Near-natural Management Research Articles

湖北省九华山林场不同树种配置杉阔混交林林分空间结构特征分析

PDF HTML阅读 XML下载 导出引用 引用提醒 湖北省九华山林场不同树种配置杉阔混交林林分空间结构特征分析 DOI: 10.5846/stxb201810122215 作者: 作者单位: 北京林业大学水土保持学院,北京林业大学水土保持学院,北京林业大学水土保持学院,北京林业大学水土保持学院 作者简介: 通讯作者: 中图分类号: 基金项目: 国家重点基础研究发展计划（2017YFC0505500，2017YFC0505504） Analysis of the stand spatial structure of Cunninghamia lanceolata-broadleaved mixed plantation on a Jiuhua Mountain farm, Hubei Province Author: Affiliation: College of Soil and Water Conservation,Beijing Forestry University,College of Soil and Water Conservation,Beijing Forestry University,College of Soil and Water Conservation,Beijing Forestry University,College of Soil and Water Conservation,Beijing Forestry University Fund Project: The National Basic Research Program of China (2017YFC0505500、2017YFC0505504) 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:以三种（杉木+少量栎类、杉木+栎类+光皮桦、杉木+栎类+光皮桦+马尾松）不同树种配置的杉阔混交林为研究对象，计算了角尺度、大小比数、混交度三个林分空间结构指标，全面分析了湖北省九华山林场不同树种配置杉阔混交防护林林分空间结构特征，结果表明：优势树种主要有杉木（Cunninghamia lanceolata（Lamb.）Hook.）、栎类（Quercus L.）及光皮桦（Betula luminifera）三种，并有少量马尾松（Pinus massoniana）散生于林内，生长优势也较弱。不同树种配置所呈现的林分空间结构也不相同。树种配置Ⅰ（杉木+少量栎类）的角尺度平均值为0.42，大小比数平均值为0.31，混交度平均值为0.18，林木空间分布格局和生长优势度均较好，但混交程度较弱，近乎杉木纯林，对应的生物多样性也会较小。树种配置Ⅱ（杉木+栎类+光皮桦）的角尺度平均值为0.5，大小比数平均值0.32，混交度平均数0.48，空间分布格局整体呈现随机分布；林木主要处于亚优势生长状态，混交度以中度-强度混交为主；而树种配置Ⅲ（杉木+栎类+光皮桦+马尾松）的角尺度平均值为0.58，大小比数平均值0.51，混交度平均数0.54，林木空间格局呈现聚集分布，生长优势水平中庸，为中度混交。全面分析林分空间结构，可以明确林分空间结构中存在的不合理情况，为合理择伐以及近自然经营提供科学依据，使该地区的杉阔混交林的多种功能得到可持续发挥。 Abstract:In order to analyze the spatial structure of Cunninghamia lanceolata-broadleaved mixed plantation on a Jiuhua Mountain farm, three different composition of Cunninghamia lanceolata-Broadleaved Mixed Plantation was taken as the study object, three spatial structure parameters, the angle index, mingling degree, and neighborhood comparison, were calculated. The results showed that the dominant species were C. lanceolata, Quercus L., and Betula luminifera; additionally, a small amount of Pinus massoniana was scattered throughout the forest. Different tree species compositions presented different spatial structures:composition I had an average angle index of 0.42, average neighborhood comparison value of 0.31, and average mingling degree value of 0.18; composition Ⅱ had an average angle index of 0.5, average neighborhood comparison value of 0.32, and average mingling degree value of 0.48; and composition Ⅲ had an average angle index of 0.58, average neighborhood comparison value of 0.51, and an average mingling degree value of 0.54. This comprehensive analysis of the spatial structure of the forest on Jiuhua Mountain farm reflects the unreasonable circumstances in the spatial structure of the forest, provides a scientific basis for guiding reasonable selective cutting and near-natural management, and enables the multiple functions of the Cunninghamia lanceolata-broadleaved mixed plantation in this region to be sustainable. 参考文献 相似文献 引证文献

