نتایج جستجو برای: herbaceous species

تعداد نتایج: 550042  

Livestock grazing practices in rangelands are being recognized as management tool for environmental protection and increased livestock productivity. Continuous grazing has been largely reported to reduce pasture productivity and increase environmental degradation. Rotational grazing is an alternative to continuous grazing and is considered to reduce negative environmental effects and provide qu...

2014
Raúl Ochoa-Hueso Daniel de la Puente Ranea José Luis Viejo

Butterfly community and single species based approaches were taken to establish conservation priorities within a nature reserve in Central Spain. In this study, patch type (sclerophyllous, halophilous, or disturbed), potential herbaceous nectar availability, potential woody plant nectar availability, total nectar availability, and two approximations to plant diversity (herbaceous and woody plan...

Journal: :Environmental science & technology 2008
Zhi-Ping Wang Xing-Guo Han G Geoff Wang Yang Song Jay Gulledge

Traditionally, methane (CH4) emission from terrestrial plants is thought to originate from belowground microbial metabolism under anaerobic conditions, with subsequent transport to the atmosphere through stems. However, a recent study reported aerobic CH4 emission from plants by an unrecognized process, a result that has since been questioned. We investigated CH4 emissions under aerobic conditi...

2009
Pierre Hiernaux Augustine Ayantunde Adamou Kalilou Eric Mougin Frédéric Baup Manuela Grippa Bakary Djaby

To document trends in land use and herbaceous production, 71 field sites sampled among cropped fields, fallow fields and rangelands in the Fakara region (Niger) were monitored from 1994 to 2006. The overall trend in land use confirmed the historical increase of the cropped areas since mid 20th century, at an annual rate of 2% from 1994 to 2006. This trend is the result of changes in the relativ...

In order to investigate the diversity of plant species in forested areas, this study was carried out in forestry near the Khuzestan Steel Industries Company with a total area of 60 hectares in the southeast of Ahwaz, Khuzestan province. For this purpose, 30 plot of 20 × 20 meters in size were systematically randomized in the forested area and 30 samples were taken in the control area. Within ea...

Journal: :Ecology 2009
Keith M Vogelsang James D Bever

Belowground interactions between herbaceous native species and nonnative species is a poorly understood but emerging area of interest to invasive-species researchers. Positive feedback dynamics are commonly observed in many invaded systems and have been suspected in California grasslands, where native plants associate strongly with soil mutualists such as arbuscular mycorrhizal fungi. In respon...

2011
Nelson Ramírez Herbert Briceño

BACKGROUND AND AIMS Herbaceous-shrubby communities in the Gran Sabana (Great Savanna) Plateau of Venezuela grow under non-zonal conditions. We speculated that this would produce specific patterns of reproductive phenology within these different soil-climate-vegetation associations. Specifically, we tested the hypothesis that the reproductive phenology patterns of four herbaceous-shrubby communi...

2014
Andre F. Clewell

Shortleaf pine-oak-hickory woodlands provided the principal vegetation cover in the Tallahassee Red Hills prior to land clearing for plantation agriculture in the 19th century. Ample historical documentation and extant remnants of that community, including old-growth, support this conclusion. This woodland was maintained by surface fires and consisted principally of open stands of shortleaf pin...

Journal: :Theoretical population biology 2007
E Gilad M Shachak E Meron

A mathematical model for plant communities in water-limited systems is introduced and applied to a mixed woody-herbaceous community. Two feedbacks between biomass and water are found to be of crucial importance for understanding woody-herbaceous interactions: water uptake by plants' roots and increased water infiltration at vegetation patches. The former acts to increase interspecific competiti...

2011
Tesfay Yayneshet

Degradation of communal grazing land vegetation is a widespread problem throughout sub Saharan Africa and its restoration is a challenge for the management of many semi-arid areas. This study assessed the effectiveness of different age (young versus old) exclosures on species composition and diversity, biomass production and woody structure in northern Ethiopia. The species composition and dive...

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