نتایج جستجو برای: plant cover

تعداد نتایج: 497813  

2006
ANDREW J. ELMORE SARA J. MANNING JOHN F. MUSTARD JOSEPH M. CRAINE

1. Throughout arid regions of the world, groundwater is extracted for human population centres. In the Great Basin and Range region of the USA, we lack basic information regarding some plant communities detailing the extent to which vegetation is threatened by groundwater extraction. This is particularly true for alkali meadow vegetation, which is restricted to zones of shallow groundwater yet ...

Journal: :پژوهش های تولید گیاهی 0

in order to investigate genetic correlation and path analysis between grain yield and yield components, fifteen early maturing hybrids of grain corn (zea. mays) using a randomized complete block design with 4 replications were evaluated in khoramabad agricultural research center, iran. the data were collected and analyzed for ear emergence date, anthesis date, maturity date, plant height, ear h...

2013
Lackson Chama Dana G. Berens Colleen T. Downs Nina Farwig

Plant-frugivore networks play a key role in the regeneration of sub-tropical forest ecosystems. However, information about the impact of habitat characteristics on plant-frugivore networks in fragmented forests is scarce. We investigated the importance of fruit abundance, fruiting plant species richness and canopy cover within habitat fragments for the structure and robustness of plant-frugivor...

2017
Daniel C. Laughlin Scott R. Abella Wallace Covington James B. Grace

Question: How are the effects of mineral soil properties on understory plant species richness propagated through a network of processes involving the forest overstory, soil organic matter, soil nitrogen, and understory plant abundance? Location: North-central Arizona, USA. Methods: We sampled 75 0.05-ha plots across a broad soil gradient in a Pinus ponderosa (ponderosa pine) forest ecosystem. W...

Adel Sepehry Hossein Barani Mohsen Sharafatmandrad,

In arid and semi-arid rangelands, grazing as one of the natural or human induced processes has direct and indirect effects on structure and dynamics of plant community and ecosystems. A study was done to analyze the effects of grazing on plant species diversity and Plant Functional Types‘ (PFTs) diversity of arid and semi-arid rangelands. We analyzed plant richness and diversity data from 75 sa...

2006
M. S. Thomsen K. McGlathery

Increases in sediment and drift algae accumulations have caused degradation of coastal lagoons worldwide. It is well known that these factors are stressors of seagrass beds, sediment fauna and coral reefs. However, little is known about the impacts on temperate hard-bottom assemblages within soft-bottom lagoons. To test if accumulations of sediment and drift algae (stress) affected recruitment ...

2017
Dylan Craven Madhav P. Thakur Erin K. Cameron Lee E. Frelich Robin Beauséjour Robert B. Blair Bernd Blossey James Burtis Amy Choi Andrea Dávalos Timothy J. Fahey Nicholas A. Fisichelli Kevin Gibson I. Tanya Handa Kristine Hopfensperger Scott R. Loss Victoria Nuzzo John C. Maerz Tara Sackett Bryant C. Scharenbroch Sandy M. Smith Mark Vellend Lauren G. Umek Nico Eisenhauer

Globally, biological invasions can have strong impacts on biodiversity as well as ecosystem functioning. While less conspicuous than introduced aboveground organisms, introduced belowground organisms may have similarly strong effects. Here, we synthesize for the first time the impacts of introduced earthworms on plant diversity and community composition in North American forests. We conducted a...

Journal: :تولید گیاهان زراعی 0
گودرز احمدوند دانشیار گروه زراعت و اصلاح نباتات، دانشکده کشاورزی، دانشگاه بوعلی سینا همدان سمیه حاجی نیا دانشجوی دکتری فیزیولوژی گیاهان زراعی، دانشکده کشاورزی، دانشگاه بوعلی سینا

background and objectives: suitable tillage methods and planting cover crops are such factors in sustainable agricultural systems, which play an important role in the sustainability of agricultural production systems. minimum and no-tillage systems methods that leave instead of usually more than 30 percent of crop residue on the soil surface, are used to reduce soil erosion, improve soil physic...

2008
Murat Demir Ender Makineci Beyza Sat Gungor

This study was executed to determine the plant species of herbaceous cover in a skid road subjected to soil compaction due to timber skidding in a beech (Fagus orientalis Lipsky.) stand. Our previous studies have shown that ground based timber skidding destroys the soils extremely, and degradations on ecosystem because of the timber skidding limit recovery and growth of plant cover on skid road...

Journal: :Remote Sensing 2016
Alexander Kozlov Maria Kozlova Nikolai Skorik

The paper reports a technique used to construct a reference time series for the fraction of absorbed photosynthetically-active radiation (FAPAR) based on remotely-sensed data in the largest Russian arid wetland territory. For the arid Volga-Akhtuba wetlands, FAPAR appears to be an informative spectral index for estimating plant cover health and its seasonal and annual dynamics. Since FAPAR algo...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید