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海岸带木麻黄群落与优势种群数量特征研究

Studies on the Quantitative Characteristics of Dominent Population in Casuarina Coastal Communities

【作者】 张璐璐

【导师】 吴承祯;

【作者基本信息】 福建农林大学 , 生态学, 2010, 硕士

【摘要】 木麻黄林是我国东南沿海最优良的固沙防护林树种,且是四旁绿化的好树种。目前关于木麻黄的研究多集中在生物量、生产力、各组分干重热值、去灰分热值及群落能量分布与结构特征等方面,其群落结构与种群生态学研究较少研究。通过野外调查,分析了长乐市大鹤国有林场木麻黄的生态位、分布格局、种群结构与动态等特征,目的在于了解木麻黄林的自然变化规律,从而为木麻黄防护林的合理经营提供科学依据。以400m2为取样水平,运用方差比率法、共同出现百分率、联结系数、点相关系数和卡方检验测定了主要树木种群间联结性。结果表明:以调查资料为基础来分析木麻黄种群结构特征以及动态变化,利用“空间代时间”,“横向导纵向”的方法编制木麻黄种群的特定时间生命表,绘制了种群的存活曲线,死亡率曲线,并用4个函数分析种群数量动态变化,最后进行谱分析。结果表明:木麻黄的存活曲线应属于Deevey-Ⅲ型,木麻黄种群早期死亡率极高,曲线斜率较大,环境筛的选择强度极大,只但是此后随着年龄增长,环境筛的选择强度减弱,木麻黄的死亡率较低,幼树阶段向营养阶段过渡相对平衡,存活曲线趋于平缓,木麻黄种群死亡率出现两个高峰,分别出现在第Ⅰ~Ⅱ龄级,第Ⅷ~Ⅸ龄级阶段。种群生存分析表明,木麻黄种群生存率函数单调下降,累积死亡率函数呈单调上升,说明木麻黄种群幼年死亡率极高,长成之后,种群趋于平衡稳定。马尾松种群的存活曲线应属于Deevey-Ⅱ型,表明马尾松种群各年龄死亡率基本相同,第Ⅵ-Ⅶ龄级马尾松种群死亡率为最高峰值。谱分析结果表明:木麻黄种群、马尾松种群的时间系列长度能足够表现出基本周期,且林分已达到成熟阶段,并能表现出明显的固有波动周期长度。根据样地实际情况和研究需要,将立地乔木按高度分为10级(0,+∞]来研究种群高度结构和级间失稳率。结果表明:木麻黄种群各个高度级进行数量统计,在所有样地中以第1高度级数量为最多,达到了9578株,占调查总株树的40.70%,以后每高度级呈现递减的趋势,马尾松种群高度结构中第6高度级所占比例为最大,达到38.96%。木麻黄第Ⅱ-Ⅲ高度级失稳率最高,达到69.7450%,马尾松幼龄林至中龄林阶段种群的级间失稳率基本上为负值,这表明马尾松幼龄林的数量相比较其它年龄段的个体数要少很多。