低影响开发理念下我国场地景观优化设计研究进展

低影响开发是以可持续水循环为核心的现代雨洪管理理念,越来越多地应用于场地景观优化设计中。基于我国低影响开发理念研究动态和场地景观优化实践,从景观雨水设施、场地雨洪调控能力影响因素、雨水设施量化、相关设计规范标准及规划设计方法等进行了总结,为优化场地景观设计提供参考。     

GIS技术在农业规划畜牧场选址中的应用

畜牧场选址是一项受多方面因素制约的工作。在利用GIS技术以前,畜牧场选址工作是需要多部门共同协作,进行实地调查,得到可以建设畜牧场的地块。不仅费力费时,而且无法准确评估防疫等各个方面的影响因素。笔者在概述地理信息系统在农业各领域应用的基础上,以吉林省永吉县中国-新加坡食品控制区为例,重点体现了GIS技术在畜牧场选址中的应用。利用GIS技术将规划区域的各种地物信息、交通信息、地形信息等有机结合,将图片资料以图形化方式转换为空间数据,并与其他非空间数据、资料等有机结合。结果表明：通过GIS技术可以使畜牧业规划在区域布局上更为合理;产业选择上更为科学、提高重点项目的可操作性,提升规划的可行性。在畜牧产业中,提高畜牧场选址的工作效率和准确度,同时更准确的了解规划区域的畜牧生产潜力,确定养殖规模和不同畜种发展方向。     

不同立地黑杨派无性系生长和多性状综合评选

以北京大兴区榆垡和青云店2个试验地营建的7个黑杨派无性系6年生试验林为材料,无性系间生长性状（胸径、树高和单株材积）存在极显著差异,且生长性状在无性系×试验地交互效应上亦存在显著差异。利用保存率、生长性状、蓄积量、单位面积碳储量、溃疡病和破腹病及蛀干害虫抗性等性状,以生态林和用材林为选育目标,采用性状权重的综合评分法,分别对2个试验地7个无性系开展多性状综合评价研究。结果表明,在2个试验地上,无论是以生态林还是用材林为选育目标,108杨（Populus ×euramericana cv.‘Guariento’）、107杨（P.×euramericana cv.‘Neva’）、中林2025（P.deltoides cv.‘Zhonglin2025’）和中林46（P.×euramericana cv.‘Zhonglin46’）等4个无性系生长量,各性状表现优良,可在该地区杨树人工林生产中推广。     

塞罕坝华北落叶松人工林立地质量评价

以华北落叶松人工林为研究对象,基于塞罕坝机械林场2012年森林资源二类调查数据,选取立地因子(坡向和土层厚度)和林分因子(树高和林龄),应用统计学方法划分立地类型,利用理查德(Richard)函数拟合立地指数,构建华北落叶松树高曲线,编制地位指数表,并对该区不同林龄(幼龄林、中龄林和近熟林)华北落叶松的6种立地类型进行立地质量评价,结果表明:阳坡中层土和阴坡厚层土立地质量为Ⅰ级,平均立地指数分别为12.15m、11.55m;阳坡厚层土和阴坡中层土立地质量为Ⅱ级,平均立地指数分别为11.39m、11.16m;阴坡薄层土和阳坡薄层土立地质量分别为Ⅲ级和Ⅳ级,平均立地指数分别为10.85m、9.87m。     

Long-term trends in height growth of Picea obovata and Pinus sylvestris during the past 100 years in Komi Republic (north-western Russia)

