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151.
MIS与 GIS结合应用于生态定位研究是一个较好的具有扩展性的解决生态数据量大、统计繁琐的解决方案 ,能实现生态定位研究的管理规范化、现代化、自动化和网络化 ,更好地为生态系统定位研究服务 .阐述了会同生态定位研究站信息管理系统的设计和开发过程 ,介绍了系统的结构和功能 ,并对地理信息系统应用于生态定位研究作了一定的探讨 相似文献
152.
Ian Jeffreys 《Small-Scale Forestry》2004,3(1):99-117
Small-scale farm forestry has the potential to offer many benefits both to landholders and the wider community. As with all
changes in land-use practices, there are associated benefits and costs and these are not uniformly distributed. They have
varying impacts on the different values, aspirations, goals and objectives that exist within the community. Furthermore, the
community does not consider these values, aspirations, goals and objectives of equal importance. The degree of concern can
vary from minor to high and overriding all other considerations. When evaluating farm forestry options it is necessary to
address all of these concerns. This paper examines the combined use compensatory and non-compensatory multi-criteria analyses
to evaluate forestry options, in a case study for the Darling Downs region of Queensland, Australia. These aggregation techniques
are found to be highly complementary and together provide a comprehensive analysis. The compensatory technique provides a
sound measure of overall performance of a forestry system, whereas the non-compensatory technique alerts decision-makers to
presence of particularly poor performance with respect to individual criteria. The compensatory technique used is simple and
understandable even for those with non-mathematical backgrounds. This analysis can identify and aid communication of the relative
benefits and costs, and trade-offs, between economic, environmental and social considerations. 相似文献
153.
FORESTAR:A decision—support system for multi—objective forest management in Northeast China 总被引:11,自引:0,他引:11
SHAOGuo-fan DAILi-min LIYing-shan LiuYong-min BAIGuang-xin 《林业研究》2003,14(2):141-145
Past monoculture forestry in China has contributed to countrywide ecological disasters and economic difficulties in forestry regions. China‘s new forestry programs, Natural Forest Conservation Program and Returning Farmlands to Forests Program, provide opportunities for ecosystem management of mountain forests in China. A decision support system, FORE-STAR, has been developed for better managing and protecting natural forests in Changbai Mountain area. It uses GIS-based forest inventory data at a scale of forestry bureau. The first version contains two sub-modules: forest operation and forest res-toration. Under each sub-module, users can compare several decision options and make optimal choices. It can help field for-esters, forest managers, and policy makers make multi-objective and consistent decisions in planning forest management at hierarchical administrative scales. 相似文献
154.
In order to meet the demands of modern, information-based society, higher education in natural resource management needs to be transformed. Enhanced mobility of students and staff, multi- and transdisciplinary approaches, as well as innovative educational approaches are called for. Moreover, the urban component needs to be better incorporated, as exemplified by the emerging field of urban forestry. This paper relates to the developments in higher education within the context of education on urban forests and urban trees in Europe. Presented here are the main findings of a comparative European study led by the Danish Forest and Landscape Research Institute within the framework of the EU-funded COST Action E12 'Urban Forests and Trees'. In order to obtain an overview of the status of higher education on urban forestry in Europe, 180 educational institutions in 28 countries were sent a questionnaire. Results show that urban forestry is an expanding element of European education, as urban elements are becom 相似文献
155.
KU Daping Bernie DELL. Research Institute of Tropical Forestry CAF Guangzhou China . Murdoch University. Perth. Australia 《中国林业科技(英文版)》2002,(1)
Eucalypts are very popular for revegetation in many parts of south China because of their capacity to tolerate degraded sites and unfertile soils,and their fast growth potential to coppice. This paper reviews a decade of field trials in china, undertaken as part of several bilateral researchprograms in plantation forestry, concerning the use of fertilizers, harvest residue management and inoculation with ectomycorrhizal fungi. One of the key questions addressed is whether the productivity of plantation eucalypts in south China can be increased to the world average by nutrient management across a rotation. 相似文献
156.
To derive optimal benefits from intercropping timber, farmers should make important initial decisions on tree species and
planting density with a good understanding of their tradeoffs. Complex and data-intensive models used by researchers should
be supplemented with simpler models based on easily measured parameters and easily understood competition functions. In experiments
in the Philippine uplands, growth parameters of three popular farm-forestry species (Eucalyptus deglupta, E. torelliana, and Paraserianthes falcataria) were measured, along with intercropped and non-intercropped yields of maize and vegetables. The commonly used forestry parameter
of stand basal area had a significant negative correlation with intercrop yields (as a percentage of non-intercropped yields).