根据实际调查数据,采用C、I、I&、PAI、Ca 5种聚集度指标以及Iwao方程对海岸带木麻黄种群的空间分布格局进行了系统研究,并比较其在取样尺度下的变化情况。结果表明:木麻黄的空间分布均呈聚集分布,且木麻黄在1600m2取样单元时,聚集度最强,这可能是由于影响种群分布各种因素在某种尺度上容易形成耦合关系,若有利于种群生长,种群个体容易在这种尺度上聚集成长。同时,本文还根据Iwao的M与X的回归方程,计算木麻黄在不同密度和允许误差下的理论抽样面积。本研究调查获得木麻黄的种群密度为3-8株/50m2,按理论抽样面积计算至少应取138个样方,而本研究在实际取样过程中取样样方数达256个,因此,本研究所取样的数量远远大于理论所需的抽样面积,说明本研究所测定木麻黄为聚集分布是可以相信的,取样的数量能够达到精度的需求。根据实际调查资料,以树种的重要值作为资源位上的表现特征,定量分析了木麻黄群落中主要树木种群生态位宽度,生态位相似性比例和生态位重叠。结果表明:木麻黄的生态位宽度最大,在群落中处于绝对的优势地位,这主要是由于其广泛的适应性,而马尾松和大叶相思的生态位宽度较小;群落中三个主要种群之间的相似性比例值不太高,生态位虽有一定程度的重叠,但总体仍然较低,群落内种间竞争并不十分激烈。其结果可作为进一步研究海岸带木麻黄群落结构、动态及种间关系的基础。以每木检尺所获得的胸径、树高等数值来计算重要值,并且据此来计算木麻黄与马尾松、大叶相思之间的种间关系,结果表明:木麻黄与马尾松表现出强的负联结性,木麻黄与大叶相思、马尾松与大叶相思之间,存在较弱的正联结,总体上来说,3个种间的联结趋势较弱,说明该群落不稳定,尚处于演替阶段。应用的描述种群增长改进模型,其具体解析式中共4个参数,K、C、a、θ,在参数的求解时,先给定初值,θ=1,这样转化为种群增长的S以空间单位为径级的时序关系所对应的木麻黄种群的基面积数值,采用改进单纯形法建立木麻黄种群基面积增长的Logistic模型,并对该模型进行参数优化,最后得到了木麻黄种群的内禀增长率为0.5884。通过对实测数据,对木麻黄种群进行密度效应和自然稀疏规律的研究,本文选择平均直径、平均木断面积(g)和林分总断面积(G)作为个体大小的指标,来表示林木株树与林木大小的关系。结果表明:木麻黄种群密度与林木大小的关系表明木麻黄种群密度对林分平均胸径、平均木断面积、林分总断面积均存在显著作用。在所拟合的各种模型中,以模型(41)为最优,回归效果及显著。因此,在经营木麻黄林时,必须切实重视林分密度控制管理,同时,这也为人工林的合理经营管理提供依据。

