tehran the capital city of iran, with a population of about 8 million and an area of over 700 km2 is one of the most polluted metropolises in the world. tehran is suffering from a tremendous reduction in its sink capacity for absorption and assimilation of pollution which is generally due to uncontrolled urban sprawl and failure in consideration of ecological aspects into regional land use plan...

Global declines in pollinators, associated with land-use change [1-6] and fragmentation [7-10], constitute a serious threat to crop production and biodiversity [11]. Models investigating impacts of habitat fragmentation on pollen flow have categorized landscapes simply in terms of habitat and nonhabitat. We show that pollen flow depends strongly on types of land use between habitat fragments. W...

Although studies on the relation between size and efficiency are ample, studies on the relation between size, fragmentation, and efficiency are limited. It is the purpose of this study in which a single-stage stochastic parametric approach is used. For this purpose production of wheat in Iran is a good case because wheat is the core commodity of the Iranian agricultural system which is dominate...

Because human land uses tend to expand over time, forests that share a high proportion of their borders with anthropogenic uses are at higher risk of further degradation than forests that share a high proportion of their borders with non-forest, natural land cover (e.g., wetland). Using 1-km advanced very high resolution radiometer (AVHRR) satellite-based land cover, we present a method to sepa...

Land use/land cover change has been attracting increasing attention in the field of global environmental change research because of its role in the social and ecological environment. To explore the ecological risk characteristics of land use change in the Poyang Lake Eco-economic Zone of China, an eco-risk index was established in this study by the combination of a landscape disturbance index w...

This article estimated the impacts of land fragmentation on production costs and input demands using panel data of Japanese rice farms┻ Empirical results reveal that fragmentation increases production costs and offsets economies of size┼ and that these impacts are strong especially for large size farms┻ This result implies that as the farm gets larger┼ emphasis should be switched from increasin...

Land cover (LC) and land use (LU) dynamics induced by human and natural processes play a major role in global as well as regional patterns of landscapes influencing biodiversity, hydrology, ecology and climate. Changes in LC features resulting in forest fragmentations have posed direct threats to biodiversity, endangering the sustainability of ecological goods and services. Habitat fragmentatio...

Habitat fragmentation studies have produced complex results that are challenging to synthesize. Inconsistencies among studies may result from variation in the choice of landscape metrics and response variables, which is often compounded by a lack of key statistical or methodological information. Collating primary datasets on biodiversity responses to fragmentation in a consistent and flexible d...

This study examined the effect of urbanization on agricultural production in Abia State. Specifically, it categorized the land tenancy status of the farmers, analyzed the effect of urbanization on agricultural productivity and identified the constraints to agricultural productivity. Multistage random sampling technique was used to select the respondents. Primary data collected using structured ...