浙江西天目山古树树干健康状况及其随海拔梯度变化规律

古树作为组成和支撑森林和城市生态系统的重要组成部分,为各种动植物的生长提供了条件,为人类社会提供多种生态系统服务。分析古树树干腐烂及空洞状况沿海拔梯度的分布规律及其限制因素,有助于古树管理和保护策略的制定与实施。基于PICUS应力波树木断层图像诊断仪,本研究对浙江天目山国家自然保护区内不同海拔梯度上古树树干的腐烂及空洞情况进行了定量评估。共调研137株古树,结论如下：古树树干胸高断层处腐烂及空洞面积所占比例平均值为18.89%;古树树干腐烂及空洞面积占比在不同物种间存在一定差异;古树树干健康状况与海拔和气候因子之间存在一定的相关性,主要表现为随海拔升高,树干内出现腐烂及空洞的古树增多,且腐烂及空洞面积占比不断增大,这一相关性在不同树种之间也存在差异。     

园林树木虫害防治技术

作者从有益于充分发挥城市生态系统的整体功能出发,紧密结合本地实际给出了食叶,蛀干、地下三大类害虫的防治技术,并从六个方面综合阐述了园林害虫的生态防治与技术。     

研究历史气候变化的现代科学技术

除利用历史文献方法和现代分析技术研究历史气候外,树木年轮法、生物学方法、同住素法、旱灾异年频数法等,也是研究历史气候的重要方法。     

基于L系统的树木建模与仿真

基于L系统的建模方法是虚拟树木仿真的一种常用方法。针对传统L系统方法绘制的树木可交互性不强,造型呆板,绘制速度较慢的缺点,对L系统绘制流程进行改进以减少不必要的字符串重写次数和分形计算量;通过对重写规则引入概率因子来获得更好的随机性,进一步提高真实感;通过文中提出的SCA算法(Slices-Compression Algorithm)减少绘制树木分枝需要的矩形数量,提高绘制速度。实验结果表明,该方法绘制的树木具有较好的真实感,可交互性强,且绘制速度较快。     

Reconstructing mean maximum temperature of growing season from the maximum density of the Schrenk Spruce in Yili, Xinjiang, China

To study the historical temperature variation in Yili of Xinjiang, the tree-ring chronologies of maximum density （MXD） and tree-ring width （TRW） were established with the Schrenk Spruce （Picea schrenkiana Fisch. et Mey） collected from six sites to analyze the characteristics and ability of response to climate change. The results suggest that the MXD chronology of the Schrenk Spruce from different sampling sites responded to climate change well and were positively correlated with the mean maximum temperature and the mean temperature from April to August in the study area. The mean maximum temperature anomaly from April to August, spanning the years from 1848 to 2000, was reconstructed by three MXD chronologies which were selected by stepwise regression. The reconstructed function was stable and explained 56.2% of the variance. The reconstructed results indicated a cold span of 153 years in spring and summer from the beginning of the 1950s to the beginning of the 1970s in the Yili valley. No strongly increasing tendency was detected in the mean maximum temperature anomaly from April to August during this reconstructed period.     

沈阳东陵公园与陨石山森林公园SO2污染及树木含硫量的比较分析

通过实测分析,东陵公园的ＳＯ２含量超标１．５８倍,环境质量恶化,树木含硫量也明显增高;损石山公园则是基本没有污染的浏览地。主要乔木树种平均含硫量低有前者９１．５％,可作为植物污染生理生态研究的参照区;阔叶乔木的含硫量〉阔叶灌木〉针叶乔木,为城市环城林营造提供了乔灌混合的实验依据。     

