Abstract Detail

Ecology

Castillo Diaz, Diana [1], Chen, Huayang [2], Harrison, Rhett [3], Wen, Bin [4], Manage Goodale, Uromi [5].

Assessment of seedling recruitment limitation among eight Ficus species in southern China.

In the age of unprecedented climate change and habitat loss, it is imperative that we gain a greater understanding of how forest regeneration occurs using field-based studies conducted in natural forests, especially for keystone species such as those in the genus Ficus. Generally known as figs, the genus Ficus, has more than 800 tropical and subtropical species, which have high cultural, horticultural, medicinal, and non-timber forest product value as well as ecological significance. However, recruitment limitation threatens their successful regeneration, constraining establishment of populations and consequently modifying forest dynamics, composition and diversity that could lead to the collapse of plant and animal communities. Here, I used eight, 1-ha long term monitoring plots, established along an elevation gradient (400 – 1850 m a.s.l.) in four transitional tropical - subtropical forests in Guangxi province, southern China. I assessed seedling recruitment limitation of four hemiepiphytic and four non-hemiepiphytic Ficus species through a seed addition experiment on the forest floor, which provided insights into seedling recruitment. We observed that Ficus regeneration process was highly limited (0.69 ± 0.01) throughout the subtropical landscape with greater germination in lower elevations. The strongest filtering effect was observed during seedling emergence. Higher elevation, greater canopy openness provided greater facilitation but drier and cooler soils being less conducive to seedling emergence, especially for hemiepiphytic species. Once emerged, fig seedlings were released from the environmental filters assessed here, yet, continued to face successively mortality during establishment and recruitment. Greater seed germination and seedling emergence on the ground observed in hemiepiphytes indicated that they may benefit from evolutionary traits, associated with canopy regeneration under water and temperature stress, even in terrestrial regeneration, but only at the early stages, as seedling establishment and recruitment was similar in both groups. Our results demonstrate that even when seeds are available, successful recruitment is limited by microsite conditions and growth form, through filtering mechanisms associated with the transition from seedling emergence to seedling establishment, and consequently affecting these species’ ecological interactions and forest dynamics.

1 - Daxuedonglu 100, Nanning, Guangxi, 45, 530005, China
2 - Institute Of Botany, The Chinese Academy Of Sciences, State Key Laboratory Of Vegetation And Environmental Change, No.20 Nanxincun, Xiangshan, Beijing, 100093, P.R. China, Beijing, 11, 100093, China
3 - World Agroforestry Centre, , East and Southern Africa Regional Office, Zambia, Luzaka, Africa
4 - Center for Integrative Conservation, Xishuangbanna Tropical Botanical
5 - Guangxi University, Plant Ecophysiology And Evolution Group, State Key Laboratory Of Conservation And Utilization Of Subtropical Agro-bioresources, College Of Forestry,, Daxuedonglu 100, Nanning, 530005, China

Keywords:
recruitment limitation
germination limitation
seedling emergence
seedling establishment
growth habit
elevation gradients
canopy openness
soil.

Presentation Type: Oral Paper
Session: ECO6, Ecology: Restoration and Conservation
Location: /
Date: Thursday, July 22nd, 2021
Time: 3:45 PM(EDT)
Number: ECO6004
Abstract ID:477
Candidate for Awards:Ecological Section Best Graduate Student Paper