Chalermsri Anussara, Ampornpan La-Aw, Purahong Witoon
Prasarnmit Demonstration School (Elementary), Faculty of Education, Srinakharinwirot University, Bangkok 10110, Thailand.
Department of Biology, Faculty of Science, Srinakharinwirot University, Bangkok 10110, Thailand.
Plants (Basel). 2020 Oct 20;9(10):1391. doi: 10.3390/plants9101391.
Human activity negatively affects the sustainability of forest ecosystems globally. Disturbed forests may or may not recover by themselves in a certain period of time. However, it is still unclear as to what parameters can be used to reasonably predict the potential for self-recovery of human-disturbed forests. Here, we combined seed rain, soil seed bank, and seed emergence experiments to evaluate the potential for self-recovery of a highly disturbed, tropical, mixed deciduous forest in northeastern Thailand. Our results show a limited potential for self-recovery of this forest due to low seedling input and storage and an extremely high mortality rate during the drought period. There were 15 tree species of seedlings present during the regeneration period in comparison with a total number of 56 tree species in current standing vegetation. During the dry season, only four tree seedling species survived, and the highest mortality rate reached 83.87%. We also found that the correspondence between the combined number of species and composition of plant communities obtained from seed rain, soil seed bank, and seedling emergence experiments and the standing vegetation was poor. We clearly show the temporal dynamics of the seed rain and seedling communities, which are driven by different plant reproductive phenology and dispersal mechanisms, and drought coupled with mortality. We conclude that this highly disturbed forest needs a management plan and could not recover by itself in a short period of time. We recommend the use of external seed and seedling supplies and the maintenance of soil water content (i.e., shading) during periods of drought in order to help increase seedling abundances and species richness, and to reduce the mortality rate.
人类活动对全球森林生态系统的可持续性产生负面影响。受到干扰的森林在一定时期内可能会自行恢复，也可能不会。然而，目前仍不清楚哪些参数可用于合理预测受人类干扰森林的自我恢复潜力。在此，我们结合种子雨、土壤种子库和种子萌发实验，评估泰国东北部一片受到高度干扰的热带落叶混交林的自我恢复潜力。我们的结果表明，由于幼苗输入和储存量低以及干旱期间极高的死亡率，这片森林的自我恢复潜力有限。在再生期出现了15种树苗，而现存植被中的树种总数为56种。在旱季，只有4种树幼苗存活，最高死亡率达到83.87%。我们还发现，从种子雨、土壤种子库和幼苗萌发实验中获得的植物群落物种总数和组成与现存植被之间的对应关系较差。我们清楚地展示了种子雨和幼苗群落的时间动态，它们受到不同植物繁殖物候和传播机制以及干旱和死亡率的驱动。我们得出结论，这片受到高度干扰的森林需要一个管理计划，短期内无法自行恢复。我们建议使用外部种子和幼苗供应，并在干旱时期保持土壤含水量（即遮荫），以帮助增加幼苗数量和物种丰富度，并降低死亡率。
