Effect of forest structure and health on the relative surface temperature captured by airborne thermal imagery – Case study in Norway Spruce-dominated stands in Southern Finland

The effect of forest structure and health on the relative surface temperature captured by airborne thermal imagery was investigated in Norway Spruce-dominated stands in Southern Finland. Airborne thermal imagery, airborne scanning light detection and ranging (LiDAR) data and 92 field-measured sample plots were acquired at the area of interest. The surface temperature correlated most negatively with the logarithm of stem volume, Lorey’s height and the logarithm of basal area at a resolution of 254?m² (9?m radius). LiDAR-derived metrics: the standard deviations of the canopy heights, canopy height (upper percentiles and maximum height) and canopy cover percentage were most strongly negatively correlated with the surface temperature. Although forest structure has an effect on the detected surface temperature, higher temperatures were detected in severely defoliated canopies and the difference was statistically significant. We also found that the surface temperature differences between the segmented canopy and the entire plot were greater in the defoliated plots, indicating that thermal images may also provide some additional information for classifying forests health status. Based on our results, the effects of forest structure on the surface temperature captured by airborne thermal imagery should be taken into account when developing forest health mapping applications using thermal imagery.     

油桐嫁接繁殖技术的研究

本试验研究对油桐嫁接繁殖中嫁接材料的选择、嫁接方法的应用、嫁接时期的确定,影响嫁接成活率的因素以及嫁接后的科学管理等进行了研究。     

德国森林功能理论的演变与启示

森林功能理论最早应用于19世纪初的德国森林科学中,其理论演变在德国的林业发展中具有重要地位。文中从森林功能的初认识阶段、再认识阶段、多功能理论阶段及多功能林业的应用阶段对德国森林功能理论演变进行了研究,并从创新林业经营管理理念、加大公共财政扶持力度、促进科技支撑林业发展、创新林业管理机制体制和开展全民森林教育等方面探讨了其对林业的5点主要启示,对于我国多功能林业建设具有一定的参考作用。     

Clearcutting forestry and Eurasian boreal forest grouse: Long-term monitoring of sympatric capercaillie Tetrao urogallus and black grouse T. tetrix reveals unexpected effects on their population performances

Along the succession gradient of the boreal forest ecosystem, black grouse Tetrao tetrix inhabits the early and capercaillie Tetrao urogallus the latest stages. When converting old forest to clearcuts and plantations, commercial forestry has therefore been assumed to affect capercaillie negatively and to be favourable to black grouse. During a 30-year period (1979-2008) we monitored sympatric populations of the two species in a forest in southeast Norway based on annual spring and autumn censuses and radio-marked birds. During this period, the proportion of old, semi-natural forest was halved and clearcuts and young plantations increased accordingly. The grouse populations did not change as predicted. While the trend in August numbers of adult black grouse declined, males more than females, abundance of adult capercaillie remained unchanged. Number of males at leks showed similar patterns. Equally surprising, breeding success (number of chicks per female in August) of both species increased, thus indicating that the populations were regulated more by variation in adult survivorship than by recruitment of young birds. No correlations were found with changing climatic factors (precipitation and temperatures in winter and spring, snow depth and time of snow melt), except that year-to-year breeding success was positively correlated with minimum temperatures during 2 weeks posthatch. The results are explained by a combination of more flexible habitat selection than previously assumed and a changing predator regime: In the early period, nearly all capercaillie leks were located in old, semi-natural forest, but as plantations grew older (>30 years), new leks were established there. Similarly, while young capercaillie broods used old semi-natural forest almost exclusively when the study started, they frequently used middle-aged plantations, especially those with a ground cover of bilberry Vaccinium myrtillus, when these became common in later years. The increasing breeding success could largely be explained by more females rearing chicks successfully, presumably due to a marked decline in the main nest predator, the red fox Vulpes vulpes. A practice of thinning of the old, semi-natural forest some years prior to final harvesting probably facilitated predation of black grouse by goshawks Accipiter gentilis. Contrary to many beliefs, our results indicate that both capercaillie and black grouse are quite tolerant to changes in forest management regimes. In our study, numerical and functional responses of predators (mainly red fox and goshawk) apparently played a more important role in regulating grouse numbers than habitat factors per se.     

森林生态系统适应性经营研究

介绍适应性管理的概念及其理论与应用现状,在此基础上,提出了森林生态系统适应性经营的概念,并结合适应性管理的框架,提出了森林适应性经营的思路.阐述了适应性管理在理论与实践中存在的问题和难点,认为森林生态系统适应性经营是一个长期的不断循环的过程,根据森林生态系统的自适应性和多功能性,通过监测与评估,不断收集新信息,及时调整经营措施等是森林适应性经营的重要内容.     

双柏县国有林场发展现状与改革对策思考

双柏县森林资源丰富,发展林业具有得天独厚的优势,8个国有林场是林业建设的主力军,但随着时代变迁和社会进步,国有林场当前的管理体制和经营机制与现代林业发展已不相适应,"大资源、小产业"现象突出。文章阐述双柏县国有林场发展历程和现状,分析了面临的发展障碍,提出了转变体制,强化职能;完善机制,释放活力;调整结构,提高效益;拓宽融资渠道,加大投入;强化科技,集约经营等深化改革对策措施。     

我国草坪业现状分析

本文分析了我国草坪业的现状，从三个方面指出了我国草坪业所面临的亟待解决的问题。     

我国森林经营方案问题研究评述

回顾了森林经营方案编制的历史,较全面地阐述了森林经营方案在编制、实施与管理中存在的问题.指出了编制与实施森林经营方案在理论上与技术工作中需要进一步研究解决的问题.对森林经营方案编制的发展趋势进行了初步分析.     

基于不同立地因子的杉木与马尾松地位指数相关模型

偏差较大、精度不够高是地位指数相关模型应用的关键问题.通过科学地划分雪峰山地区的立地因子,有效地选择立地因子,采用SPSS对雪峰山地区324块同时具有杉木和马尾松地位指数值数据的样地进行11种方程的模拟分析,建立了基于立地因子的雪峰山杉木与马尾松地位指数相关模型,模拟效果较好;预测误差绝对差值分布在0~0.7 m之间,95%以上分布在0.3 m左右.解决了地位指数代换偏差较大、精度不够高的问题,提高了模型的实用性能.