نتایج جستجو برای: population growth and climate changes

تعداد نتایج: 17112870  

Journal: :محیط شناسی 0
منصور زیبایی آذر شیخ زین الدین

in this study an attempt has been made to empirically examine the relationship between biodiversity and economic growth using indicators of species diversity and income per capita as proxies for biodiversity and economic growth, respectively.also the effects of agricultural value added as a percentage of gdp, trade freedom index, exchange rate, population, percantage of land developed for agric...

2016
Ana Ruiz‐Navarro Phillipa K. Gillingham J. Robert Britton

Predictions of species responses to climate change often focus on distribution shifts, although responses can also include shifts in body sizes and population demographics. Here, shifts in the distributional ranges ('climate space'), body sizes (as maximum theoretical body sizes, L∞) and growth rates (as rate at which L∞ is reached, K) were predicted for five fishes of the Cyprinidae family in ...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2010
Derek M Johnson Ulf Büntgen David C Frank Kyrre Kausrud Kyle J Haynes Andrew M Liebhold Jan Esper Nils Chr Stenseth

Climate change has been identified as a causal factor for diverse ecological changes worldwide. Warming trends over the last couple of decades have coincided with the collapse of long-term population cycles in a broad range of taxa, although causal mechanisms are not well-understood. Larch budmoth (LBM) population dynamics across the European Alps, a classic example of regular outbreaks, inexpl...

The present study aims to investigate the structure and trend of climate parameters affecting grape growth in Khorasan Razavi (north eastern Iran) in the period of 1991-2015 in 8 weather stations. Effective climate elements such as temperature, precipitation, the number of hot days, the number of frost days, sunshine hours and parameters such as maximum temperature, annualaverageannual average ...

2015
Elvire Bestion Aimeric Teyssier Murielle Richard Jean Clobert Julien Cote Georgina M Mace

Evidence has accumulated in recent decades on the drastic impact of climate change on biodiversity. Warming temperatures have induced changes in species physiology, phenology, and have decreased body size. Such modifications can impact population dynamics and could lead to changes in life cycle and demography. More specifically, conceptual frameworks predict that global warming will severely th...

2017

Providing nutritious and environmentally sustainable food to all people at all times is one of the greatest challenges currently facing society. This problem is particularly acute in Africa where an estimated one in four people still lack adequate food to sustain an active and healthy life. In this study, we consider the potential impact of future population growth and climate change on food se...

Journal: :مرتع و آبخیزداری 0
مهدی قربانی دانشجوی دکتری مرتعداری، دانشکده منابع طبیعی، دانشگاه تهران، ایران علی اکبر مهرابی استاد دانشکده منابع طبیعی، دانشگاه تهران، ایران محمدرضا ثروتی دانشیار دانشگاه شهید بهشتی، ایران علی اکبر نظری سامانی استادیار دانشکده منابع طبیعی، دانشگاه تهران، ایران

nowadays, population growth and on the other hand resources limitations astonish authorities. population changes cause variation in economic activities and land use changes. as a whole, overusing, improper land use and human disturbances over natural resources make environmental imbalances worse. in recent decades, we have seen land use changes in taleghan basin. land use changes were produced ...

Journal: :توسعه کارآفرینی 0
محمد رضا اکبری دانشجوی دکتری کشاورزی دانشگاه تهران احمد رضوانفر استاد گروه ترویج و آموزش کشاورزی، دانشکده اقتصاد و توسعه کشاورزی، پردیس کشاورزی و منابع طبیعی دانشگاه تهران امیر علم بیگی استادیار گروه ترویج و آموزش کشاورزی، دانشکده اقتصاد و توسعه کشاورزی، پردیس کشاورزی و منابع طبیعی دانشگاه تهران

the agricultural sector was affected by climate change more than every other sectors, because it is close to nature. in other words, the effects of climate change were been on the farmers’ livelihood. farmers need to entrepreneurial changes for adaptation to climate change in their livelihood. hence, investigation of farmers’ entrepreneurial behavior in response to climate change was the main p...

2017
Juliann E Aukema Narcisa G Pricope Gregory J Husak David Lopez-Carr

Humans and the ecosystem services they depend on are threatened by climate change. Places with high or growing human population as well as increasing climate variability, have a reduced ability to provide ecosystem services just as the need for these services is most critical. A spiral of vulnerability and ecosystem degradation often ensues in such places. We apply different global conservation...

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