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Full-Text Articles in Geography
Randomization Tests For Quantifying Species Importance To Ecosystem Function, Nicholas J. Gotelli, Werner Ulrich, Fernando T. Maestre
Randomization Tests For Quantifying Species Importance To Ecosystem Function, Nicholas J. Gotelli, Werner Ulrich, Fernando T. Maestre
College of Arts and Sciences Faculty Publications
1. Quantifying the contribution of different species to ecosystem function is an important challenge. We introduce simple randomization tests (and software) for quantifying the average effect of species on ecosystem variables measured in multiple plots with and without the presence of a particular species. These randomization tests formalize the analysis of uncontrolled 'natural experiments' and quantify species effects in standardized deviation units. 2.We tested the method with data on ecosystem function in biological soil crust assemblages of lichens in semi-arid gypsum outcrops in central Spain. In sixty-three 50cm×50cm sample plots, we measured the presence and percentage cover of 17 species …
Heating Up The Forest: Open-Top Chamber Warming Manipulation Of Arthropod Communities At Harvard And Duke Forests, Shannon L. Pelini, Francis P. Bowles, Aaron M. Ellison, Nicholas J. Gotelli, Nathan J. Sanders, Robert R. Dunn
Heating Up The Forest: Open-Top Chamber Warming Manipulation Of Arthropod Communities At Harvard And Duke Forests, Shannon L. Pelini, Francis P. Bowles, Aaron M. Ellison, Nicholas J. Gotelli, Nathan J. Sanders, Robert R. Dunn
College of Arts and Sciences Faculty Publications
1.Recent observations indicate that climatic change is altering biodiversity, and models suggest that the consequences of climate change will differ across latitude. However, long-term experimental field manipulations that directly test the predictions about organisms' responses to climate change across latitude are lacking. Such experiments could provide a more mechanistic understanding of the consequences of climate change on ecological communities and subsequent changes in ecosystem processes, facilitating better predictions of the effects of future climate change. 2.This field experiment uses octagonal, 5-m-diameter (c.22m 3) open-top chambers to simulate warming at northern (Harvard Forest, Massachusetts) and southern (Duke Forest, North Carolina) hardwood …