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Farming the planet: 1. Geographic distribution of global agricultural lands in the year 2000

Peer-reviewed publication
июля, 2008
Global

Agricultural activities have dramatically altered our planet's land surface. To understand the extent and spatial distribution of these changes, we have developed a new global data set of croplands and pastures circa 2000 by combining agricultural inventory data and satellite-derived land cover data. The agricultural inventory data, with much greater spatial detail than previously available, is used to train a land cover classification data set obtained by merging two different satellite-derived products (Boston University's MODIS-derived land cover product and the GLC2000 data set).

riverscape of Western Amazonia - a quantitative approach to the fluvial biogeography of the region

Journal Articles & Books
декабря, 2007
Ecuador
Bolivia
Brazil
Venezuela
Colombia
Peru

To provide a quantitative spatial analysis of the riverscape (open-water bodies and their surrounding areas) of the Western Amazonian lowlands using a consistent surface of remotely sensed imagery. Taking into account the essential significance of fluvial environments for the Amazonian biota, we propose that an enhanced understanding of the Amazonian riverscape will provide new insight for biogeographical studies in the region and contribute to the understanding of these megadiverse tropical lowlands.

Land use and land cover variation and soil properties of Cankırı-Eldivan Karataşbağı river basin

Policy Papers & Briefs
декабря, 2007
Turkey

The main objective of this study was to investigate changing of land uses and land covers and to compare current conditions of the basin with project results that were performed in 1961-2006 and to determine some soil properties of the basin. Stand relating to 1995 and 2006, geological and topographical maps and climatic data were used in this study. According to results, while forest area covered 14.5 % of the total area in 1955 was increased (35.8 %), degraded coppice, degraded blackpine and agricultural lands were decreased 5.7, 1.8 and 15.8% respectively.

Effects of stream map resolution on measures of riparian buffer distribution and nutrient retention potential

Journal Articles & Books
декабря, 2007

Riparian ecosystems are interfaces between aquatic and terrestrial environments recognized for their nutrient interception potential in agricultural landscapes. Stream network maps from a broad range of map resolutions have been employed in watershed studies of riparian areas. However, map resolution may affect important attributes of riparian buffers, such as the connectivity between source lands and small stream channels missing in coarse resolution maps.

Linking Land-use, Water Body Type and Water Quality in Southern New Zealand

Journal Articles & Books
декабря, 2007
New Zealand

Land-use and vegetation cover have been linked to the nutrient levels (nitrogen, phosphorus) of surface waters in several countries. However, the links generally relate to streams and rivers, or to specific types of standing water, for example shallow lakes in a geologically defined region.

Tracking the effects of one century of habitat lossand fragmentation on calcareous grassland butterfly communities

Journal Articles & Books
декабря, 2007
Belgium
Europe

Habitat loss and fragmentation are known to reduce patch sizes and increase their isolation, consequently leading to modifications in species richness and community structure. Calcareous grasslands are among the richest ecosystems in Europe for insect species. About 10% (1,150 ha) of the total area of a calcareous ridge region (Calestienne, Belgium) and its butterfly community was analysed over a timeframe of about 100 years.

Challenges to estimating carbon emissions from tropical deforestation

Journal Articles & Books
декабря, 2007

An accurate estimate of carbon fluxes associated with tropical deforestation from the last two decades is needed to balance the global carbon budget. Several studies have already estimated carbon emissions from tropical deforestation, but the estimates vary greatly and are difficult to compare due to differences in data sources, assumptions, and methodologies. In this paper, we review the different estimates and datasets, and the various challenges associated with comparing them and with accurately estimating carbon emissions from deforestation.

Differences in land cover interpretation in landscapes rich in cover gradients: reflections based on the montado of South Portugal

Journal Articles & Books
декабря, 2007
Portugal

This paper contributes to the discussion on current issues in methodologies of mapping land cover in the agro-silvo-pastoral landscapes of the Mediterranean. These landscapes, characterized by intermixed land use and indefinite boundaries, require particular attention in applying the patch-corridor-matrix model when classifying patches and their delineation. In a case study area in southeast Portugal, mainly characterized by agro-silvo pastoral systems, the land cover for 1990 has been mapped.

Assessing the effects of land use and land cover patterns on thermal conditions using landscape metrics in city of Indianapolis, United States

Journal Articles & Books
декабря, 2007
United States of America

Direct applications of remote sensing thermal infrared (TIR) data in landscape ecological research are rare due to limitations in the sensors, calibration, and difficulty in interpretation. Currently there is a general lack of methodology for examining the relationship between land surface temperatures (LST) derived from TIR data and landscape patterns extracted from optical sensors. A separation of landscapes into values directly related to their scale and signature is a key step.

Gypsy moth response to landscape structure differs from neutral model predictions: implications for invasion monitoring

Journal Articles & Books
декабря, 2007

Simulations of dispersal across computer-generated neutral landscapes have generated testable predictions about the relationship between dispersal success and landscape structure. Models predict a threshold response in dispersal success with increasing habitat fragmentation. A threshold is defined as an abrupt, disproportionate decline in dispersal success at a certain proportion of habitat in the landscape.

regression tree-based method for integrating land-cover and land-use data collected at multiple scales

Journal Articles & Books
декабря, 2007

As data sets of multiple types and scales proliferate, it will be increasingly important to be able to flexibly combine them in ways that retain relevant information. A case in point is Amazonia, a large, data-poor region where most whole-basin data sets are limited to understanding land cover interpreted through a variety of remote sensing techniques and sensors. A growing body of work, however, indicates that the future state of much of Amazonia depends on the land use to which converted areas are put, but land use in the tropics is difficult to assess from remotely sensed data alone.

Tracking environmental dynamics and agricultural intensification in southern Mali

Journal Articles & Books
декабря, 2007
Mali

The Office de la Haute Vallée du Fleuve Niger (OHVN) zone in southern Mali is a small but important agricultural production region. Against a background of environmental degradation including decades of declining rainfall, soil erosion, and human pressure on forest resources, numerous farming communities stand out through the use of improved soil and water management practices that have improved agricultural and environmental conditions. Field surveys conducted in 1998-2001 indicated that environmental and agricultural conditions have improved in the past decade.