Vilà Montserrat, Vayreda Jordi, Gracia Carles, Ibáñez Joan Josep
Centre de Recerca Ecològica i Aplicacions Forestals, 08193 Bellaterra, Barcelona, Spain.
Oecologia. 2003 Apr;135(2):299-303. doi: 10.1007/s00442-003-1182-y. Epub 2003 Feb 13.
Recent experimental advances on the positive effect of species richness on ecosystem productivity highlight the need to explore this relationship in communities other than grasslands and using non-synthetic experiments. We investigated whether wood production in forests dominated by Aleppo pine (Pinus halepensis) and Pyrenean Scots pine (Pinus sylvestris) differed between monospecific and mixed forests (2-5 species) using the Ecological and Forest Inventory of Catalonia (IEFC) database which contains biotic and environmental characteristics for 10,644 field plots distributed within a 31,944 km(2) area in Catalonia (NE Spain). We found that in Pyrenean Scots pine forests wood production was not significantly different between monospecific and mixed plots. In contrast, in Aleppo pine forests wood production was greater in mixed plots than in monospecific plots. However, when climate, bedrock types, radiation and successional stage per plot were included in the analysis, species richness was no longer a significant factor. Aleppo pine forests had the highest productivity in plots located in humid climates and on marls and sandstone bedrocks. Climate did not influence wood production in Pyrenean Scots pine forests, but it was highest on sandstone and consolidated alluvial materials. For both pine forests wood production was negatively correlated with successional stage. Radiation did not influence wood production. Our analysis emphasizes the influence of macroenvironmental factors and temporal variation on tree productivity at the regional scale. Well-conducted forest surveys are an excellent source of data to test for the association between diversity and productivity driven by large-scale environmental factors.
近期关于物种丰富度对生态系统生产力产生积极影响的实验进展，凸显了在除草地之外的群落中以及使用非人工合成实验来探究这种关系的必要性。我们利用加泰罗尼亚生态与森林资源清查（IEFC）数据库，调查了以阿勒颇松（Pinus halepensis）和比利牛斯山苏格兰松（Pinus sylvestris）为主的森林中，单种林和混交林（2 - 5种）之间木材产量是否存在差异。该数据库包含了西班牙东北部加泰罗尼亚地区31,944平方公里范围内10,644个实地样地的生物和环境特征。我们发现，在比利牛斯山苏格兰松林中，单种样地和混交样地的木材产量没有显著差异。相比之下，在阿勒颇松林中，混交样地的木材产量高于单种样地。然而，当将每个样地的气候、基岩类型、辐射和演替阶段纳入分析时，物种丰富度不再是一个显著因素。阿勒颇松林在湿润气候以及泥灰岩和砂岩基岩上的样地产量最高。气候对比利牛斯山苏格兰松林的木材产量没有影响，但在砂岩和固结冲积物上产量最高。对于这两种松林，木材产量与演替阶段呈负相关。辐射对木材产量没有影响。我们的分析强调了宏观环境因素和时间变化对区域尺度树木生产力的影响。精心开展的森林调查是检验由大规模环境因素驱动的多样性与生产力之间关联的绝佳数据来源。
