永安市半天然马尾松阔叶混交林的树种组成与多样性

Species Composition and Diversity of Semi-Natural Mixed Forest of Pinus massoniana and Broad-Leaved Trees in Yong’an

【目的】揭示半天然马尾松阔叶混交林特别是其中天然更新阔叶林木的树种组成与多样性特征,为该类型林分的经营利用提供科学依据。【方法】在福建省永安市岭头村半天然马尾松阔叶混交林中设置1块50 m×160 m样地,将样地划分为80个10 m×10 m样方,对样方乔木层和灌木层进行每木调查,在样地内设置128个2 m×2 m草本层小样方进行草本植物调查。采用最大受光面法将乔木层划分为第Ⅰ亚层(受光层)和第Ⅱ亚层(非受光层),运用重要值及常用生物多样性指标分析乔木层(包括第Ⅰ亚层和第Ⅱ亚层)和灌木层的树种组成与多样性。【结果】乔木层、灌木层、草本层的物种丰富度分别为47、109和56;乔木层的Shannon-Wiener指数、均匀度和生态优势度分别为2.93、0.53和0.26;乔木层密度为2686株·hm^-2,其中灌木树种仅有9种,密度为28株·hm^-2,总重要值为1.58%;乔木层所有树种中,重要值排前5位的为马尾松(37.87%)、杉木(16.85%)、拟赤杨(10.40%)、檫木(7.01%)和木荷(4.91%);最大受光面的高度为12.6 m;第Ⅰ亚层的物种丰富度、Shannon-Wiener指数、均匀度和生态优势度分别为23、1.80、0.40和0.47,第Ⅰ亚层所有树种中,重要值排前5位的为马尾松(55.49%)、拟赤杨(13.38%)、檫木(10.69%)、杉木(9.04%)和丝栗栲(2.00%);第Ⅱ亚层的物种丰富度、Shannon-Wiener指数、均匀度和生态优势度分别为45、3.17、0.77和0.23,重要值排前5位的为杉木(38.84%)、拟赤杨(10.73%)、木荷(9.21%)、赛山梅(8.29%)和丝栗栲(4.26%);灌木层的Shannon-Wiener指数、均匀度和生态优势度分别为4.44、0.65和0.08,层内林木密度高达9651株·hm-2,其中灌木树种的密度仅为3143株·hm^-2、重要值仅占28.23%,层内所有树种中,重要值排前5位的为杉木(15.47%)、赛山梅(11.10%)、细枝柃(7.84%)、丝栗栲(5.75%)和拟赤杨(5.61%);草本层中草本植物株数占比为37.90%。【结论】半天然马尾松阔叶混交林已形成多树种混交的复层异龄林结构,乔木层、灌木层和草本层均具有较高的物种丰富度。人工马尾松是乔木层的优势种,天然更新的阔叶树以拟赤杨、檫木、木荷和赛山梅等为主,层内阔叶树的树种组成与多样性已接近相近年龄的人促阔叶林。第Ⅰ、Ⅱ亚层物种丰富度分别为23和45,第Ⅰ亚层中马尾松占据绝对优势,第Ⅱ亚层中杉木的重要值最大。灌木层内大多为乔木幼树,草本层中草本植物较少。

【Objective】The paper was intended to reveal the species composition and diversity characteristics of semi-natural mixed forest of Pinus massoniana and broad-leaved trees, especially the characteristics of the naturally regenerated broad-leaved trees, aimed to provide a scientific basis for the management and utilization of this type of forest.【Method】 A 50 m×160 m plot was set up in semi-natural mixed forest of Pinus massoniana and broad-leaved trees in Lingtou village, Yong’an municipality, Fujian Province. The plot was divided into 80 10 m×10 m quadrats, then the arbor and shrub layer of each quadrat were investigated. 128 small quadrats of 2 m×2 m were set up in the plot for the investigation of the herb layer. By using maximum light receiving plane (MLRP) method, the arbor layer was divided into two sub-layers, called sub-layer Ⅰ (light receiving layer) and sub-layer Ⅱ (non-light receiving layer). Then, the tree species composition and diversity of arbor layer (including the sub-layer Ⅰ and Ⅱ) and shrub layer were analyzed by importance value and several commonly used diversity indices. 【Result】The species richness of arbor layer, shrub layer and herb layer were 47, 109, and 56. The Shannon-Wiener index, evenness index and dominance index of arbor layer were 2.93, 0.53 ,and 0.26, respectively. The density of arbor layer was 2 686 per hectare, and there were only 9 shrub species, whose totaled density was 28 per hectare and importance value was 1.58%. Among all the species in the arbor layer, the top five of importance values were as follows: Pinus massoniana (37.87%), Cunninghamia lanceolata (16.85%), Alniphyllum fortunei (10.40%), Sassafras tzumu (7.01%) and Schima superba (4.91%). The height of maximum light receiving plane was 12.6 m. The species richness, Shannon-Wiener index, evenness index ,and dominance index of sub-layer Ⅰ were 23, 1.80, 0.40, and 0.47, respectively. In sub-layer Ⅰ, the top five of importance values were P. massoniana (55.49%), A. fortunei (13.38%), S. tzumu (10.69%), C. lanceolata (9.04%), and C. fargesii (2.00%). The species richness, Shannon-Wiener index, evenness index and dominance index of sub-layer Ⅱ were 45, 3.17, 0.77and 0.23, respectively, and the top five of importance values in this sub-layer were C. lanceolata (38.84%), A. fortunei (10.73%), S. superba (9.21%), Styrax confusus (8.29%) and C. fargesii(4.26%).The Shannon-Wiener index, evenness index and dominance index of shrub layer were 4.44, 0.65 ,and 0.08, respectively. The density of shrub layer was as high as 9 651 per hectare, and the density and the total importance values of shrubs were only 3 143 per hectare and 28.23%, respectively. Among all the species in shrub layer, the top five of importance values were C. lanceolate (15.47%), S. confuses (11.10%), C. fargesii (5.75%), Eurya loquaiana (7.84%) and A. fortunei (5.61%);the number of herbaceous plants counts 37.90% in the herb layer. 【Conclusion】The semi-natural mixed forest of P. massoniana and broad-leaved trees have formed a multi-stories mixed uneven-aged structure,the arbor layer, shrub layer and herb layer all have high species richness. The arbor layer was dominated by P. massoniana;and the majority of the naturally-regenerated trees were A. fortunei, S. tzumu, S. superba and S. confusus. The species composition and diversity of the naturally regenerated broad-leaved trees in the arbor layer were close to the broad-leaved forest with regeneration promoted by artificial measures at similar age. The species richness of sub-layer Ⅰ and Ⅱ were 23 and 45, respectively, P. massoniana had an absolute advantage in the sub-layer Ⅰ, and C. lanceolata had the largest importance value in the sub-layer Ⅱ. The majority of the shrub layer were saplings, and there were few herbaceous plants in the herb layer.