نتایج جستجو برای: ecological disturbances

تعداد نتایج: 146768  

Journal: :Journal of oceanology and limnology 2021

The modern landscape patterns of islands usually show obvious spatial heterogeneity and complex ecological effects due to the vulnerability ecosystems with natural characteristics under increasing human activities. In this work, we studied variation in pattern Miaodao Archipelago Bohai Sea, North China, from 1990 2019, an evaluation index system was established explore impacts conditions distur...

Journal: :Behaviour 2021

Abstract Many wild populations of animals conform to the ideal despotic distribution (IDD) in which more competitive individuals exclude less from high quality resources. Body size and aggressiveness are two important traits for resource defense, they positively covary so that larger usually aggressive. Using Bachman’s sparrows, we tested hypothesis birds aggressive thus able compete best terri...

Journal: :The Science of the total environment 2017
Travis W Nauman Michael C Duniway Miguel L Villarreal Travis B Poitras

A new disturbance automated reference toolset (DART) was developed to monitor human land surface impacts using soil-type and ecological context. DART identifies reference areas with similar soils, topography, and geology; and compares the disturbance condition to the reference area condition using a quantile-based approach based on a satellite vegetation index. DART was able to represent 26-55%...

2016
Giovanni Strona Achille Mauri Joseph A. Veech Günther Seufert Jesus San-Miguel Ayanz Simone Fattorini

Contemporaneous plant communities may retain a mark of past disturbances in their ecological patterns. However, unraveling the history of disturbance on natural systems at a large scale is often unfeasible, due to the complexity of the factors involved and lack of historical data. Here we aim at demonstrating how comparing observed spatial structure of tree assemblages with that expected in a h...

2015
Nian-Feng Wan Xiang-Yun Ji Jie-Xian Jiang Bo Li

The extensive use of chemical pesticides for pest management in agricultural systems can entail risks to the complex ecosystems consisting of economic, ecological and social subsystems. To analyze the negative and positive effects of external or internal disturbances on complex ecosystems, we proposed an ecological two-sidedness approach which has been applied to the design of pest-controlling ...

Journal: :Ecology 2009
Melinda D Smith Alan K Knapp Scott L Collins

In contrast to pulses in resource availability following disturbance events, many of the most pressing global changes, such as elevated atmospheric carbon dioxide concentrations and nitrogen deposition, lead to chronic and often cumulative alterations in available resources. Therefore, predicting ecological responses to these chronic resource alterations will require the modification of existin...

Journal: :Journal of environmental management 2014
Michael G Sorice Urs P Kreuter Bradford P Wilcox William E Fox

Motivations for owning rural land are shifting from an agricultural-production orientation to a preference for natural and cultural amenities. Resultant changes in land management have significant implications for the type and distribution of landscape-level disturbances that affect the delivery of ecosystem services. We examined the relationship between motivations for owning land and the impl...

2009
John Eid

www.sciencemag.org (this information is current as of February 2, 2009 ): The following resources related to this article are available online at http://www.sciencemag.org/cgi/content/full/323/5910/133 version of this article at: including high-resolution figures, can be found in the online Updated information and services, http://www.sciencemag.org/cgi/content/full/1162986/DC1 can be found at:...

Journal: :Ecology letters 2008
Jennifer M Fraterrigo James A Rusak

Understanding how disturbance shapes the dynamics of ecological systems is of fundamental importance in ecology. One emerging approach to revealing and appreciating disturbance effects involves examining disturbance-driven changes in the variability of ecological responses. Variability is rarely employed as a response variable to assess the influence of disturbance, but recent studies indicate ...

2015
Hugo Ducasse Audrey Arnal Marion Vittecoq Simon P Daoust Beata Ujvari Camille Jacqueline Tazzio Tissot Paul Ewald Robert A Gatenby Kayla C King François Bonhomme Jacques Brodeur François Renaud Eric Solary Benjamin Roche Frédéric Thomas

For an increasing number of biologists, cancer is viewed as a dynamic system governed by evolutionary and ecological principles. Throughout most of human history, cancer was an uncommon cause of death and it is generally accepted that common components of modern culture, including increased physiological stresses and caloric intake, favor cancer development. However, the precise mechanisms for ...

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