Data from: Long-term changes in liana loads and tree dynamics in a Malaysian forest

The importance of lianas through time and their effect on tree reproduction are evaluated for the first time in a Southeast Asian Dipterocarp forest. We quantified flower and seed production by lianas and trees for 13 years, assessed liana loads in the crowns of all trees larger than 30 cm in diameter at breast height (1.3 m) in 2002 and 2014, and assessed levels of reproduction for the same trees during a strong general flowering event in 2014 for the 50-ha forest dynamics plot at the Pasoh Forest Reserve, Malaysia. General flowering refers to synchronous reproduction by hundreds of plant species at irregular, multiyear intervals and only occurs in Southeast Asian Dipterocarp forests. Overall, lianas were present in 50% of tree crowns and comprised 31% of flower production and 46% of seed production. Lianas reduced growth, survival, and reproduction by their host trees. Lianas were less frequent in canopy-emergent trees, Dipterocarps comprised a disproportionately large proportion of canopy emergents, and, as a consequence, lianas were less frequent in Dipterocarps than in trees from other plant families. Lianas infested the crowns of significantly fewer trees in 2014 (47.9%) than in 2002 (52.3%); however, the decrease was restricted to trees with the lightest liana loads and sample sizes and statistical power were enormous. Lianas comprised a stable proportion of flower production and a highly variable proportion of seed production from 2002 through 2013. We conclude lianas have a huge impact on trees in this forest and were a stable component of the forest between 2002 and 2014. The emergent habit and associated ability to avoid lianas might contribute to the success of the Dipterocarpaceae.

本研究首次在东南亚龙脑香林（Dipterocarp forest）中，评估了藤本植物（lianas）随时间变化的生态重要性及其对树木繁殖的影响。我们针对马来西亚巴索森林保护区内50公顷的森林动态监测样地，开展了为期13年的量化研究，统计了藤本植物与树木的花、种子产量；分别于2002年与2014年，对所有胸径（距地面1.3米处）大于30厘米的树木冠层内的藤本负荷量进行了调查评估，并在2014年一次强烈的普遍开花事件期间，针对该样地内的同批树木评估了其繁殖水平。普遍开花指数百种植物以不规则的多年间隔同步进行繁殖的现象，该现象仅存在于东南亚龙脑香林中。总体而言，50%的树木冠层中存在藤本植物，其花产量占总花产量的31%，种子产量占总种子产量的46%。藤本植物会降低宿主树木的生长速率、存活概率与繁殖能力。冠层顶层乔木的藤本侵染率更低；而龙脑香科植物在冠层顶层乔木中占比极高，因此相较于其他植物科属的树木，龙脑香科树木的藤本侵染率显著更低。2014年受藤本侵染的树木比例（47.9%）显著低于2002年的52.3%；但该下降仅局限于藤本负荷最轻的树木，且本研究的样本量与统计功效均十分充足。2002年至2013年间，藤本植物的花产量占比始终保持稳定，而种子产量占比则呈现高度波动。本研究得出结论：藤本植物对该林分的树木具有极强的生态影响，且在2002年至2014年间始终是森林群落的稳定组成部分。冠层顶层生长习性及其附带的避藤能力，可能是龙脑香科（Dipterocarpaceae）植物得以成功繁衍的重要原因。