浙江西天目山天然林及银杏种群考察报告

在完成国内多处同类型研究的基础上,笔者对西天目山双清溪沟谷天然林及其银杏进行了专题考察,所获第一手资料包括：双清溪森林古道样带式路线考察立木分布平面图;天目山双清溪天然林中银杏及伴生树种调查总表;双清溪天然林中银杏种群调查明细表;“5代同堂银杏”的树木形态学调查研究;禅源寺古森林群落的成分、结构及性质考察等。在充分分析的基础上作者认为,双清溪天然林原应属於典型“落叶与常绿阔叶混交林”群落,现已进入“针阔叶、落叶与常绿阔叶混交林”演替阶段。该演替系人为干扰下的一种“偏途演替”。银杏种群参与了演替和历史发展的全过程,因此,它们应该是野生的。“5代同堂银杏”建议正名为“无性系多代同株银杏”比较恰当。禅源寺古森林群落是双清溪沟谷天然林的延伸和残余部分,可简称为“禅源寺古森林残存群落”。     

通过树木年轮δ13C重建大气CO2浓度的可靠性探讨

为了探讨利用树木年轮碳同位素比及其模型重建历史大气ＣＯ２浓度的可靠性,对南亚热带条件下生长的几个主要树种的一些相关生理指标进行了测定。结果发现叶片光合速率Ａ和气孔导度ｇ的比值Ａ／ｇ和细胞间ＣＯ２浓度Ｃｉ随环境和树种特性有较大的变化,与前人对轩控制实验所取得的关于这两个值不变的结论不同,从而对以Ｃｉ恒定为前提通过树木年轮δ＾１３Ｃ重建大气ＣＯ２浓度的可靠性提出了怀疑。根据目前对Ｃｉ等值变化机理的认识     

Response of tree-ring width to rainfall gradient along the Tianshan Mountains of northwestern China

By comparing the long-term tree-ring growths at various geographic scales, we can make clear the effects of environmental variations on tree growth, and get an understanding of the responses of forest ecosystems to the possible changes in global and regional climate. Radial tree-ring growth of Picea schrenkiana and its relationship to air temperature and precipitation were investigated across longi- tude transects on the north slopes of the Tianshan Mountains in northwestern China. Tree-ring samples were collected and residual chronologies were developed for three different regions along a gradient of decreasing precipitation from west to east. Response-function analysis was conducted to quantify the relationships between tree-ring chronologies and climate variables, such as monthly mean temperature and monthly precipitation from 1961 to 1998, using the PRECON software program. The statistical characteristics of the chronologies showed that the three chronologies constructed in this study con- tained significant environmental signals and were well suitable to reveal the impacts of climatic change on tree growth and forest productivity. Annual ring-width variations were similar among the three sites, but the variability was greatest in the east. This research showed that the growth trends of Picea schrenkiana in the Tianshan Mountains have not followed a uniform pattern. Response-function analy- sis indicated that there were significant correlations between tree growth and climatic factors in all the three regions, among which precipitation was the principal. With decreasing precipitation, the response of tree-ring widths to increasing temperature changed from a positive to a negative correlation. As for precipitation, the positive relationship to tree-ring width always dominates. It could be expected that with increased temperature and decreased precipitation, the importance of precipitation to tree growth would increase, and the response of tree growth to environmental changes would also increase. This study emphasizes the importance of regional-scale investigations into the biosphere-climate interac- tions. The results of this research indicated a substantial increment of tree-ring radial growth as a re- sult of warmer and wetter climate in the eastern regions. However, climate change will have less effect on forest growth and primary production in the western regions.     

基于Java的树木年轮分析系统研究

树木年轮的轮数和宽度是进行树轮气候学、树木生长规律及森林生产力测算研究的重要基础,是研究树轮相关科学中的重要数据,在测量树轮数据时偏差的大小将直接影响各项研究的准确性和精度.针对树轮检测定年过程中遭遇的各种问题,为了树木年轮判读过程中的准确性和年轮测定速度的提高,从而基于Java语言设计实现了简单的树木年轮分析系统.旨在借助计算机程序对树木年轮样品的树芯图像进行自动判读,来确定树木年轮轮数、轮宽等数据,以此达成通过简单操作便可以高效、快捷的获取树木年轮数据的目的.最终实现对树木年轮检测的自动化,为研究树轮学等需要树木年轮数据的学科提供支持,提高效率.