African tropical tree database

We censused all trees greater than or equal to cm dbh in 50 ha of forest in Korup National Park, southwest Cameroon, in the central African coastal forest known for high diversity and endemism. The plot included 329,519 individuals and 493 species, but 128 of those taxa remain partially identified. Abundance varied over four orders of magnitude, from 1 individual per 50 ha (34 species) to Phyllobotryon spathulatum, with 26,741 trees; basal area varied over six orders of magnitude. Abundance patterns, both the percentage of rare species and the dominance of abundant species were similar to those from 50-ha plots censused the same way in Asia and Latin America. Rare species in the Korup plot were much less likely to be identified than common species: 42% of taxa with greater than 10 individuals in the plot were identified to species, compared to 95% of the abundant taxa. Geographic ranges for all identified species were gleaned from the literature and online flora. Thirteen of the plot species are known only from Korup National Park (all discovered during the plot census), and 39 are restricted to the Nigeria-Cameroon coastal zone. Contrary to expectation, species with narrow geographic ranges were more abundant in the plot than average. The small number of narrow endemics (11% of the species), many locally abundant, mitigates short-term extinction risk, either from demographic stochasticity or habitat loss. (Biodivers Conserv DOI 10.1007/s10531-006-9065-2)

我们对喀麦隆西南部科鲁普国家公园（Korup National Park）内50公顷森林中所有胸径（diameter at breast height, DBH）≥cm的树木开展了全面普查。该区域属于以极高物种多样性和特有性著称的中非沿海森林。本次普查样地共记录329519株个体，隶属于493个物种，但其中128个类群仅完成部分鉴定。物种多度的变化幅度跨越四个数量级，从每50公顷仅存1株的34个物种，到个体数达26741株的匙叶叶苞桐（Phyllobotryon spathulatum）；树木断面积的变化幅度更是跨越六个数量级。无论是稀有种占比还是优势种的优势度格局，本次样地的普查结果均与采用相同清查方法的亚洲及拉丁美洲50公顷样地的结果高度相似。科鲁普样地内的稀有种相较于常见种更难完成物种级鉴定：样地内个体数大于10的类群中，仅42%可鉴定至物种水平，而个体数丰富的类群这一鉴定比例可达95%。所有已鉴定物种的地理分布范围均通过文献及在线植物志汇编获取。本次样地记录的物种中，有13种仅见于科鲁普国家公园（均为本次普查期间首次发现的新种），另有39种仅分布于尼日利亚-喀麦隆沿海地带。与学界预期相悖的是，地理分布范围狭窄的物种在样地内的多度高于平均水平。这类狭域特有种仅占物种总数的11%，其中多数在当地种群较为繁盛，这一特征降低了它们因种群统计随机性或生境丧失而面临的短期灭绝风险。（《生物多样性保护》（Biodivers Conserv）DOI: 10.1007/s10531-006-9065-2）