نتایج جستجو برای: ecotone

تعداد نتایج: 925  

2017
Paul M. Montesano Guoqing Sun Ralph O. Dubayah K. Jon Ranson

In the taiga-tundra ecotone (TTE), site-dependent forest structure characteristics can influence the subtle and heterogeneous structural changes that occur across the broad circumpolar extent. Such changes may be related to ecotone form, described by the horizontal and vertical patterns of forest structure (e.g., tree cover, density and height) within TTE 10 forest patches, driven by local site...

2014
Shengwei Zong Zhengfang Wu Jiawei Xu Ming Li Xiaofeng Gao Hongshi He Haibo Du Lei Wang

Tree line ecotone in the Changbai Mountains has undergone large changes in the past decades. Tree locations show variations on the four sides of the mountains, especially on the northern and western sides, which has not been fully explained. Previous studies attributed such variations to the variations in temperature. However, in this study, we hypothesized that topographic controls were respon...

2007
W. Roush J. S. Munroe D. B. Fagre

Repeat photography is a powerful tool for detection of landscape change over decadal timescales. Here a novel method is presented that applies spatial analysis software to digital photo-pairs, allowing vegetation change to be categorized and quantified. This method is applied to 12 sites within the alpine treeline ecotone of Glacier National Park, Montana, and is used to examine vegetation chan...

Journal: :The American naturalist 2006
Erica Bree Rosenblum

Ecological transition zones, where organismal phenotypes result from a delicate balance between selection and migration, highlight the interplay of local adaptation and gene flow. Here, I study the response of an entire species assemblage to natural selection across a common ecotone. Three lizard species, distributed along a dramatic environmental gradient in substrate color, display convergent...

2013
David A. Lutz Rebecca L. Powell Miles R. Silman

Rapid 21st-century climate change may lead to large population decreases and extinction in tropical montane cloud forest species in the Andes. While prior research has focused on species migrations per se, ecotones may respond to different environmental factors than species. Even if species can migrate in response to climate change, if ecotones do not they can function as hard barriers to speci...

2008
Pascal Vittoz Benoît Rulence François Freléchoux

Tree growth is generally limited by temperature in cold climates and by water availability in arid zones. Establishment in altitudinal treeline ecotones depends on the temperature, but may be very sensitive to water availability as well. We studied the effect of climate and land use on the colonization and growth of Pinus cembra in the treeline ecotone of the dry Central Swiss Alps: one site wa...

2015
Jie Xue Dongwei Gui Ying Zhao Jiaqiang Lei Xinlong Feng Fanjiang Zeng Jie Zhou Donglei Mao Magaly Koch

Recently, a wide range of quantitative research on the identification of environmental flow requirements (EFRs) has been conducted. However, little focus is given to EFRs to maintain multiple ecosystem services in oasis areas. The present study quantifies the EFRs in oasis areas of Tarim Basin, Xinjiang, Northwest China on the basis of three ecosystem services: (1) maintenance of riverine ecosy...

2016
Yulia Ivanova Vlad Soukhovolsky

The ecological second-order phase transition model has been used to describe height-dependent changes in the species composition of mountain forest ecosystems. Forest inventory data on the distribution of various tree species in the Sayan Mountains (south Middle Siberia) are in good agreement with the model proposed in this study. The model was used to estimate critical heights for different al...

2015
Ricardo Moratelli Daniela Dias

We describe Lonchophyllainexpectata sp. n. from the Caatinga of Brazil. This new species can be distinguished from all known species of Lonchophylla that occur in Brazil by dental traits, cranial size, and fur colour. Specimens of Lonchophyllainexpectata have been misidentified as Lonchophyllamordax; but Lonchophyllainexpectata is a pale-venter species, similar in external appearance to Lonchop...

2011
John W. Williams Pavel Tarasov Simon Brewer Michael Notaro

[1] Accurate land cover reconstructions are essential to understanding the past and present biogeochemical and biogeophysical interactions between the land surface and atmosphere and the impacts of these interactions on climate. Here we quantitatively reconstruct late Quaternary shifts in woody cover across the Northern Hemisphere forest‐tundra ecotone, based on a synthesis of Northern Hemisphe...

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