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1.
生态土地分类及其在林业上的应用前景 总被引：4，自引：0，他引：4
生态土地分类是随着景观生态学的进展与土地调查工作的开展而发展到世界规模的。生态土地分类的基本原理是,把土地视为一个景观,而景观无论在其各种属性之间,也无论在其各种要素之间,是相互作用的。生态土地分类的基本特点是对地域空间实体的区分,随着类等级由上向下,所划分的与一定比例尺相联系的土地单元在地域上越来越小。当前各国的生态土地分类的级别体系有向统一化和多级化的发展趋势。基于在河北省平山县卸甲河流域的个例研究,我们提出的分类系统包括三级,即土地系统、土地组合和土地类型,并分别对每一级给出相应的定义、评定标准和命名原则。在该流域的范围内,划分了８个土地系统,对于每一个系统分别划分了若干个土地组合和土地类型。 相似文献
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Stephen G. Perz 《Agroforestry Systems》2005,63(3):263-279
This paper focuses on agricultural diversity, a key property of agroforestry systems, and examines the influences of household
asset endowments. The analysis addresses a debate between ‘differential motivation’ and ‘ differential capacity’ arguments
concerning the importance of asset inequality for agricultural diversification among rural households in developing regions.
I draw on data from a survey of small farm colonists in the Brazilian Amazon to assess components and measures of agricultural
diversity, and to model those diversity measures using indicators of household asset endowments. The results indicate that
agricultural diversification is modest in the study site, but varies among households, as do asset endowments. Models of agricultural
production and income diversity indicate that agricultural diversity primarily reflects labor endowments, though certain types
of capital are also important. These findings bear implications for research on agricultural diversity in other contexts,
and for policies aiming to promote ‘productive conservation’ by compatibilizing poverty reduction, economic development and
environmental sustainability. 相似文献
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呼伦贝尔沙地研究综述 总被引：1，自引：1，他引：0
从呼伦贝尔沙地形成、演化、沙物质来源以及现代沙漠化特征和植被恢复技术等方面综合论述了呼伦贝尔沙地研究的现状及其治理对策等问题,认为实现呼伦贝尔沙地的逆转还需要相当长的时间和努力。 相似文献
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Conversion of native forest ecosystem to cropland has considerably degraded the soil nutrient levels in the Bale Mountains, south-eastern highlands of Ethiopia. This study investigated the effects of land use change through conversion of native forest to cropland and/or grazing land on soil pH (H2O), base cations (Ca2+, Mg2+, K+, Na+), CEC and percentage base saturation (PBS) in three adjacent land-use types: cropland, grazing land and native forest. A total of 108 soil samples (3 replications × 3 land-use types × 4 profiles × 3 soil depth layers, 0–0.2, 0.2–0.4 and 0.4–1.0 m) were collected for laboratory analyses. Results showed that soil pH, Na+ and K+, CEC, and PBS varied significantly with respect to land use and soil depth while Ca2+and Mg2+ varied with soil depth (ρ < 0.05). Conversion of native forest ecosystem to cropland during a 15-year period significantly increased soil pH and PBS while reducing Na+ and K+. The CEC in the cropland was reduced by 37.7% (2.6% per annum) compared to the native forest, which could be attributed to the decline in organic matter concentrations. If such rapid declines in soil nutrient concentrations continue unabated, the soils will reach at the point of no return within a few decades. Although the effect of grazing on most of the properties was found to be minimal, adapting the number of stock to the carrying capacity of the land and thereby enhancing the natural regeneration, combined with proper cropland management practices could help restoring soil nutrients for sustainable agricultural production and ecosystem functions. 相似文献
6.
