a wind‐power facility where scheduled searches yielded X = 0 raptor carcasses.
Tập 25 Số 5 - Trang 1213-1225 - 2015
The Statistical Evaluation of Ecological Indicators Ecological indicators are easily measured surrogates for underlying properties or responses of a system that are difficult to measure accurately and reliably. Methods from signal detection theory can be used to assess the usefulness of such indicators, based on pilot data sets in which some gold standard of the underlying response has been measured. For responses that can naturally be dichotomized (e.g., absent vs. present, or acceptable vs. unacceptable), we can estimate an indicator's sensitivity (the probability of a positive indicator, given that the true response is positive) and specificity (the probability of a negative indicator, given that the true responses is negative). These properties, together with the prevalence of the response in the population being studied, determine the indicator's predictive value (e.g., positive predictive value is the probability of a positive response, given that the indicator is positive). Applications of this methodology are described for two examples: the use of satellite imagery to infer oceanic pigment concentrations, and the use of baseline levels of acid‐neutralizing capacity (ANC) to anticipate acidification episodes in lakes and streams.
Tập 6 Số 1 - Trang 132-139 - 1996