检索结果-南通市图书馆

Evaluating the effect of plain afforestation project and future spatial suitability in Beijing

Science China Earth Sciences 2020年第10期63卷 1587-1598页

作者： Tengyun HU Xuecao LI Peng GONG Wencheng YU Xiaochun HUANG Beijing Municipal Institute of City Planning and Design Beijing 100045China Department of Geological and Atmospheric Sciences Iowa State UniversityAmes 50011USA Ministry of Education Key Laboratory of Earth System Modeling Department of Earth System ScienceTsinghua UniversityBeijing 100084China Tsinghua Urban Institute Tsinghua UniversityBeijing 100084China

Taking the"One Million-Mu(666 km^2)"Plain Afforestation(PhaseⅠ)Project(Phase I afforestation)in Beijing city as an example,we monitored the growth status of planted forest using long-term remote sensing images,and evaluated the impacts of afforestation on land use change and vegetation growth.We found there is a large space for improvement regarding the ecological benefits of the project.Moreover,we found forest patches with decreasing greenness after the afforestation were mainly converted from farmland with high greenness and low heterogeneity in terms of the normalized difference vegetation index(NDVI).This implies that those farmland patches are inappropriate for afforestation.According to the results from PhaseⅠafforestation and the impact of urbanization on green space,we constructed a series of spatial variables and generated a suitability map for the next"New Round of One Million-Mu(666 km^2)Afforestation project"(PhaseⅡafforestation).We then modeled the spatial distribution of PhaseⅡafforestation based on the derived suitability map.This study is crucial for the scientific evaluation of afforestation projects for space planning(e.g.,urban green space planning).The evaluation and modeling framework built in this study can be used to support the decision making and policy implementation of afforestation projects in China.

关键词： Urban land use Afforestation forest growth Suitability Segmentation forest modeling

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Estimating the productive potential of five natural forest types in northeastern China

引用

forest Ecosystems 2019年第4期6卷 274-284页

作者： Zhaofei Wu Zhonghui Zhang Juan Wang Research Center of forest Management Engineering of State forestry and Grassland Administration Beijing Forestry University

Background: There is a serious lack of experience regarding the productive potential of the natural forests in northeastern China, which severely limits the development of sustainable forest management strategies for this most important forest region in China. Accordingly, the objective of this study is to develop a first comprehensive system for estimating the wood production for the five dominant forest types.Methods: Based on a network of 384 field plots and using the state-space approach, we develop a system of dynamic stand models, for each of the five main forest types. Four models were developed and evaluated, including a base model and three extended models which include the effects of dominant height and climate variables. The four models were fitted, and their predictive strengths were tested, using the "seemingly unrelated regression"(SUR) technique.Results: All three of the extended models increased the accuracy of the predictions at varying degrees for the five major natural forest types of northeastern China. The inclusion of dominant height and two climate factors(precipitation and temperature) in the base model resulted in the best performance for all the forest types. On average, the root mean square values were reduced by 13.0% when compared with the base model.Conclusion: Both dominant height and climate factors were important variables in estimating forest production. This study not only presents a new method for estimating forest production for a large region, but also explains regional differences in the effect of site productivity and climate.

关键词： forest types forest growth Climate Site conditions Seemingly unrelated regression

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Quantifying the effect of persistent dryer climates on forest productivity and implications for forest planning:a case study in northern Germany

引用

forest Ecosystems 2018年第4期5卷 451-471页

作者： Matthias Albert Ralf-Volker Nagel Johannes Sutmoller Matthias Schmidt Department of forest growth Northwest German Forest Research Institute GottingenGermany Department of Environmental Control Northwest German Forest Research InstituteGottingenGermany.

