نتایج جستجو برای: environmental variation

تعداد نتایج: 647156  

Journal: :Proceedings. Biological sciences 2013
Claire A Baldeck Kyle E Harms Joseph B Yavitt Robert John Benjamin L Turner Renato Valencia Hugo Navarrete Stuart J Davies George B Chuyong David Kenfack Duncan W Thomas Sumedha Madawala Nimal Gunatilleke Savitri Gunatilleke Sarayudh Bunyavejchewin Somboon Kiratiprayoon Adzmi Yaacob Mohd N Nur Supardi James W Dalling

Both habitat filtering and dispersal limitation influence the compositional structure of forest communities, but previous studies examining the relative contributions of these processes with variation partitioning have primarily used topography to represent the influence of the environment. Here, we bring together data on both topography and soil resource variation within eight large (24-50 ha)...

Journal: :Twin research and human genetics : the official journal of the International Society for Twin Studies 2013
Saskia J te Velde Niels van der Aa Dorret I Boomsma Eus J W van Someren Eco J C de Geus Johannes Brug Meike Bartels

This study assessed to what extent genetic and environmental factors contributed to individual differences in adolescent sleep duration, and whether genetic and environmental contributions to sleep duration changed throughout adolescence. A twin-family design was used to gain insight into the genetic and environmental contributions to variation in sleep duration. The study sample consisted of 6...

2013
Sarah J. Richardson Robert B. Allen Rowan P. Buxton Tomás A. Easdale Jennifer M. Hurst Christopher W. Morse Rob D. Smissen Duane A. Peltzer

Plant functional traits capture important variation in plant strategy and function. Recent literature has revealed that within-species variation in traits is greater than previously supposed. However, we still have a poor understanding of how intraspecific variation is coordinated among different traits, and how it is driven by environment. We quantified intraspecific variation in wood density ...

2016
Margot Neyret Lisa Patrick Bentley Imma Oliveras Beatriz S. Marimon Ben Hur Marimon‐Junior Edmar Almeida de Oliveira Fábio Barbosa Passos Rosa Castro Ccoscco Josias dos Santos Simone Matias Reis Paulo S. Morandi Gloria Rayme Paucar Arturo Robles Cáceres Yolvi Valdez Tejeira Yovana Yllanes Choque Norma Salinas Alexander Shenkin Gregory P. Asner Sandra Díaz Brian J. Enquist Yadvinder Malhi

Understanding variation in key functional traits across gradients in high diversity systems and the ecology of community changes along gradients in these systems is crucial in light of conservation and climate change. We examined inter- and intraspecific variation in leaf mass per area (LMA) of sun and shade leaves along a 3330-m elevation gradient in Peru, and in sun leaves across a forest-sav...

2014
Esperanza Manzano-Piedras Arnald Marcer Carlos Alonso-Blanco F. Xavier Picó

The role that different life-history traits may have in the process of adaptation caused by divergent selection can be assessed by using extensive collections of geographically-explicit populations. This is because adaptive phenotypic variation shifts gradually across space as a result of the geographic patterns of variation in environmental selective pressures. Hence, large-scale experiments a...

This study aimed to assess ecological quality status of hard substratum macroinvertebrates communities of the Caspian Sea with three ecological indices and their relation with environmental factors. For this purpose benthic communities of the Caspian Sea basin were studied seasonally during 2014 in 8 sampling sites. Temperature, salinity, dissolved oxygen, pH, nitrate, nitrite, silicate and pho...

ژورنال: فیزیک زمین و فضا 2016

This study, adopting an environmental approach to atmospheric circulation, estimates drought periods over a 20-year period (1992-2011) in 21 synoptic stations in Kerman, Yazd and Isfahan provinces, which share a long-term statistical period, using Standardized Precipitation Index (SPI). The data pertinent to 18 teleconnection patterns were derived and compared with climatic data of provinces un...

2016
Laura M. Cisneros Matthew E. Fagan Michael R. Willig

BACKGROUND Assembly of species into communities following human disturbance (e.g., deforestation, fragmentation) may be governed by spatial (e.g., dispersal) or environmental (e.g., niche partitioning) mechanisms. Variation partitioning has been used to broadly disentangle spatial and environmental mechanisms, and approaches utilizing functional and phylogenetic characteristics of communities h...

Journal: :Global change biology 2013
Jessica D Pratt Kailen A Mooney

Local adaptation and plasticity pose significant obstacles to predicting plant responses to future climates. Although local adaptation and plasticity in plant functional traits have been documented for many species, less is known about population-level variation in plasticity and whether such variation is driven by adaptation to environmental variation. We examined clinal variation in traits an...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 1976
P R Grant B R Grant J N Smith I J Abbott L K Abbott

Van Valen's model, which relates morphological variation to ecological variation in an adaptive scheme, was investigated with individually marked and measured Darwin's finches on two adjacent Galápagos islands, Santa Cruz and Daphne Major. Results show that environmental heterogeneity is correlated with large continuous, morphological variation: variation in bill dimensions of Geospiza fortis i...

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