نتایج جستجو برای: over grazing and improper irrigation method

تعداد نتایج: 17128064  

al. et G.B.G. Pananjay

Protected areas are major tourism assets for a nation, particularly for developing countries providing sustainable benefit to the local community while funding for the maintenance and rehabilitation of the protected areas themselves. Valley of flowers national park is naturally meant for the conservation and study of western Himalayan flora. It became National park in 1982 and after that livest...

Journal: :Ecological applications : a publication of the Ecological Society of America 2012
Orien M W Richmond Jerry Tecklin Steven R Beissinger

Impacts of livestock grazing in arid and semiarid environments are often concentrated in and around wetlands where animals congregate for water, cooler temperatures, and green forage. We assessed the impacts of winter-spring (November-May) cattle grazing on marsh vegetation cover and occupancy of a highly secretive marsh bird that relies on dense vegetation cover, the California Black Rail (Lat...

2016
Nandkishor More

Urban centers are unambiguously discharging wastewater in the natural streams, lakes, ponds and for irrigation in the agricultural fields. In the early stages of human civilization, wastewater discharges did not pose problem to water bodies as the nature had the capability for degradation and restoration of the quality of water to its normal condition.The key challenges towards better managemen...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شیراز - دانشکده علوم 1391

in this thesis, we exploit a simple and suitable method for immobilization of copper(ii) complex of 4?-phenyl-terpyridine on activated multi-walled carbon nanotubes [amwcnts-o-cu(ii)-phtpy]. this nanostructure was characterized by various physico-chemical techniques. to ensure the efficiency and fidelity of copper species, the implementation of three-component strategies in click-chemistry all...

Journal: Pollution 2017

In Nigeria irrigated agriculture is an important tool for economic growth, food security, and poverty reduction during dry periods of rain-fed agriculture. The concentration and composition of dissolved constituents in water determines its quality for irrigation use. Water quality studies strongly suggest that agriculture is a leading source of water quality problems, due to pesticides and othe...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه بیرجند - دانشکده علوم 1391

in this thesis, we consider a mathematical model of cancer with completely unknown parameters. we study the stability of critical points which are biologically admissible. then we consider a control on the system and introduce situations at which solutions are attracted to critical points and so the cancer disease has auto healing. the lyapunov stability method is used for estimating the un...

Journal: :journal of rangeland science 2013
mona fakhre ghazi mohammad hasan jouri vahid gholami

subalpine rangeland as a rara avis ecosystem is very important because ofecological features. consistency and resistance of this ecosystem is so frangible and itsnatural equilibrium is instable due to the effects of biotic and abiotic factors. the landslideas one of negative consequences in upland area is seen in masoleh watershed (north ofiran). this study has investigated the roles of biotic ...

2007
Richard A. Gill

Human communities in the Intermountain West depend heavily on subalpine rangelands because of their importance in providing water for irrigation and forage for wildlife and livestock. In addition, many constituencies are looking to managed ecosystems to sequester carbon in plant biomass and soil C to reduce the impact of anthropogenic CO2 on climate. This work builds on a 90-year-old grazing ex...

ژورنال: علوم آب و خاک 2012
فایز رئیسی, , مریم ریاحی, ,

Mountainous landscapes in Central Zagros are mainly used as grazing rangelands to feed animals and are heavily degraded. Overgrazing may impose a negative effect on rangeland productivity and sustainability through significant changes in soil properties. Soil nitrogen (N) mineralization is one of the key biological processes that might be affected by biotic and abiotic factors including range g...

ژورنال: :مجله گیاهشناسی ایران 2014
زمان شر فرخ حسین لال بدشاه

این مطالعه برای بررسی تنوع زیستی و مشخصات اکولوژیکی تپه های گادون در منطقه سوابی پاکستان در طی سالهای 2009 تا 2010 انجام شده است. این منطقه تحت تأثیر فشارهای زیستی بدلیل از بین رفتن جنگلها و چرای بیش از حد می باشد. پوشش گیاهی منطقه دامنه وسیعی از اشکال زیستی از انواع چمن ها تا درخت بلند را در بر می گیرد. 260 گونه گیاهی متعلق به 211 جنس و 90 خانواده شناسایی گردیدند. هفتاد و هفت خانواده از دو لپه...

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