Sibylle K. Hassler Beate Zimmermann Michiel van BreugelJefferson S. Hall Helmut Elsenbeer 《Forest Ecology and Management》2011,261(10):1634-1642
Landscapes in the humid tropics are undergoing a continuous change in land use. Deforestation is still taking its toll on forested areas, but at the same time more and more secondary forests emerge where formerly agricultural lands and pastures are being abandoned. Regarding soil hydrology, the extent to which secondary succession can recover soil hydrological properties disturbed by antecedent deforestation and pasture use is yet poorly understood. We investigated the effect of secondary succession on saturated hydraulic conductivity (Ks) at two soil depths (0-6 and 6-12 cm) using a space-for-time approach in a landscape mosaic in central Panama. The following four land-use classes were studied: pasture (P), secondary forest of 5-8 years of age (SF5), secondary forest of 12-15 years of age (SF12) and secondary forest of more than 100 years of age (SF100), each replicated altogether four times in different micro-catchments across the study region. The hydrological implications of differences in Ks in response to land-use change with land use, especially regarding overland flow generation, were assessed via comparisons with rainfall intensities.Recovery of Ks could be detected in the 0-6 cm depth after 12 years of secondary succession: P and SF5 held similar Ks values, but differed significantly (α = 0.05) from SF12 and SF100 which in turn were indistinguishable. Variability within the land cover classes was large but, due to sufficient replication in the study, Ks recovery could be detected nonetheless. Ks in the 6-12 cm depth did not show any differences between the land cover classes; only Ks of the uppermost soil layer was affected by land-use changes. Overland flow - as inferred from comparisons of Ks with rainfall intensities - is more likely on P and SF5 sites compared to SF12 and SF100 for the upper sample depth; however, generally low values at the 6-12 cm depth are likely to impede vertical percolation during high rainfall intensities regardless of land use.We conclude that Ks can recover from pasture use under secondary succession up to pre-pasture levels, but the process may take more than 8 years. In order to gain comprehensive understanding of Ks change with land use and its hydrological implications, more studies with detailed land-use histories and combined measurements of Ks, overland flow, precipitation and throughfall are essential. 相似文献
7.
人工林地力衰退研究现状与进展 总被引：3，自引：0，他引：3
介绍了国内外人工林地力衰退的历史背景和现状,从人工林群落结构、土壤微生物种群区系、土壤理化性质和生化特性,栽培措施等方面分析了导致人工林地力衰退的原因,提出了调整林分结构,保护林下植被、混交,林地施肥和土壤改良、科学营林等措施防止地力衰退;概述了人工林地力衰退的研究进展和今后研究方向。 相似文献
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J. Gordon ArbuckleJr. Corinne Valdivia Andrew Raedeke John Green J. Sanford Rikoon 《Agroforestry Systems》2009,75(1):73-82
Land tenure has long been considered a critical factor in determining the adoption and long-term maintenance of agroforestry
practices. Empirical evidence from non-US settings has consistently shown that secure land tenure is positively associated
with agroforestry adoption. In the US, over 40% of private agricultural land is farmed by someone other than the owner. Given
the importance of land tenure in agroforestry decisions in other countries and the magnitude of non-operator landownership
in the US, there has been surprisingly little focus on land tenure in the temperate agroforestry literature. Using data from
a 1999 survey in Missouri, this study explores factors associated with non-operator landowner interest in agroforestry. Results
suggest that differences in farming orientation are linked to interest in agroforestry. Closer ties to farming, stronger financial
motivations for landownership, and higher proportion of land planted to row crops were negatively related to interest in agroforestry
among non-operator landowners. Environmental or recreational motivations for landownership and contacts with natural resource
professionals were positively associated with interest in agroforestry. These results, consistent with earlier qualitative
research suggesting that farm operators who have a strong “conventional farming identity” were less interested in agroforestry,
point to a divide between landowners for whom environmental and recreational values play an important role in ownership motivation
and those for whom financial considerations take precedence. The findings imply that agroforestry development programs in
the US should take non-operator landowners and their farming and ownership orientations into account when designing research
and outreach efforts.
相似文献
| J. Gordon Arbuckle Jr.Email: |
10.
LI Weichang DENG HuafengResearch Institute of Forestry Policy Information. Chinese Academy of Forestry. Beijing . China eiiine Forestrv Universuty. Beiiine . China 《中国林业科技(英文版)》2003,(4)
Application of participatory approaches in governmental forestry projects is a bran-new forestry design method. The purpose is to plan the utilization of land correctly, and to determine planting sites, planting species, participating households and management models, based on the projects' requirements and the farmers' demands. Participatory approaches are now practiced in some of the counties in Land Conversion Project. The paper presents the significance and necessity of practicing community mechanism and participatory approach in governmental forestry projects. The author consider that in case the participatory approach of community forestry is widely applied in the governmental forestry projects and activities, the enthusiasm of rural communities and farmers to plant and to protect forest will be inspired, and it is an undoubted drive to sustainable utilization of forest resources. The author also discusses the possibility of applying participatory approaches in the planning stage of Land Conversio 相似文献
11.
摸清自然保护区的土地利用现状,可以更好地加强自然保护区的建设和管理。文章通过对四川省林业自然保护区的土地利用状况进行分析统计,对自然保护区监测管理工作提出了优化合理布局、完善功能区划、减少人为影响、提高林地质量和加大保护力度等建议。 相似文献
12.
