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451.
Robert J. Zomer Antonio Trabucco Louis V. Verchot Bart Muys 《Mitigation and Adaptation Strategies for Global Change》2008,13(3):219-239
Within the United Nations Framework Convention on Climate Change (UNFCCC) Kyoto Protocol, countries have significant latitude
to define a forest. The most important parameter affecting area designated as forest is the minimum crown cover which can
be set between 10 and 30%. The choice will have implications for the amount of land available in a country for afforestation
and reforestation activities within the Clean Development Mechanism (CDM-AR). In this paper, we present an analysis of the
regional differences in land availability for CDM-AR projects. We then examine how the choice of a high or low threshold value
for crown cover will affect the area available for CDM activities and how the limitations imposed by this element of the definition
compares to other factors that are likely to limit CDM activities. Results represent a global analysis that included all countries
not included in Annex I of the Kyoto Protocol, and examined the effect on land availability of a range of crown cover thresholds
ranging from 10–30%. Of the 140 Non-Annex One countries, 107 countries were found to have a potential for CDM-AR projects.
Asia had the largest amount of combined area suitable for CDM-AR at the 10% crown cover threshold level. However, at 30%,
South America had the greatest amount of land available, and a large change in available land area, which increased by almost
five times compared to what was available at the 10% threshold. The area available in Africa increased by a factor of 5.5.
Central America showed the largest increase, to almost 10 times more at the 30% threshold. By contrast, within Asia, the area
increase was comparatively less, but still the area nearly doubled. Globally, a low threshold of 10% crown cover excluded
almost 2/3 of the land identified that was eligible at 30%, over 5 million km2. The spatial analyses showed not only the effects of the choice of the crown cover criterion, but also where the land was
available for CDM activities within each country at different thresholds. Protected areas account for 10–20% of the CDM-AR
eligible area in most countries. 相似文献
452.
ABSTRACT Between 1992 and 2015 Argentina lost 17% of its tree cover. Regionally, deforestation continues, but net forest loss recently came to a halt. Some scholars argue that this was facilitated by industrial agricultural intensification. This view is debated, but we focus on the neglected costs associated with this intensification. An almost tenfold increase of pesticide use in Argentina during the last two decades caused the pollution of soil, water and sediments. The widespread use of pesticides is impairing the health of agricultural workers and people living near agricultural fields, and is putting the health of vulnerable parts of the population (children and pregnant women) at risk. More than 50 pesticide active ingredients marketed in Argentina have been banned in the European Union for safety reasons. We contend that health and pollution aspects need to be taken into account when assessing the benefits and drawbacks of different types of land use. 相似文献
453.
H. Doing 《Journal of Coastal Conservation》1995,1(2):145-172
This paper is a summary and elaboration of an earlier publication in Dutch on the compilation of a landscape-ecological map,
scale 1 : 50 000, of the Dutch coast. It is argued that such an integrated map is the best basis for the conservation and
management of the coastal dunes and salt marshes. It may be combined with local more detailed vegetation maps, some examples
of which are mentioned in the context of management.
The Dutch North Sea coast is a ca. 350 km long chain of sandy beaches and sand dunes, from only 100 m to more than 10 km wide.
On sheltered stretches of dune coasts along estuaries in the Southwest and on the Wadden Sea islands, salt marshes have developed.
The small-scale gradient structure of the beach-dune-salt marsh complex is emphasized. 相似文献
454.
探讨许昌市地面沉降的原因及其对策 总被引:1,自引:0,他引:1
许昌市地表水资源严重短缺,为了供水的需要,该市掠夺性地开采地下水,造成地下水水位急骤下降,市区大面积地面沉降,已出现地裂现象.提出要合理地使用地下水资源、限制超量开采、开源节流,补充地下水源等措施,使地下水位逐渐回升,防止该市地面继续沉降而产生的不可挽回的后果. 相似文献
455.
456.
Ariane de Bremond 《Ambio》2021,50(7):1299
This perspective recognizes the seminal Ambio articles of Sombroek et al. (1993), Turner et al. (1994) and Brussaard et al. (1997), identifying their individual and collective role in laying the ground work for a global change research agenda on land and its human use through increased understanding of terrestrial ecosystem dynamics and global change, and furthering nascent interdisciplinary efforts within the global change science community to better understand the ‘human driving forces’ of change. From these efforts, land system science, as a systemic science focused on complex socio-ecological interactions around land use and associated trade-offs and synergies, emerges as an ‘interdiscipline’ challenged to better understand land systems as the ‘meeting ground’ for multiple claims on land for biodiversity, carbon, livelihoods, food production among others, and support pathways to sustainability for people and nature. 相似文献
457.
N. Farella R. Davidson M. Lucotte S. Daigle 《Agriculture, ecosystems & environment》2007,120(2-4):449-462
In the Brazilian Amazon, colonization is modifying the landscape at an exceedingly fast pace. Recently established households practice slash-and-burn agriculture and participate in the overall deforestation of the Amazon. Near the Transamazon highway, these family agricultural practices are the main cause of deforestation. The study presented here is oriented toward a better understanding of the impacts of farming practices on soil chemical composition. This study used a sampling design based on soil samples taken on farm plots, which had been submitted to a wide range of spatial and temporal sequential land-uses, including soils that were only recently denuded. The data shows that soil responses (organic matter (OM) content, fertility and mercury (Hg) retention) to these varied land-uses were relatively similar, suggesting that the most important event determining the responses was deforestation itself. This is well illustrated by the Hg content of soils, which changed immediately after deforestation and then only slightly thereafter. This phenomenon could also be seen in the base cation (calcium (Ca), potassium (K) and magnesium (Mg)) content which rose drastically after deforestation and tended to stay high for a period up to 10 years of cropping and pasture. This lasting cation rise is reflected by ammonium (NH4) displacement from surface soils. Indeed, inorganic nitrogen (N) is the most important nutrient loss upon deforestation. Nonetheless, when time spent in fallow was greater than 15 years, base cations (Ca, Mg, K), available N and phosphorus (P) contents tended to go back to initial forest soil values and in some cases to exceed them. Soil type was seen to mediate responses to land-use. Clay-sandy soils showed a lower content of available N and carbon (C) than clayey soils at the soil surface, a difference that was accentuated by deforestation. Conversely, the higher initial content of Hg in clayey soils was associated with a more important Hg loss from the soil's surface. By shedding light on the consequences of family practices for OM, nutrient status and Hg depletion, this paper gives a new perspective on soil responses to agricultural practices. These conclusions need to be addressed in a strategy plan to limit family land-use impacts on soils and the surrounding ecosystems. Recommendations for more sustainable land uses are proposed based on what has been learned about soil responses to local agricultural practices. 相似文献
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