The slope of the regression line differed between species; in this study, percent yield loss per unit stem basal area growth
was in the order E. deglupta > E. torelliana > P. falcataria. The relationship between stand basal area and intercrop-yield decline was tested on an independent data set from China.
Intercrop yields had significant negative correlations with stand basal area of Paulownia elongata. We propose that adaptive tree-screening trials evaluate competitiveness in addition to evaluating growth and mortality.
Stand basal area may be better suited to this task than more mechanistic indices such as leaf-area index as it is easy to
measure, calculate, and understand, and it may serve as a better index of total (aboveground + belowground) competition. Basal
area is also directly related to tree volume, and allows farmers to more easily evaluate the economic tradeoffs between tree
growth and intercrop-yield declines.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
157.
Carly Green Brian Tobin Michael O’Shea Edward P. Farrell Kenneth A. Byrne 《European Journal of Forest Research》2007,126(2):179-188
Reporting carbon (C) stocks in tree biomass (above- and belowground) to the United Nations Framework Convention on Climate
Change (UNFCCC) should be transparent and verifiable. The development of nationally specific data is considered ‘good practice’
to assist in meeting these reporting requirements. From this study, biomass functions were developed for estimating above-
and belowground C stock in a 19-year-old stand of Sitka spruce (Picea sitchensis (Bong) Carr.). Our estimates were then tested against current default values used for reporting in Ireland and literature
equations. Ten trees were destructively sampled to develop aboveground and tree component biomass equations. The roots were
excavated and a root:shoot (R) ratio developed to estimate belowground biomass. Application of the total aboveground biomass function yielded a C stock
estimate for the stand of 74 tonnes C ha−1, with an uncertainty of 7%. The R ratio was determined to be 0.23, with an uncertainty of 10%. The C stock estimate of the belowground biomass component was
then calculated to be 17 tonnes C ha−1, with an uncertainty of 12%. The equivalent C stock estimate from the biomass expansion factor (BEF) method, applying Ireland’s
currently reported default values for BEF (inclusive of belowground biomass), wood density and C concentration and methods
for estimating volume, was found to be 60 tonnes C ha−1, with an uncertainty of 26%. We found that volume tables, currently used for determining merchantable timber volume in Irish
forestry conditions, underestimated volume since they did not extend to the yield of the forest under investigation. Mean
stock values for belowground biomass compared well with that generated using published models. 相似文献
158.
Leaf-water potential and soil-water depletion of walnut mulched with polyethylene and intercropped with alfalfa in Central Italy 总被引:1,自引:0,他引:1
In Italy, new agroforestry cultural models could play an important role in the diffusion of plantation forestry timber species. We studied the stem growth rates and leaf water potentials () of common walnut (Juglans regia L.), and gravimetric soil moisture (DW) depletion during the third and fourth growing seasons in an agroforestry trial in central Italy. Since the establishment of experimental plots in 1992, walnut was intercropped with alfalfa (Medicago sativa L.), with or without polyethylene (PE) mulching along tree rows. By the end of the study period, the unmulched-intercropped walnut was almost 68% smaller in stem diameter and height than the sole-unmulched control, demonstrating walnuts sensitivity to alfalfa competition. The competitive effect of alfalfa on walnut stem growth was effectively controlled/reduced by PE mulching. Stem growth rates of mulched-intercropped walnut were always lower than the control, but much higher (ca. 235% in stem diameter and height) than those of unmulched-intercropped walnut. The higher field performance of mulched-intercropped walnut compared to the un- mulched-intercropped treatment was associated with higher soil moisture and predawn and midday values during the summers driest periods. The presence of PE mulching was also associated with lower levels of soil moisture during the early and late growing season, but this did not negatively affect walnut and growth rates. These results suggest that in the climatic conditions of central Italy, competition for soil moisture between young common walnut trees and alfalfa can be substantially lowered, but not completely eliminated, by PE mulching.This revised version was published online in November 2005 with corrections to the Cover Date. 相似文献
159.
根据吉林市自然、社会和经济条件,结合城市景观布局,对吉林市的城市林业生态网络体系建设和水资源保护提出了建设性的建议。 相似文献
160.
以永平县林业矢量数据为例,利用91卫图助手软件和ArcGIS软件,通过北京54坐标系矢量数据在各坐标系下叠加、坐标系转换参数的计算、矢量数据坐标系的转换等步骤,阐述实现矢量数据坐标系WGS84、北京54、西安80和国家2000坐标系相互转换的方法,以实现各类自然资源矢量数据的共享。 相似文献