نتایج جستجو برای: destruction of natural habitats

تعداد نتایج: 21201521  

2000
Joshua Sinai

Since the late 1970s, Libyan leader Colonel Muammar Qadhafi has sought to obtain weapons of mass destruction (WMD), particularly chemical and biological weapons (CBW). By the late 1980s, Libya had developed a rudimentary capability to produce such weapons. Western experts view the pursuit of CBW as a means of bolstering Libya’s military capability, since the country lacks effective conventional...

2011

Uncertainty about behavior: Uncertainty about behavior refers to uncertainty regarding the actions taken by others. Sometimes it is hard to know what other states are doing – in particular, if they are cooperating or defecting. Consider weapons of mass destruction. Whatever a state may say publicly, it is very difficult for others to ascertain whether it is pursuing technologies associated with...

Journal: :محیط شناسی 0
لعبت زبردست دانشجوی دکتری برنامه ریزی محیط زیست، دانشکدة محیط زیست، دانشگاه تهران احمدرضا یاوری استادیار دانشکده محیط زیست دانشگاه تهران(ارزیابی و اکولوژی کوهستان) اسماعیل صالحی گروه مدیریت و برنامه ریزی دانشکدة محیط زیست دانشگاه تهران، دکتری شهرسازی مجید مخدوم استاد محیط زیست دانشکدة منابع طبیعی، دانشگاه تهران

fragmentation is one of the major spatial processes leading to change in a landscape, which is described as transformation of a specific habitat or land cover to smaller patches with less connectivity and viability. construction of roads is one of the main causes of fragmentation in natural areas and habitats. presence of roads in ecologically sensitive and protected areas, leads to destruction...

Journal: :Biodiversity and Conservation 2021

Abstract Tropical forests suffer severe habitat destruction. Thus, tropical frequently consist today of only a few small remnants that are often embedded within matrix agricultural fields and tree plantations. Forest specialist species have experienced population declines under these circumstances. We studied bird communities based on census plots set up in near-natural forest block, as well de...

Journal: رستنیها 2019

Cyanobacteria represent a small taxonomic group of photosynthetic prokaryotes which some of them are capable of N2 fixation and also possess a tremendous potential for producing a wide range of secondary metabolites. It has been suggested that, some of these microorganisms, especially heterocystous cyanobacteria, assist higher plant growth by supplying growth stimulating substances. During a fl...

2010
Jeremy T. Lundholm Paul J. Richardson

1. Current views of anthropogenic environments emphasize the extreme novelty of urban and industrial ecosystems. Proponents of reconciliation ecology argue that we need to use such habitats to conserve biodiversity, given the inadequacy of natural reserve systems. 2. Some of the harshest anthropogenic ecosystems may be able to support indigenous biodiversity due to their structural or functiona...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شهید چمران اهواز - دانشکده مهندسی علوم آب 1393

drought is transient phenomenon , slow , repetitive and integral part of the climate of each region. drought begins with a substantial reduction in precipitation over the long-term average rainfall and over time, reduced soil moisture and surface and ground water resources will continue to decrease. this phenomenon is the most important in bakhtegan basin because of its importance in strategic ...

Extended Abstract Introduction: Schrophularia striata is one of the medicinal plants of the Scrophulariaceae family and contains phenolic compounds. Locals have traditionally used this herbal medicine to treat infections caused by wounds, gastrointestinal diseases, and eye diseases. Due to excessive consumption by indigenous people and climate change, especially increasing temperature, the col...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2012
Benoit Guénard Michael D Weiser Robert R Dunn

Most of the described and probably undescribed species on Earth are insects. Global models of species diversity rarely focus on insects and none attempt to address unknown, undescribed diversity. We assembled a database representing about 13,000 records for ant generic distribution from over 350 regions that cover much of the globe. Based on two models of diversity and endemicity, we identified...

Journal: :BIO web of conferences 2023

This article examines the impact of catastrophic factors on ecology Earth. Natural cataclysms geophysical, geological, hydrological, atmospheric and other origin, can have a devastating effect human life, its economic activity, as well entire ecological system. Disturbances landscape environment, affect conditions. They lead to destruction flora fauna, redistribution water reserves, animal habi...

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