Structure and species composition of novel forests dominated by an introduced species in northcentral Puerto Rico
Structure and species composition of novel forests dominated by an introduced species in northcentral Puerto Rico
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波多黎各中北部以引进物种为主的新型森林的结构和物种组成
作者：
Oscar J. Abelleira Martínez;M. A. Rodríguez;I. Rosario;Nataly Soto;A. López;A. Lugo
非洲郁金香Spathodea campanulata Beauv.，是一个引进种形成新的森林类型在波多黎各。这些森林是在砍伐森林、农业使用和土地废弃后自然形成的，其生态特征存在许多问题。在9个以黄杉为主的次生林中，分别采集了胸径≥10、≥2.5 ~<10和<2.5cm的大树、小树和幼龄树的结构和物种组成。分布于波多黎各中北部的冲积、喀斯特和火山底质上。S.钟花林结构之间的基板。在总共发现的79个物种中，有17个是引进的。喀斯特森林和冲积层森林的全球物种丰富度分别最高和最低。物种丰富度增加，从大到小，在大多数网站的幼龄树，但更多的喀斯特。引进物种的百分比呈负相关的物种丰富度的树木大小类的所有基板类型。S.在所有基质类型中，乔木大小级中的钟形花分别在冲积和火山立地中最高和最低，并从大到小到幼龄树降低。物种丰富度S.在同等基质上，钟花林的土壤含水量低于天然林。虽然土地利用历史影响组成，在S。钟形林似乎与遗址所在的地质基质相对应。在波多黎各，一个名为campanulata的项目在废弃的农业和牧场上恢复森林结构和本土树种。对这些新森林的管理应将其视为资源，因为自然过程有可能使其更加多样化。
The African tulip tree, Spathodea campanulata Beauv., is an introduced species forming novel forest types in Puerto Rico. These forests develop naturally after deforestation, agricultural use and land abandonment, and there are many questions as to their ecological characteristics. We sampled structure and species composition of large, small, and juvenile trees (≥10, ≥2.5 to <10, and <2.5 cm diameter at breast height, respectively) in nine secondary forests dominated by S. campanulata on alluvial, karst, and volcanic substrates in northcentral Puerto Rico. No differences were found in S. campanulata forest structure between substrates. Of a total of 79 species found, 17 were introduced. Forests on karst and alluvium had the highest and lowest global species richness, respectively. Species richness increased from large to small to juvenile trees in most sites, but more so on karst. The percentage of introduced species was inversely related to species richness of tree size classes on all substrate types. The dominance of S. campanulata in the large tree size class was highest and lowest in alluvial and volcanic sites, respectively, and decreased from large to small to juvenile trees on all substrate types. Species richness of S. campanulata forests is lower than that of native forests on equivalent substrates. Although land use history affects composition, the juvenile tree species established in S. campanulata forests seems to correspond to the geological substrate were sites are found. This study shows S. campanulata restores forest structure and native tree species on abandoned agriculture and grazing lands in Puerto Rico. Management of these novel forests should consider them as resources were natural processes have the potential of making them more diverse.