【Abstract】 Casuarina forest is the best in China’s southeast coastal shelterbelt fixing tree species, and is a good green trees all around. At present the studies focus on Casuarina in biomass, productivity, caloric values of each component, the caloric values and community structure of energy distribution and so on, the community structure and population ecology of small studies. Through field investigation, analysis of state-owned forest farms, Changle City, Cape Casuarina niche, distribution pattern, population structure and dynamics characteristics, the purpose is to understand the natural variation of Casuarina equisetifolia, Casuarina shelterbelt so as to provide scientific basis for rational management .To 400m2 for the sampling level, the use of variance ratio test, the percentage of co-occur, association coefficient, point correlation coefficient and chi-square testing of the main tree populations of association. The results showed that:It Was based on survey data to analyze the structural characteristics of Casuarina species dynamics, use "Space instead of Time," "horizontal derive vertical" approach in the preparation of Casuarina species in the specific life table, population survival curve was drawn,mortality rate curve and function analysis with four variable of population dynamics, and finally to spectral analysis. The results showed that: Casuarina survival curve should belong to Deevey-Ⅲtype, the early mortality rate of Casuarina species, the curve slope of the larger environment, the choice of intensity of a great screen, but only then with age, environmental screening of the selection intensity weakened, the lower the mortality rate of Casuarina, sapling stage of the transition phase to the relative balance of nutrition, survival curves tended to be stable, there are two peaks of Casuarina species mortality, respectively, in the first age classⅠ~Ⅱ, the firstⅧ~ⅨAge-class stage. Population viability analysis showed that the monotonic decline of Casuarina species survival function, cumulative mortality function is a monotonous rising, infant mortality rate shows a very high Casuarina species, grow into, the population becomes stable. Pinus species survival curve should belong to Deevey-Ⅱtype, indicating that pine mortality in all age the same population, the firstⅥ~Ⅶpopulation age class pine mortality peak value. Spectral analysis showed that: Casuarina species, Pinus species time series sufficient to show the length of the basic cycle, and the stand has reached a mature stage and can show significant fluctuations inherent cycle length.According to the plot of the actual situation and needs, site of tree height divided by 10 (0, +∞] to study the population structure and the high failure rate between stages. The results show that: Casuarina species in all high-level quantitative statistics, to all plots in the number of 1 to a maximum height level, reached 9578, accounting for survey 40.70% of total strain tree, decreases with each subsequent high-level trends, pine population structure of 6 high proportion of high-level the largest, reaching 38.96%. Casuarina sectionⅡ~Ⅲa high degree of instability of the highest level reached 69.7450%, pine forest to young forest stages in the population aged between failure rate level is basically negative, indicating that young pine forest compared the number of individuals of other ages to be a lot less.Based on actual survey data, using C, I, I &, PAI, Ca degree index and the Cluster Iwao equation Casuarina coastal population distribution pattern has been systematically studied, and compared the changes in the situation of sampling scales. The results showed that: the spatial distribution of Casuarina showed aggregated distribution, and Casuarina in 1600m2 sampling unit, the strongest aggregation, which may be due to various factors affect the population distribution of a certain scale, easy to form in the coupling, if beneficial population growth, population size of individual easily gathered in this growth. Meanwhile, the article also under Iwao’s M and the regression equation to calculate the density of Casuarina and allow different theoretical sampling error of area under. This study investigated the population density was 3~8 Casuarina plants/50m2, according to theoretical calculation of sample size should be taken at least 138 plots, the actual sample of this research plots the course of a few samples up to 256, therefore, this study The number of samples required is far greater than theoretical sampling area, measured in this study shows for the aggregated distribution of Casuarina is to be believed, the number of samples to achieve the accuracy requirements.Based on actual survey data, to the important value of species as a resource position on the performance characteristics, quantitative analysis of the main tree species Casuarina communities niche breadth, niche similarity, and niche overlap. The results showed that: Casuarina maximum niche breadth, in the community in an absolutely dominant position, largely because of its wide adaptability, and pine and Acacia auriculiformis smaller niche breadth; community in three major populations similarity between the proportion of value is not too high, although a certain degree of niche overlap, but overall remains low, and competition among species within communities are not very keen. As a result, further research can be used as Casuarina Coastal community structure, dynamics and interspecific relations.Scaling per tree diameter at breast height obtained by the tree to calculate the importance of higher numerical value, and accordingly to calculate the Casuarina and Pinus, Acacia auriculiformis relationship between the species, the results show that: Casuarina and Pinus showed strong negative association, Casuarina and Acacia auriculiformis, Pinus and Acacia auriculiformis between the existence of a weak positive association, on the whole, three kinds of coupling between the weak trend, indicating instability of the community, still in successional stages.Application of the improved model description of population growth, the specific analytic have four parameters, K, C, a,θ, the solution in the parameter when a predetermined initial value,θ= 1, this translated into population growth. Space units for the diameter of the temporal relationship between Casuarina species corresponding to the base area of values, a modified simplex method to establish population-based area of Casuarina Logistic growth model and the model parameters were optimized, and finally got Casuarina species .The intrinsic growth rate of 0.5884.Through the measured data, the density effect on the Casuarina species and natural thinning law, this paper select the average diameter, average tree basal area (g) and total stand basal area (G) as indicators of body size, to represent the tree line the relationship between tree and tree size. The results showed that: Casuarina tree population density and the relationship between the size of population density on the stand of Casuarina that the average diameter at breast height, average tree basal area, total stand basal area were there significant role. Among the various models fitted to model (41) was the best, and a significant regression effect. Therefore, management of Casuarina forest, you must attach proper importance to the stand density control and management, at the same time, this is for the plantation management to provide a reasonable basis.

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