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沙质海岸空间梯度上环境差异较大,黑松(Pinus thunbergii)在长期的适应过程中树冠结构变化也很大。为揭示黑松树冠结构与环境间的适应机制,在山东省胶南市灵山湾国家森林公园距海岸线0-50、200-250和400-450m梯度内各设置1个样带,记为带I、带II、带III,采用枝构型的理论和方法,对黑松的分枝格局进行了研究,并采用模拟自然风法测定了黑松枝条的抗风折能力。结果表明:1)在海岸梯度上黑松分枝格局差异较大,随着距离海岸越来越远,黑松各级枝的分枝长度、总体分枝率均逐渐增大,而枝径比和逐步分枝率逐渐减小,各级分枝角度表现为带I>带III>带II。2)带I树冠背风面与迎风面相比,分枝长度、分枝角度、分枝数量、枝条干枯率分别是迎风面的1.62、1.38、2.65和0.59倍,随着距离海岸越来越远,这种不对称性逐渐减弱,至带III树冠基本对称。3)海风是影响带I分枝角度偏转、枝条干枯和冠型不对称现象的主要原因。4)带III枝条的抗风折能力高于带I,且两个样带模拟风速与枝条所承受的拉力之间的关系均符合逻辑斯蒂方程,相关系数R2均达0.97以上。该研究揭示了不同海岸梯度上黑松分枝格局的形成机制及其抗风折能力,可为沿海黑松防护林的合理经营提供科学依据。
The spatial variability of sandy coast spatial variability is quite different, and the crown structure of Pinus thunbergii also changes greatly during long-term adaptation. In order to reveal the adaptation mechanism between crown structure and environment of Pinus thunbergii, one transect was set in each gradient of 0-50, 200-250 and 400-450m from coastline in Lingshan Bay National Forest Park, Jiaonan City, Shandong Province, Belt II, Belt III, the branch structure of the theory and methods used to study the branching pattern of Pinus thunbergii and simulated natural wind method was used to determine the anti-wind buckling capacity of black pine branches. The results showed as follows: 1) The branch pattern of Pinus thunbergii had a great difference on the coast gradient. As the distance from coast to coast increased, the branch length and total branch rate of all branches increased gradually, And gradual branching rate gradually decreased, the branches at all levels showed I> zone III> zone II. 2) Compared with the windward surface, the branch length, branching angle, number of branches and shoot dryness were 1.62, 1.38, 2.65 and 0.59 times, respectively. Compared with the windward side, This asymmetry gradually weakened, with the basic symmetry with III crown. 3) The sea breeze is the main reason that affects the deflection of branches with I branches, the dry branches and the crown-shaped asymmetry. 4) The anti-wind-break capacity of the branches with III is higher than that of the zone I, and the relationship between the simulated wind speed of the two transects and the tensile force suffered by the branches accords with the Logistic equation with the correlation coefficient R2 reaching above 0.97. The study revealed the formation mechanism of Pinus thunbergii branching pattern and its ability of anti-wind-break on different coastal gradients, which could provide a scientific basis for the rational management of coastal Pinus thunbergii shelter-forest.