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辽河源自然保护区森林群落生长潜能及影响因子研究

Study on Forest Community Growth Potential and Impact Factor in Liaohe River Nature Reserve

【作者】 张进献

【导师】 孙保平;

【作者基本信息】 北京林业大学 , 水土保持与荒漠化防治, 2010, 博士

【摘要】 以辽河源自然保护区8种典型森林群落类型为研究对象,通过对不同森林群落的森林生长、生物多样性、气象因子和土壤理化特征分析研究的基础上,对其之间的影响因子进行相关关系分析,确定影响森林生长的主要因子,为研究区森林资源的管理和保护提供科学的理论依据。研究结果包括以下几方面:(1)森林群落物种多样性研究:①α物种多样性研究结果表明,灌木物种丰富度在各个群落中均小于草本层,尤其是油松、栎树针阔混交林群落的差异更为显著。总的来看,油松纯林,落叶松、白桦针阔混交林物种丰富度较小;草本层均匀度指数最大的群落是油松、栎树针阔混交林,灌木层均匀度指数最大的是杂木林,最小的为油松、栎树针阔混交林和栎树纯林。物种多样性两种指数变化趋势相似,杨树、桦树、栎树阔叶混交林灌木的物种多样性指数最大,栎树纯林最小;栎树纯林的草本物种多样性指数最大,杂木林草本两种指数最小。②物种β分析结果:灌木层华北落叶松林和油松、蒙古栎针阔混交林(AF)=白桦纯林群落和油松、蒙古栎针阔混交林(CF)=蒙古栎纯林群落和油松、蒙古栎针阔混交林(DF)=油松、蒙古栎针阔混交林和杂木林群落(FH),这几个群落之间相异性系数最大,而蒙古栎纯林群落和杂木林群落(DH)相异性系数最小,共有种最多,异质程度最低;草本层相异性系数最大的是落叶松白桦混交林群落和杂木林群落(EH),相异性最小的是华北落叶松林和落叶松白桦混交林群落(AE)(2)土壤理化特征:①研究地几个典型森林群落的土壤容重均表现出随土层深度增加而上升的趋势,不同林分间各土层土壤容重平均值在0.99-1.19g/cm3之间,落叶松纯林群落土壤容重表现为最小,杂木林最大;不同森林群落的不同孔隙指标随土层深度的增加而呈减少的趋势。杨树、桦树、栎树阔叶混交林总孔隙度最大,杂木林群落最小;油松纯林的毛管孔隙度最大,落叶松、白桦针阔混交林最小;非毛管孔隙度最大的为落叶松、白桦针阔混交林,最小的为油松纯林;油松、栎树针阔混交林田间持水量表现为最大,杂木林最小;落叶松纯林的毛管持水量最大,杂木林最小,杨树、桦树、栎树阔叶混交林最大,杂木林最小。②土壤化学特征:研究地区森林群落的平均土壤全N含量为0.2%,N素较丰富,全N含量最大的为华北落叶松群落。不同林分土壤碱解N含量均随土层增加呈下降的趋势。土壤碱解N含量最大的为华北落叶松群落;华北落叶松群落全P含量在不同的土层中均表现为最大,全P含量最小的均为杨树、桦树、栎树阔叶混交林,研究地土壤速效磷平均含量为19.8mg/kg,对于大多数树种来说已能满足需要;研究地土壤全K平均含量为2.83%,属于含K量较丰富的地区。群落土壤速效钾的比较来看,均随土层深度的增加而呈现减少的趋势。不同林分之间差异较大,其中,栎树纯林群落平均速效钾含量最大,最小为油松林群落129.63mg/kg,从土壤速效钾含量等级划分标准来看,研究地区速效钾含量较丰富。