吉林蛟河近熟林树种多样性格局组建机制研究

Structuring mechanism of tree species diversity pattern in a near-mature forest in Jiaohe

植物种在群落多样性格局组建过程中所起的作用一直是生态学重点关注的问题。2010年在吉林蛟河建立面积为21.12 hm2的近熟林监测样地,样地中记录到DBH≥1 cm木本植物32 405株,共计50种木本植物。利用单物种-面积关系模型分析了样地内30种木本植物对局域群落多样性格局的影响,利用完全空间随机化模拟计算植物对局域多样性促进或抑制的显著性程度。研究结果表明：1）由于ISAR模型没有考虑竞争的非对称性,在相同取样面积下,同一树种的m ISAR值普遍低于ISAR值。不同树种的m ISAR曲线更加分散、区分度更为明显,且具有明显的尺度依赖性。2）在0-50 m空间尺度上,簇毛槭、黑樱桃、翅卫矛、稠李、大果榆、花楷槭、毛榛和青楷槭为多样性促进种;水榆为中性种;红松、色木槭、胡桃楸在绝大多数空间尺度上表现为抑制种;其余树种绝大多数在小尺度上表现为促进种。3）在中小尺度上,促进种决定了局域群落多样性格局组建;在较大尺度上,促进种和中性种共同作用于群落多样性格局的组建,并且随机过程的影响相对更强。因此,促进种和抑制种所代表的确定性过程与中性种所代表的随机过程共同作用于森林群落多样性格局构建过程,并且二者起作用的空间尺度不同。

The effect of plant species on the community diversity pattern has long been a key issue in ecology.A 21. 12 hm2near-mature forest plot was established in Jiaohe of Jilin Province. Totally,32 405 woody individuals with diameter at breast height（ DBH） ≥1 cm belonging to 50 woody species were recorded.Individual species-area relationship（ ISAR） was used to quantify the effects of 30 woody species on local community diversity pattern. Complete spatial randomness simulation was adopted to calculate the significance of facilitation or suppression. The results show that： 1） ISAR value is generally higher than mI SAR value for the same tree species in the same sampling area, because ISAR model ignores asymmetry of competition. The mI SAR curves for different tree species are more dispersed,and have higher differnentiation degree and obvious scale dependence. 2） At 0- 50 m scales,Acer barbinerve,Cerasus maximowiczii,Euonymus macropterus,Padus racemosa,Ulmus macrocarpa,Acer ukurunduense,Corylus mandshurica and Acer tegmentosum are diversity accumulators while Sorbus alnifolia is a neutralspecies. Pinus koraiensis,Acer mono and Juglans mandshurica are diversity repellers at most spatial scales. Most of the other tree species act as diversity accumulators at small scales. 3） Diversity accumulators dominate the community diversity pattern at the small and medium scales. Diversity accumulators and neutrals jointly affect the structuring of the community diversity pattern at large scales,and the influence of stochastic process is relatively stronger. Therefore,deterministic process represented by accumulators and repellers and stochastic process represented by neutral species collectively determine the structuring processes of community diversity pattern,and the effects of two processes differ at different spatial scales.