黑龙江省大兴安岭林区火烧迹地森林更新及其影响因子

林火干扰是大兴安岭森林更新的影响因子之一,研究火烧迹地森林更新的影响因子(立地条件、火前植被、火干扰特征)对理解生态系统的结构、功能和火后演替轨迹具有重要意义。选取呼中及新林林业局55个代表性火烧样地,利用增强回归树分析法分析了火烧迹地森林更新的影响因素。结果表明:(1)立地条件是影响针、阔叶树更新苗密度的主要因素;海拔对针叶树更新苗密度的影响最大;坡度对阔叶树更新苗密度影响最大;(2)距上次火烧时间对针叶树更新苗比重影响最大,其次是林型;(3)中度林火干扰后森林更新状况好于轻度和重度火烧迹地。根据火烧迹地森林更新调查分析可知:林型影响火后演替模式,火前为针叶树或阔叶树纯林,火后易发生自我更新(火后树种更新组成与火前林型相同),而针阔混交林在火干扰影响下易于发生序列演替(火后初期以早期演替树种更新为主)。     

金钟山亚热带森林林窗特征与木本植物多样性的关系

开展林窗空间格局与林下木本植物多样性关系的研究,对于认识森林物种共存、生物多样性维持以及生态系统可持续发展具有重要意义。本研究以广西金钟山自然保护区24 hm²永久森林动态监测样地为对象,采用机载激光雷达获取样地点云数据,通过R语言提取林窗并计算各林窗的形状复杂指数,利用相关分析量化林窗特征与林下木本植物多样性的关系。结果表明：该研究区林窗空隙率为6.16%,密度为15.5个·hm^-2,平均面积为39.72 m²,整体以微小和中型林窗为主;林窗空间分布格局存在地形分异特征,多分布于低海拔和缓坡区域;林窗形状复杂指数与香农指数、物种丰富度指数均呈正相关,且在低海拔和陡坡处表现更加明显。本研究揭示了亚热带森林林窗植被更新特征,对区域生物多样性保护具有一定指导作用。     

福建省果树寒(冻)害短期精细预报预警技术

根据福建省68个气象站1963-2008年冬季气候资料,利用数理统计和GIS方法,对福建省果树寒(冻)害短期精细预报预警技术进行了研究.结果表明:福建省果树寒(冻)害预警期为12月上旬-翌年2月中旬,预警关键期为12月中旬-翌年1月中旬;利用逐步回归建立的福州、厦门和邵武3个探空站日最低气温短期预报模型,经差值法移植后,可以用于全省各气象台站日最低气温短期预报;建立各气象台站日最低气温与经度、纬度、海拔高度的地理关系推算模型,利用GIS制作日最低气温预报分布图,可以开展日最低气温空间精细预报;结合荔枝、龙眼、香蕉等南亚热带果树寒(冻)害指标,对果树寒(冻)害的发生、发展和范围进行短期预报预警;2009年利用差值移植法开展各气象站最低气温(t_d)的短期预报:≤1℃的预报准确率为58.3%,≤1.5℃的预报准确率为83.3%,≤2℃的预报准确率为91.7%;短期预报模型具有一定的预报能力,能作为冬季低温定量预报方法.

Abstract：

Based on the 1963-2008 meteorological data from 68 weather stations in Fujian Province,and by using mathematic statistics and GIS technique,the short-term subtle forecast and early warming methods for cold (freezing) damage of fruit trees in the province were approached.The forecast period for cold (freezing) damage of fruit trees was from early December to next early February,and the key period for warning low temperature was from mid December to next mid January.The short-term forecast equations for the minimum daytime temperature in Fuzhou,Xiamen,and Shaowu were established by stepwise regression analysis,which could be used for the forecast of short-term minimum temperature by all of the meteorological observation stations in Fujian Province by means of differential algorithms.Based on the data of longitude,latitude,and altitude,the geographical relational prediction model of the minimum daytime temperature was established,and the distribution map of forecasted low temperature was drawn with GIS technology,which could subtly forecast the minimum daytime temperature of whole Fujian Province.In combining with the cold (freezing) damage indices of fruit trees such as litchi,longan,and banana in southern subtropical monsoon climate zone,the forecast information of warning cold (freezing) damage of fruit trees were popularized,and the occurrence,development,and range of cold (freezing) damage for fruit trees were forecasted in short-term.By means of differential algorithms,the short-term minimum temperature was forecasted by all weather stations in the Province in 2009,and the forecast accuracy of ≤1 ℃,≤1.5 ℃,and ≤2 ℃was 58.3%,83.3%,and 91.7%,respectively.It could be seen that our short-term forecast model possessed a certain forecast capability,and could be used for the quantificational forecasting of low temperature in winter.     

基于GIS的福建省双季稻气候-土壤生产潜力

基于GIS建立了福建省双季稻生产空间数据库和属性数据库,利用改进的农业生态区域法,计算了福建省各县市双季稻的光温、气候、气候-土壤生产潜力,通过分级统计和制图,分析了福建省双季稻生产潜力数值分布和空间分布特征及潜力开发优势区.结果表明:人为调节农田水分到最适状态时,可使全省双季晚稻气候生产潜力平均增加1 800 kg·hm-2;人为调节肥料到最优状态时,可使全省双季稻气候-土壤生产潜力平均增加4 000 kg·hm-2,潜力很大;各区双季稻气候-土壤生产潜力开发优势值南部大于北部,其中以闽西南为最大.根据各级生产潜力的变化特点,明确农业投入方向,提出福建省粮食安全的对策建议:严格限制非农业用地,稳定双季稻种植面积;采用适合的双季稻品种搭配,充分利用各地农业气候资源;建设旱涝保收田;增施有机肥、种植绿肥,提高土壤肥力;针对福建省双季稻潜力优势开发区,分批重点投入.