(3)林分结构与生长分析:①针叶林林分结构与生长分析表明,落叶松林分平均直径值为21.32cm,林分直径分布的偏度系数为0.449,峰度系数为0.059,林分直径分布结构为截尾正态分布。油松林分平均直径值为20.82cm,林分直径分布的偏度系数为0.227,峰度系数为0.215,林分直径分布结构基本服从正态分布;林分各径阶的树高随着直径的增大而呈现增大的变化趋势,树高曲线的拟合优度都大于0.8,拟合效果较好,在同样林分径阶情况下,落叶松林的林分平均高要比油松林的林分平均高大;对针叶林代表性树种落叶松林分和油松林分进行胸径、树高、材积生长方程的拟合,结果显示,拟合优度均在0.99以上,拟合优度较高。②阔叶林林分结构与生长分析,白桦林分平均直径值为14.44cm,林分直径分布的偏度系数为0.810,峰度系数为-0.032,林分直径分布结构为右偏尾正态分布。杨树林分的平均直径值为14.42cm,林分直径分布的偏度系数为-0.239,峰度系数为-0.452,林分直径分布结构基本服从正态分布;阔叶林分的各径阶林分平均高拟合曲线的复相关系数都达到了0.8以上,拟合效果较好。在同样林分径阶情况下,杨树林的林分高要比白桦林的高;对阔叶林代表性树种白桦林分和山杨林分进行胸径、树高、材积生长方程的拟合,结果显示,拟合优度均在0.99以上,拟合优度较高。(4)根据辽河源地区8种不同森林类型群落,选取了7种土壤物理特征、7种化学特征和5种植物多样性指标进行相关分析,并建立了数学模型。结果表明,只有土壤田间持水量和物种丰富度指数达到极显著水平,和物种多样性的生物多样性指数H值也达到极显著水平,与生物多样性指数D值达到显著水平,而其他的均没有表现出显著性。(5)森林生长与气象因子的影响研究表明,①对研究地区主要树种胸径连年生长量与气候因子拟合结果表明,气象因子年平均气温、年平均最高气温和年平均风速3个因子被选入方程,说明这三个因子对当地树木直径生长影响最大。其中,林木生长与年平均气温表现出正相关,而和年平均最高气温呈现负相关。②对研究地区主要树种树高连年生长量与气候因子拟合结果表明,年平均最低气温、年降水量、年平均风速、年最大风速、年平均地表温度、年平均20cm地温6个气象因子被选入方程,说明这6个因子对于研究地区树木树高生长量关系密切。其中,年降水量、年平均地表温度、年平均风速与树高生长量呈正相关,而年平均最低气温、年最大风速、年平均20cm地温与树高生长量呈负相关。③由逐步回归分析结果可知,与材积连年生长量关系密切的气象因子是≥10℃积温、年平均风速、年最大风速、年平均地表温度和年日照时数5个气象因子被选入方程,其中,年平均地表温度与材积生长量呈正相关,而≥10℃积温、年最大风速、年最大风速、年日照时数与材积生长量呈负相关。(6)研究地区森林生产力及其影响因子分析结果显示:森林生产力随着各林分因子(海拔、坡度、林分密度)的增加呈现先增长后减少趋势,根据森林生产力和林分因子的偏相关系数可得:海拔对森林生产力的影响最大,其次为坡度,林分密度最小;与土壤物理特征(土壤容重、土壤总孔隙度、土壤饱和含水量)呈现“U”形,而与土壤养分特征(碱解N、速效P、全K、速效K)呈现倒“U”形的关系,按照其之间偏相关系数排序为:全K>速效K>速效P>碱解N>容重>总孔隙度>饱和含水量;研究地区森林生产力均随着植物多样性的增加而呈现减少的趋势。

