نتایج جستجو برای: grasslands

تعداد نتایج: 6042  

Features provide a comprehensive global overview of extent and diversity of grasslands. Analyzes how humans shaped grasslands through millennia of use and which role they play in present-day agriculture. Quantifies the role of grasslands as biodiversity hotspots as well as the drivers threatening these. Evaluates the ecosystem services grasslands provide e.g. in terms of soil protection and car...

2014
John Blair Jesse Nippert

• Grasslands are one of Earth’s major biomes and the native vegetation of up to 40 % of Earth’s terrestrial surface. Grasslands occur on every continent except Antarctica, are ecologically and economically important, and provide critical ecosystem goods and services at local, regional, and global scales. • Grasslands are surprisingly diverse and difficult to define. Although grasses and other g...

2016
M. D. Petrie N. A. Brunsell R. Vargas S. L. Collins L. B. Flanagan N. P. Hanan M. E. Litvak A. E. Suyker

In the Great Plains, grassland carbon dynamics differ across broad gradients of precipitation and temperature, yet finer-scale variation in these variables may also affect grassland processes. Despite the importance of grasslands, there is little information on how fine-scale relationships compare between them regionally. We compared grassland C exchanges, energy partitioning and precipitation ...

Journal: :journal of crop protection 2014
yousef panahandeh ebrahim pourjam

six belonolaim species were collected from grasslands of sabalan region. the found species belong to genera amplimerlinius, merlinius, nagelus, neodolichorhynchus, paramerlinius and tylenchorhynchus. among the found species, neodolichorhynchus judithae is reported for the first time from iran and is characterized byhaving offset head, cuticule with 16 longitudinal ridges, delicate stylet 21-23 ...

2005
Jon E. Keeley Philip W. Rundel

Jon E. Keeley and Philip W. Rundel US Geological Survey, Western Ecological Research Center, Sequoia-Kings Canyon Field Station, Three Rivers, CA 93271, USA Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA 90095-1606, USA Center for Embedded Networked Sensing, University of California, Los Angeles, CA 90095-1606, USA *Correspondence: E-mail: jon_keeley@u...

2016
S. Z. Sattari A. F. Bouwman R. Martinez Rodríguez A. H. W. Beusen M. K. van Ittersum

Grasslands provide grass and fodder to sustain the growing need for ruminant meat and milk. Soil nutrients in grasslands are removed through withdrawal in these livestock products and through animal manure that originates from grasslands and is spread in croplands. This leads to loss of soil fertility, because globally most grasslands receive no mineral fertilizer. Here we show that phosphorus ...

2014
Chuanjiang Tang Xinyu Fu Dong Jiang Jingying Fu Xinyue Zhang Su Zhou

Net primary productivity (NPP) is an important indicator for grassland resource management and sustainable development. In this paper, the NPP of Sichuan grasslands was estimated by the Carnegie-Ames-Stanford Approach (CASA) model. The results were validated with in situ data. The overall precision reached 70%; alpine meadow had the highest precision at greater than 75%, among the three types o...

Journal: :Ecology 2015
Leanne M Martin Brian J Wilsey

Biodiversity can be partitioned into alpha, beta, and gamma components, and beta diversity is not as clearly understood. Biotic homogenization predicts that exotic species should lower beta diversity at global and continental scales, but it is still unclear how exotic species impact beta diversity at smaller scales. Exotic species could theoretically increase or decrease beta diversity relative...

Journal: :journal of agricultural science and technology 2014
y. panahandeh e. pourjam m. pedram

four tylenchid species, namely, aglenchus agricola, malenchus exiguus, psilenchus curcumerus, and p. terextremus are reported from iran. the iranian population of a. agricola is characterized by 542-659 µm long body, 10-12 µm long stylet, excretory pore at 70-87 µm distance from anterior end, prominent lateral fields, with four lines, tail of 170-198 long, and rare males with 15-20 µm long spic...

2013
Vincent Bretagnolle

Effective solutions for integrating agricultural development and conservation of biodiversity at the landscape scale remain to be identified. We present a case study in an intensively farmed French cereal plain, where the reintroduction of grasslands has been proposed first for conservation purposes in order to protect the Little Bustard, a highly threatened bird species. Monitoring the effects...

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