检索结果-南通市图书馆

Estimation of a basal area growth model for individual trees in uneven-aged caspian mixed species forests

Journal of Forestry Research 2018年第5期29卷 1205-1214页

作者： Zohreh Mohammadi Soleiman Mohammadi Limaei Peter Lohmander Leif Olsson Department of Forestry Faculty of Natural ResourcesUniversity of Guilan P.O. Box 1144 Sowmeh Sara Iran Optimal Solutions in Cooperation with Linnaeus University Umea Sweden Department of Information Systems and Technology Facultyof Sciences Technology and Media Mid Sweden UniversitySundsvall Sweden

The aim of this study was to estimate a basal area growth model for individual trees in uneven-aged caspian forests.A survey was conducted in order to find a natural forest without any harvesting activities,a so called ＇untouched forest＇ and an area was selected from the Iranian caspian *** sample plots in the same aspect and of the same forest type were *** each plot,total tree height,diameter at breast height,distance of neighbor trees and azimuth were *** trees were selected and drilled with increment borer to determine the increment *** analysis was used to estimate the growth *** show that,for individual trees,there is a significant nonlinear relationship between the annual basal area increment,as the dependent variable,and the basal *** results also show that the basal area of competing trees has a positive influence on *** the increment is higher with more competing neighboring trees is possibly because plots with higher volume per hectare and more competition,most likely also have higher site index or better soil or better site productivity than the plot with lower volume per hectare.

关键词： Basal area increment Diameter growth Regression analysis caspian forests

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

Over-mature beech trees (Fagus orientalis Lipsky) and close-to-nature forestry in northern Iran

引用

Journal of Forestry Research 2012年第2期23卷 289-294页

作者： Mostafa Moradi Mohammad R.Marvie Mohadjer Kiomars Sefidi Mahmoud Zobiri Ali Omidi Faculty of Natural Resources University of TehranKarajIran Faculty of Agriculture University of Mohaghegh ArdabiliArdabilIran FRWO(forests Range and Watershed Management Organization of Iran)RashtIran

Oriental Beech is the most important commercial tree species in northern Iran. In recent years wood production companies interested in felling large beech trees for profit have challenged advocates of close-to-nature silviculture who favor conservation. Our study objective was to assess the economic value of over-mature beech trees by relating tree diameter （DBH） to amount of decay. Based on the location of onset of decay, we categorized three types of decay as stump, stem, and crown decay. Trees of greater diameter （age） typically showed greater decay in the stem. Percent of decayed volume, diameter of decayed tissue, and length of decay in tree stems varied between 0.5%-64.3%, 15 cm-75 cm, and 2.0-19.5 m, respectively. With increasing trunk diameter, the propor- tion of truck decay increased. Red heart and dark red heart constituted 25% and 14.3% of sampled trees, respectively. However, we found no correlation between intensity of stem decay and morphological charac- teristics of trees. Seedlings were not abundant around the bases of over-mature trees, suggesting that the trees did not contribute to regeneration of the stand. Beech trees of diameter 〉1 m do not provide valu- able round wood for industries and cause to raise wood production costs. We recommend that these trees 〉1 m DBH should be retained in forest stands because of their low commercial value but high ecological and conservational values such as maintaining biodiversity in forest ecosystems.

关键词： caspian forests close-to-nature forestry Fagus orientalis red heart and stem decay Iran

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

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

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

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：