竹林等不同治理模式下坡耕地的土壤水分物理性质特征研究 总被引：1，自引：0，他引：1
通过对坡耕地竹园、茶园、柑橘、板栗和板栗退耕等5种不同治理模式的土壤水分物理性质的特征进行定位研究,研究表明:(1)枝叶繁茂的竹林的土壤容重小于茶园、板栗林间作、板栗退耕和柑橘林等林地相应土层的容重。并且各区土壤容重也都呈现出随土层深度的增加,土壤容重增大的趋势。(2)各试验模式土壤孔隙度和土壤非毛管孔隙度均表现出随土壤深度的增加而逐渐降低的趋势,但板栗间作模式的土壤孔隙度则表现为随土壤深度的增加而增加的变化动态。(3)土壤的含水量的变化与月降雨量的分配情况有明显的正相关关系,降雨量大的月份其土壤含水量就高,降雨量少的月份其土壤含水量就相对较低。(4)同一种林型0~60 cm土层范围内土壤含水量随土壤深度的增加而增加,竹园的土壤含水量明显高于其它类型林地的土壤含水量。 相似文献
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土地利用方式对土壤团聚体组成及质量的影响 总被引：6，自引：0，他引：6
分析了福建省建瓯市土地利用方式对土壤团聚体组成及水稳性的影响,结果表明,林地有利于形成大粒径土壤团聚体,而柑橘园、茶园、坡耕地形成的土壤团聚体粒径较小。不同土地利用方式对土壤团聚体的质量有较大影响:>2 mm水稳性土壤团聚体含量和土壤团聚体平均重量直径的顺序都为:木荷林>封育林>杉木林>柑橘园>茶园>坡耕地。平均重量直径与>0.25 mm水稳性土壤团聚体含量存在极显著的线性正相关关系。 相似文献
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移动GIS在土地变更调查中的应用 总被引：5，自引：0，他引：5
以西南林学院为试验区,以Trimble GeoXT为移动GIS的移动设备,实现了野外空间数据的实时采集和对历史数据的编辑和更新;通过后处理差分处理,实现了土地变更信息的亚米级精度.研究结果表明,移动GIS较之于传统方法在信息收集与更新数据方面有很大的优势,在以后国家的土地详查中值得研究与推广. 相似文献
17.
This paper analyses the first 5 years of the implementation of the Conservation Use Valuation (CUV) program in Georgia. This program provides for current use tax assessment for land dedicated to selected uses for a period of 10 years. Using a sample of counties from the north Georgia region where the program has been most heavily utilized, we analyze the economic and land use impacts of the program. We show that while there is substantial variability in enrollment across counties, the average land area per enrolled covenant is 27.6 ha. If we use this average value for the entire region, then over 22% of the eligible land in north Georgia is currently enrolled in the program. The fiscal impacts are also varied, with some counties showing a substantial reduction in property tax revenues while others showed only a marginal impact. 相似文献
18.
Mt. Kilimanjaro area with the old Chagga agroforestry system has been one of the most productive agricultural areas is Tanzania.
Today the area is facing several challenges that affect people’s livelihoods. To study implications of low coffee price, population
pressure and ensuing land use change on the farming systems and livelihoods of the people of the southern slopes of Mt. Kilimanjaro,
Tanzania, an interview survey was conducted. A multivariate regression analysis was used in studying and testing the interrelationships
between farm production and some socio-economic variables (assets). From nine different independent variables only land size
and farmers age had statistically significant influence on revenue from the main crops grown. This suggests that families
have so many different combinations of assets and farm-specific temporally varying strategies and objectives that it is not
possible to find clear patterns of assets and strategies that would lead to successful livelihood outcomes. Due to sinking
coffee prices in the world market, farmers have been looking for alternatives to earn cash. As land scarcity hinders both
expansion of cultivation and expansion of animal keeping, more intensified and diversified production and off-farm activities
have become crucial. There is an urgent need for technical research and experimentation on new agricultural options for the
area and a need of understanding and creation of marketing channels. 相似文献
19.
发育林下植被是恢复杉木人工林地力的重要途径 总被引：70，自引：5，他引：70
论述我国中亚热带杉木盛产区，通过间伐发育林下植被，改良土壤理，化性质，提高森林土壤生物活性，从而为通过合理的森林经营，发育林下植物群落，维护和提高森林土壤肥力，改良杉木人工林地力衰退，提供可靠的科学数据和途径。 相似文献
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以保山市杨柳小流域1994年的森林资源二类调查数据为基础。利用2004年Aster卫星遥感图像为信息源。结合地面调查。获取了森林资源扣土地利用的现状图。通过GIS的空间叠加分析得出土地利用10年间的空间变化信息。结合地形因子提出坡度25°以上的坡耕地进行退耕还林，并对小流域做作出初步的治理决策分析。为杨柳小流域的合理规划扣治理提供了详实的基础数据。 相似文献