Inventory of the degree of tree defoliation in small areas

The employment of small-area surveys for evaluating forest health is becoming increasingly important because in recent years, new ecological methods of management and conservation have been introduced in commercial forests and in the partial protection zones of national parks. In Poland, in relatively small areas, including forest sections, nature reserves or their fragments, close-to-nature management and near-natural management have been introduced and, in protected areas, typical partial protection is giving way to passive protection. Radical changes in the ways of management and conservation have developed a need for monitoring possible changes in the condition of trees, mainly through the application of precise, small-area methods for assessing their health. The aim of this paper is to present a small-area survey for assessing the degree of tree defoliation and its preliminary verification, in particular the evaluation of the degree of defoliation to fir ( Abies alba Mill.), beech ( Fagus sylvatica L.), pine ( Pinus sylvestris L.), larch ( Larix decidua Mill. subsp. polonica [Racib.] Domin) and oaks ( Quercus robur L. and Q. petraea [Matt.] Liebl.) on Chełmowa Góra Hill in the Świętokrzyski National Park (Poland). Part of the area of Chełmowa Góra comprises a strict nature reserve, set up in 1921, which is one of the oldest strict nature reserves in Poland. The area of Chełmowa Góra is slightly more than 183 ha. The degree of tree damage, determined on the basis of the degree of defoliation, was shown in sub-blocks P 3 of the system of information on natural environment (SINUS). To estimate the spatial distribution of the degree of tree defoliation, survey sampling – based on the scheme of simple random sampling with replacement (SRSWR) – was used. In 1999, Chełmowa Góra's beech and larch were in the best condition, and the worst were young-generation fir, pine and oak. During preliminary verification of the applied method, the mean total errors of the evaluation of proportions of trees in the distinguished defoliation classes, calculated as α = 0.05, reached almost 31% in particular sub-blocks P 3 of the SINUS system; however, in most cases they did not exceed 20%. The average values of mean total errors, calculated for particular tree species in all sub-blocks P 3, were generally lower than 20%. The applied method of inventory enables the assessment of the degree of defoliation and spatial differentiation of tree health in small areas, which in turn, allows the detailed planning of protection and silvicultural measures. The proper assessment of the extent of tree defoliation and its spatial distribution is of fundamental importance for employing the ecological methods of management and rational protection of forest ecosystems, and should be included in the monitoring of both economically used and protected forests.

Economic analysis of near-natural beech stand management in Northern Germany

Based on an empirical study of the forest practise at Lauenburgische Kreisforsten in Northern Germany an economic analysis of near-natural beech stand management is performed. The profitability, cash flow and economic flexibility of near-natural management (NNM) is compared to that of converting to: (i) Norway spruce, (ii) a clear felling beech regime with a rotation of 120 years (CF) and (iii) a cyclic beech regime with a regeneration thinning at stand age 90 and liquidation of the last holdovers at age 110 (CYC). The internal rate of return (IRR) of NNM is 2.9%, which for many investors would be a satisfactory real rate of return. For required real rates of return less than 2.5%, the net present value (NPV) of NNM exceeds the NPV of clearing the stand and planting Norway spruce at all stages of the rotation as well as the NPV of the two alternative beech regimes. When comparing the profitability of the alternatives using IRR as criteria, both of the alternatives CYC (IRR=3.3%) and Norway spruce (IRR=3.1%) should be preferred above NNM and CF (IRR=1.8%). However, it was discussed that when comparing investment alternatives like those presented in this paper the choice between investment alternatives should be dictated by their NPV at the required rate of return and not their IRR. In comparison to the management alternatives CYC and CF, NNM provides high mean annual net revenue, which exhibits relatively small fluctuations during the rotation. The latter may be important, especially at forest districts which do not have forest stands in the entire range of age classes and therefore may foresee periodical lack of liquidity. Due to the prolonged retention of the holdovers, the accumulation of capital in the forest is greater for NNM than for CYC and CF. Since economic flexibility of a silvicultural regime to a large extent is associated with the ability to accumulate liquid reserves in the forest, NNM may provide the owner with greater economic flexibility than the two shorter-rotation beech alternatives. It is concluded that near-natural beech stand management may provide an economically sound alternative to other, more traditional regimes for investors having a required real rate of return within the range common to most forest investments.