Data from: Microtopographic specialization and flexibility in tropical peat swamp forest tree species

Tropical tree species distributions are determined by a wide range of biotic and abiotic factors, including topography and hydrology. Tropical peat-swamp forests (TPSFs) are characterized in part by small-scale variations in topography (“hummocks” and “hollows”) that create distinct microhabitats and thus may contribute to niche diversification among TPSF tree species. Using tree elevations calibrated to daily peat water levels collected using a data logger and a permutation test, we evaluated topographical microhabitat preferences for 21 tree species in a relatively undisturbed TPSF in Central Kalimantan, Indonesia to determine whether these species show preferential association with hummocks or hollows, and to quantify the prevalence of microhabitat specialization among them. Only one species, Tetractomia tetrandrum, emerged as a hollow specialist, with no hummock specialists among the species tested. The remaining 20 species, including Psydrax dicoccos, which had the lowest mean observed elevation, and Maasia hypoleuca, which had the highest mean observed elevation, showed no clear microtopographic preference. This suggests that many TPSF species may be resilient to the natural hydrologic variations that occur in relatively intact peat-swamp forests. Such studies of microtopographic preferences of tree species in TPSF and other wetland forest ecosystems can inform selection of tree species for reforestation projects, and potentially also provide information on how future climate change may impact these habitats and their resident tree species.

热带树木物种的分布由诸多生物与非生物因子共同决定，涵盖地形与水文条件。热带泥炭沼泽森林（Tropical Peat-swamp Forests, TPSFs）的部分特征为存在小规模地形变异，即“土丘（hummocks）”与“洼坑（hollows）”，此类地形差异可形成独特的微生境，进而可能推动TPSF内树木物种的生态位分化。本研究借助经数据记录仪采集的每日泥炭水位校准得到的树木海拔数据，并结合置换检验（permutation test），对印度尼西亚加里曼丹中部一片相对未受干扰的TPSF内的21个树木物种的地形微生境偏好进行了评估，旨在明确这些物种是否偏好土丘或洼坑生境，并量化其中微生境特化现象的普遍程度。仅1个物种——四蕊四棱木（Tetractomia tetrandrum）——被确定为洼坑特化物种，受试物种中未发现土丘特化物种。剩余20个物种（包括平均观测海拔最低的Psydrax dicoccos，以及平均观测海拔最高的Maasia hypoleuca）均未表现出明确的微地形偏好。这表明多数TPSF物种可耐受相对完整泥炭沼泽森林中存在的自然水文波动。此类针对TPSF及其他湿地森林生态系统中树木物种微地形偏好的研究，可为造林项目的树种选择提供科学参考，同时也有望为未来气候变化如何影响这些生境及其栖息的树木物种提供理论依据。