Background: forest management decisions are based on expectations of future developments. For sound decisions it is essential to accurately predict the expected values in future developments and to account for their inherent uncertainty,for example the impact of climate change on forests. Changing climatic conditions affect forest productivity and alter the risk profile of forests and forest enterprises. Intensifying drought stress is seen as one major risk factor threatening forest management in the north German lowlands. Drought stress reduces tree growth and vitality and might even trigger mortality. But so far, it is not possible to quantify effects of a persistent dryer climate on forest productivity at a level suitable for forest management.Methods: We apply a well-established single-tree forest growth simulator to quantify the effect of persistent dryer climates on future forest productivity. We analyse the growth of Scots pine(Pinus sylvestris L.), European beech(Fagus sylvatico L.) and oak(Quercus robur L. and Quercus petraea(Matt.) Liebl.) in two forest regions in the north German lowlands for a time interval of 60 years until 2070. The growth response under three different climate projections is compared to a baseline scenario.Results: The results show clear differences in volume increment to persistent dryer climates between tree species. The findings exhibit regional differences and temporal trends. While mean annual increment at biological rotation age of Scots pine and oak predominantly benefits from the projected climate conditions until 2070, beech might suffer losses of up to 3 m^3·ha^(-1)yr^(-1) depending on climate scenario and region. However, in the projection period2051 to 2070 the uncertainty ranges comprise positive as well as negative climatic effects for all species.Conclusions: The projected changes in forest growth serve as quantitative contributions to provide decision support in the evaluation of, for example, species future site suitability and timber supply assessments. The analys

关键词： Climate change forest growth forest productivity Persistent dryer climate simulation study Uncertainty

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Impact of Natural forest Protection Program policies on forests in northeastern China

引用

forestry Studies in China 2011年第3期13卷 231-238页

作者： ZHANG Kun Yasuto HORI ZHOU Shao-zhou Tetsuya MICHINAKA Yuichiro HIRANO Satoshi TACHIBANA China National forestry Economics and Development Research Center State Forestry Administration Beijing 100714 P. R. China forestry and forest Products Research Institute 1 Matsunosato Tsukuba Ibaraki 305-8687 Japan

This study analyzes the effects of the Natural forest Protection Program （NFPP） on the restoration of forest resources in the northeastern forest region of China, an important region because of its ecological and geographical location and timber supply in China, by using panel data sets of 35 forest farms of state-owned forest enterprises. Panel data analysis results show that related policies under the NFPP have had positive effects on forest resources. Planting activity had a statistically significant effect on forest growth and could be reinforced continually by planting tree species suitable for a warming climate in temperate forests. forest management and protection played a powerful role in increasing the growing stock of the forests. In NFPP areas timber harvests, after implementation of the NFPP, were a positive factor in increasing forest resources if the harvests combined effective tending and thinning under a carefully guided management plan.

关键词： NFPP policy impact forest growth panel data analysis

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Strategies for Achieving Sustainable Logging Rate in the Brazilian Amazon forest

引用

Open Journal of forestry 2014年第2期4卷 100-105页

作者： Evaldo Munoz Braz Patricia Povoa de Mattos Mariana Ferraz Oliveira Renato Olivir Basso Embrapa forestry ColomboBrazil Universidade Federal do Paraná CuritibaBrazil Elabore Projetos e Consultoria Florestal SinopBrazil

Data of increment of the remnant trees after logging, ingrowth and mortality was obtained by assessment before logging and after 6 years, two sites of 50 ha, in Amazon forest. Logging scenarios were simulated to identify the logging rate potential for each studying site, by diameter class projection method. The cycle of 35 years and the logging rate of 30 m3.ha-1 exceed the time required for recovery in the primary forest, in the studied site. The simulation showed that in the studying area, a well-planned logging, with minimum logging damage would be possible to implement an initial cycle of 25 years to the forest to recover 30 m3.ha-1, if 50% of the timber stock were reserved. The forest increment, beyond important factors such as the increase of individual species, is quite dependent on the remnant trees.

关键词： Diametric Structure forest Regeneration Cut Cycle forest growth

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：