【Abstract】 In the nature reserve of liaohe river,eight kinds of typical forest community types as the research object,the paper based on the analysis and research of the different forest community’s forests, biodiversity and soil physical and chemical characteristics,carried out related analysis between the influence factors and determined the main factors affecting forest growth,for the research areas of forest resources management and protection provide the theory basis.The research results included the following aspects:(1) The study on forest community species diversity:①The study of a species diversity show that shrubs species richness in various communities were less than the herb layer, especially mixed wood of pine-oak communities is more significant differences. In general, the species richness of Chinese pine pure forest and mixed wood of larch-birch is smaller; herb layer evenness index is the largest community in mixed wood of pine-oak; in the shrub layer evenness index,the biggest is in the spinney,the smallest is in mixed wood of pine-oak and pure forest of oak trees.The trend of two indices about species diversity is similar, the biggest species diversity index in the shrub is broadleaved mixed forest of poplar-birch-oak,the smallest is pure forest of oak trees; the biggest species diversity index in the herb is pure forest of oak trees.②the analysis results of speciesβ:these communities have the biggest community dissimilarity in the shrub layer,they are larch forest and mixed wood of pine-mongolia oak(AF),pure forest community of white birch and mixed wood of pine-mongolia oak(CF),pure forest of mongolia oak and mixed wood of pine-mongolia oak(DF) and mixed wood of pine-mongolia oak and spinney community(FH), the smallest community dissimilarity is the community of pure forest of mongolia oak and spinney which have the most common species and the lowest heterogeneity degree;in the herb layer,the biggest community dissimilarity is mixed wood community of larch-white birch and spinney(EH),the smallest is mixed wood community of larch forest-larch-white birch(AE).(2) The soil physical and chemical characteristics:①Several typical forest community study of soil bulk density are showing rising trend with soil depth increased.Average soil bulk density of various layers in different forest is 0.99~1.19 g/cm3.The smallest soil bulk density is the pure forest of larch,the biggest is spinney.The different pore indexes in different forest communities are showing decreaseing trend with soil depth increased.lt is the largest total porosity in broadleaved mixed forest of poplar-birch-oak,the smallest is in the community of spinney.Chinese pine pure forest has the maximum of capillary porosity,mixed wood of larch-white birch is the minimum.The largest non-capillary porosity is mixed wood of larch-white birch,the smallest is chinese pine pure forest.The largest field moisture capacity is mixed wood of pine-oak,the smallest is spinney.The largest capillary water holding capacity is pure forest of larch,the smallest is spinney.②Soil chemical characteristics:The average soil total N content is 0.2% in the study area of forest communities, N is more abundance; the largest total N content is larix principis-rupprechtii community.Different forest soils alkali solutions of N content of soil have downward trend with the increasing soil.The largest is larix principis-rupprechtii community.The largest total P content in the different layers is larix principis-rupprechtii community,the smallest is broadleaved mixed forest of poplar-birch-oak.The average content of soil available phosphorus is 19.8mg/kg, for most species it can satisfy the need.The average K content is 2.83% which belong to higher contain area. From the comparison of soil available K,the community presents a downward trend with soil depth increased.The different stands have large differences,among them, the largest is pure forest community of oak trees on average available K content;the smallest is 129.63mg/kg in pine forest community.From the soil content of available K and grading standards,the reaserch area has richer content of available K.(3) Forest structure and growth analysis:①Coniferous forest structure and growth analysis shows that:larch stand average diameter is 21.32cm,the skewness coefficient about stand diameter distribution is 0.449,kurtosis coefficient is 0.059,stand diameter distribution structure presents truncated normal distribution.Pine stand average diameter is 20.82cm,the skewness coefficient about stand diameter distribution is 0.227, kurtosis coefficient is 0.215,stand diameter distribution structure basically obeys normal distribution.The tree height of each diameter class present increasing trend with increasing diameter.Fitting goodness of tree height curve is more than 0.8 and fitting effect is better.In the same diameter class,larch forest is higher than pine forest in average height.Fitting growth equation of representative species of needle forest in larch and pine forests at breast height,tree height and volume growth, the result show that fitting goodness is high and above 0.99.②Broadleaved forest structure and growth analysis:In white birch forest,the average diameter is 14.44cm, the skewness coefficient about stand diameter distribution is 0.810,kurtosis coefficient is-0.032,stand diameter distribution structure presents skewed to the right end of the normal distribution.In poplar forest,the average diameter is 14.42cm,the skewness coefficient about stand diameter distribution is-0.239,kurtosis coefficient is-0.452,stand diameter distribution structure basically obeys normal distribution.Multiple correlation about each diameter’s average height of fitting curve is above 0.8 in broadleaved forest and fitting effect is better.In the same diameter class,poplar forest is higher than white forest in forest height; Fitting growth equation of representative species of broadleaved forest in white forest and poplar forests at breast height,tree height and volume growth, the result show that fitting goodness is high and above 0.99.(4) According to the Liao River source region 8 communities in different forest types, selecting the 7 types of soil physical characteristics,7 species of chemical characteristics and 5 kinds of plant diversity indicators were analysed and established mathematical model. The results show that, only a soil field capacity and species richness reaches extremely significant level index and species diversity in the biodiversity index H also reaches extremely significant levels, biodiversity index D reached a significant level,while others have not demonstrated notability.(5) Forest growth and the impact of meteorological factors studies have shown that:①in the study area, the fitting with DBH and annual increment results show that climatic factors, the annual average temperature of meteorological factors, annual average maximum temperature and annual average wind speed was elected to equation and explained that these three factors had the greatest impact on the local tree diameter growth. Among them, forest growth and annual average temperature showed positive, but with the average maximum temperature is rendered negative correlation.②On the research area in the main tree species tree, height growth of annual increment and climatic factors fitting results show average annual minimum temperature, annual precipitation, annual average wind speed, annual maximum wind speed, annual mean surface temperature and 20cm annual average ground temperature,6 factors were elected to the equation and illustrated the six factors with height increment having close relation. Among them, the annual precipitation, average annual mean surface temperature, wind speed and height increment was positively correlated.While the average minimum temperature, maximum annual average wind speed, temperature and tree 20cm high growth was negatively correlated.③By stepwise regression analysis we can see, meteorological factors closing volume growth of annual increment is≥10℃temperature, annual average wind speed, the annual maximum wind speed, the average surface temperature and year sunshine hours,5 factors were elected to the equation.Among them, the average surface temperature and volume growth of annual increment was positively correlated, while 10℃temperature, annual maximum wind speed, year sunshine duration and volume growth was negatively correlated.(6) The analysis result for forest productivity and its affecting factors showed:forest productivity appeared increased and then decreased trend with the increase of the stand factors (altitude, slope, stand density); there showed "U"-shaped quadratic polynomial about forest productivity and soil physical characteristics (soil bulk density, soil total porosity, soil saturated water content) (correlation coefficient above 0.7);there showed inverted U-shaped relationship about forest productivity and soil nutrient characteristics (available nitrogen、available P, total K, available K) (correlation coefficient is lower); forest productivity appear decreased trend with the increase of the plant diversity.

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