Consulta: subjectFacets:"Null model"
Registros recuperados: 5
Data/hora: 08/06/2024 16:44:25

A Fractal Landscape Realizer for Generating Synthetic Maps
Provedor de dados: 7
Autores: Hargrove, William; Oak Ridge National Laboratory; hnw@fire.esd.ornl.gov; Hoffman, Forrest M; Oak Ridge National Laboratory;; Schwartz, Paul M; ;.
A fractal landscape realizer has been developed that generates synthetic landscape maps to user specifications. The alternative landscape realizations are not identical to the actual maps after which they are patterned, but are similar statistically (i.e., the areas and fractal character of each category are replicated). A fractal or self-affine pattern generator is used to provide a spatial probability surface for each category in the synthetic map. The Fractal Realizer arbitrates contentions among categories in a way that makes it possible to preserve the fractal patterns of all the categories in the resulting synthetic landscape. Each synthetic landscape is one equally likely realization from among an infinite ensemble of possible fractal landscape...
Tipo: Peer-Reviewed Reports
Palavras-chave: FRAGSTATS; Fractal Realizer; Turing Test; Categorical maps; Fractal; Landscape ecology; Neutral model; Null model; Pattern; Pseudoreplication; Realization; Simulation; Synthetic map.
Ano: 2002

Climate change may have minor impact on zooplankton functional diversity in the Mediterranean Sea
Provedor de dados: 5
Autores: Benedetti, Fabio; Ayata, Sakina-dorothee; Irisson, Jean-olivier; Adloff, Fanny; Guilhaumon, Francois.
Aim To assess the impact of climate change on the functional diversity of marine zooplankton communities. Location The Mediterranean Sea. Methods We used the functional traits and geographic distributions of 106 copepod species to estimate the zooplankton functional diversity of Mediterranean surface assemblages for the 1965-1994 and 2069-2098 periods. Multiple environmental niche models were trained at the global scale to project the species habitat suitability in the Mediterranean Sea and assess their sensitivity to climate change predicted by several scenarios. Simultaneously, the species traits were used to compute a functional dendrogram from which we identified seven functional groups and estimated functional diversity through Faith's index. We...
Tipo: Text
Palavras-chave: Climate change; Functional diversity; Mediterranean Sea; Niche modelling; Null model; Zooplankton.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00490/60118/63460.pdf

Assembly rules in Muscid Fly assemblages in the grasslands Biome of Southern Brazil
Provedor de dados: 82
Autores: Krüger,Rodrigo F; Carvalho,Claudio J B de; Ribeiro,Paulo B.
The distribution of muscid species (Diptera) in grasslands fragments of southern Brazil was assessed using null models according to three assembly rules: (a) negatively-associated distributions; (b) guild proportionality; and (c) constant body-size ratios. We built presence/absence matrices and calculated the C-score index to test negatively-associated distributions and guild proportionality based on the following algorithms: total number of fixed lines (F L), total number of fi xed columns (F C), and the effect of the average size of the populations along lines (W) for 5000 randomizations. We used null models to generate random communities that were not structured by competition and evaluated the patterns generated using three models: general, trophic...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Community; Competition; Diptera; Muscidae; Niche theory; Null model.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1519-566X2010000300006

Bird species diversity in the Atlantic Forest of Brazil is not explained by the Mid-domain Effect
Provedor de dados: 103
Autores: Cavarzere,Vagner; Silveira,Luís Fábio.
The Atlantic Forest is an excellent case study for the elevational diversity of birds, and some inventories along elevational gradients have been carried out in Brazil. Since none of these studies explain the patterns of species richness with elevation, we herein review all Brazilian studies on bird elevational diversity, and test a geometric constraint null model that predicts a unimodal species-altitude curve, the Mid-domain Effect (MDE). We searched for bird inventories in the literature and also analysed our own survey data using limited-radius point counts along an 800 m elevational gradient in the state of São Paulo, Brazil. We found 10 investigations of elevational diversity of Atlantic Forest birds and identified five different elevational...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Altitudinal gradient; Avian species richness; Geometric constraints; Mountain ecology; Null model; Rain forest.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-46702012000400001

Species assemblages of zooplanktonic crustaceans in mountain shallow ponds of Chile (Parque Cañi)
Provedor de dados: 103
Autores: Ríos,Patricio De los; Roa,Guido.
Even though the Chilean lakes are characterized by their oligotrophy, a transition from oligotrophy to mesotrophy, due human intervention, has been reported in some lakes. Nevertheless, there are still some pristine and unpolluted small lakes and ponds in mountain zones, free of human intervention and surrounded by native forests. Nine unpolluted, oligotrophic and pristine water bodies located in Cañi Park, a mountain zone with altitudes between 1000 to 1500 m a.s.l and forests where Nothofagus dombeyi, N. pumilio and Araucaria araucana predominate, were studied. For each sampled lake, zooplankton was collected and environmental parameters were obtained (conductivity, total dissolved solids, and chlorophyll concentration). A null model of species...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Boeckella gracilis; Null model; Oligotrophy; Zooplankton.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-46702010000100012