Assessing the invasion risk of botanical garden's exotic threatened collections to adjacent mountain forests: A case study of Cibodas Botanical Garden

A primary objective of botanical gardens is to conserve threatened plant species from different regions and countries.However,such ex-situ conservation practices for exotic plant species may pose a significant plant invasion risks.In this study,we predict the naturalization probability of exotic threatened plant species of Cibodas Botanical Garden(CBG) collections based on leaf trait(specific leaf area,SLA) or as a function of invasion risk assessment scoring system(Tropical Weed Risk Assessment Protocol,TWRAP).We found that SLA and TWRAP were positively correlated with naturalization probability.The TWRAP model produced higher predictive probabilities with larger uncertainty compared to SLA model.Parmentiera cereifera and Burretiodendron hsienmu are two species that have highest naturalization probability based on SLA model.Chamaedorea oblongata has the highest naturalization probability based on TWRAP model.From practical and management point of view,we recommend the simultaneous use of SLA-based and TWRAP-based invasive species risk assessment to estimate the naturalization risk of exotic threatened collections of botanical gardens to adjacent mountain forests.Finally,given the important conservation value of threatened exotic collection of botanical garden,we need to be aware with the invasion risks of these species.The threatened condition of a plant species is not only caused by its natural characteristics but also may be caused(in fact mostly confounding with) by external disturbance either natural catastrophic or human related activities.Thus,a threatened species may not necessarily a noninvasive species outside their natural distribution ranges.

Leaf thickness and elevation explain naturalized alien species richness in a tropical mountain forest: A case study from Mount Gede-Pangrango National Park,Indonesia

Exotic plant invasion is one of the major causes of species extinction.In many contexts,mountainous forests are the last refuge for native species.There are several inventory studies conducted in mountainous and tropical forests in Indonesia.However,there are no studies yet on the factors that explain the abundance and richness of surveyed naturalized alien species.This study investigated whether the number of individuals and abundanceweighted species richness(AWR) of naturalized alien plant species in the hiking-trail of Mount GedePangrango National Park(MGPNP) forest area correlated with leaf traits(specific leaf area(SLA) and leaf thickness) and environmental factors(elevation,slope,and normalized difference vegetation index(NDVI)).We showed that leaf thickness and habitat elevation explained the AWR variations of naturalized alien species.We did not detect any important effect of leaf traits and environmental factors on the number of individuals per exotic species per plot.The influence of leaf thickness and habitat elevation indicates the important role of both biotic and abiotic factors on exotic species to develop a high species richness and become an invasive species in the tropical mountain forest ecosystem.

西双版纳布龙自然保护区勐宋片区附生维管植物多样性与分布特征（英文）

利用地面观测和单绳上树法初次对布龙自然保护区勐宋片区开展的附生维管植物调查表明：1）在6个样地77株宿主上（共调查96株乔木，占地约0．2ha），共有1756株、丛个体，隶属14科47属103种；相比世界其他区域，物种丰富度处于旧世界热带水平区间，高于温带，但明显低于新世界热带水平；2）兰科植物为最丰富的类群（60％），其次为蕨类植物（24％），其他类群占16％；3）垂直分布特征研究表明，距地面10～15m的中等高度带为物种最丰富的区间，约有51％的物种；0～5m高度带为个体数量最多的区间，共有约24％个体，揭示了除中等高度带以外的另一个重要附生生境；4）常见的绞杀型榕属植物未见，而半附生植物密脉鹅掌柴（Schefflera elliptica）和多蕊木（Tupidanthus calrlgtratus）数量较多。