Abstract

Adapting forest management practices to the changing environment of Komi Republic requires an understanding of the response of unmanaged natural forests to climatic changes. Komi Republic is a region of north-western Russia where large areas of natural boreal forest still exist. Apical growth of Scots pine (Pinus sylvestris L.) (108 trees, 529 discs) and Siberian spruce (Picea obovata Ledeb.) (88 trees, 423 discs) was analysed using stem analysis techniques. Mean apical growth curves were calculated for four zones of boreal forests in two subsequent 50 year periods starting from 1900. A statistically significant increase in height increment of 40% for Siberian spruce and 30% for Scots pine was identified from samples representing the Komi Republic. Within this region statistically significant height increment increases were found in the middle taiga zone for Siberian spruce of 240% and Scots pine of 140%, while northern taiga Siberian spruce increased by 164%. Taking into account that trees were samples in remote untouched pristine forests, the main causes of increased height increment are suggested to be climatic, which shows a large increase in temperature (0.43°C during the past 30 years) and a modest decrease in precipitation (2.2% over the past 30 years).     

加拿大哥伦比亚省美国黄松广义代数差分型地位指数模型

基于3种常用的理论生长模型,利用代数差分法和广义代数差分法推导8个差分型地位指数模型。模型拟合采用加拿大哥伦比亚省美国黄松林分79个临时样地的纵向剖面解析木数据和分类变量回归的参数估计方法,模型筛选采用统计指标和图形分析相结合的方法,并着重突出了图形分析的重要性;同时,本文对于最佳模型的应用也进行了较为全面的分析研究。结果表明:1)广义差分型地位指数模型具有更高的预测性能;2)基于Hossfeld IV生长模型的广义差分型地位指数模型表现出了最佳的性能,推荐采用该模型对加拿大哥伦比亚省30～200年的美国黄松林分进行树高生长预测和立地质量分类;3)依据预测的相对误差,确定100年为最佳指数年龄。     

Soil-CO2 flux after patch scarification,harrowing and stump harvest in a hemi-boreal forest

Abstract

Stump harvesting is one way of increasing the amount of bioenergy, but little is known about the consequences of tree-stump harvesting on the carbon balance in the forest. Therefore, soil-surface CO₂ flux (soil respiration, R _s) was determined two years after clear-cutting for common soil disturbances occurring after patch scarification, harrowing and stump harvest in southern Sweden. R _s from intact soil was found to be of the same magnitude as emissions from areas of mixed humus, indicating only small effects of disturbance. Elevated mounds produced lower emissions than in the intact soil during the second year despite larger amounts of organic matter, probably due to low soil moisture. The lowest R _s was found in soil surfaces with exposed mineral soil. The treatment effects on R _s were estimated considering the actual area of different disturbances. During the first year, there was no difference in R _s among the treatments, whereas in the second year the flux was 10% higher after harrowing and stump harvesting than after patch scarification, implying that the effects on CO₂ flux after stump harvest were comparable to conventional harrowing. However, it is unclear whether this finding basically applies to regions where decomposition is limited by soil moisture during the summer.     

杉木第2代种子园不同地形土壤及植株养分比较

以杉木第2代种子园为研究对象,分析不同地形对种子园土壤及植株养分含量的影响.结果表明,随着坡位上升,杉木第2代种子园土壤及植株养分含量均呈逐渐下降趋势;同一坡位、同一土层深度,不同坡向杉木第2代种子园土壤及植株有效养分含量差异较大,总体而言,西坡有利于土壤有机质、有效磷及植株全氮、全镁及全铜的积累,东坡则有利于土壤速效钾及植株全钾、全钙及全锌的积累.     

北京山区主要造林树种刺槐的适地性研究

以北京山区主要造林树种刺槐为研究对象,采用数量化理论Ⅰ的方法,通过研究不同立地因子对人工刺槐林高生长与径生长的影响来分析刺槐的适地性。结果表明:土壤厚度、坡度是制约人工刺槐林高生长的最重要因子,坡位、土壤类型是影响人工刺槐林高生长的重要因子;土壤厚度是制约人工刺槐林径生长的最重要因子,坡度是影响人工刺槐林径生长的重要因子。研究结果确定了影响北京山区刺槐人工林生长的主导因子,可以为刺槐造林地的选择和科学经营提供依据。