Abstract Detail

Ecology

Martini, Francesco [1], Xia, Shangwen [2], Manage Goodale, Uromi [1].

Forest regeneration in a subtropical forest: factors shaping seedling community along elevation.

Understanding the mechanisms that govern forest regeneration is important to predict future scenarios under climate change and for developing better conservation strategies. Elevation plays a significant effect on plants recruitment and their range shifts under climate. Microsite conditions and seed production also change with elevation, influencing species changes in distribution and seed persistence in the soil. Most studies that assess elevation effects on recruitment are located in the northern temperate zone, some in the tropics, but only few the subtropics. Moreover, rarely more than two factors affecting recruitment are investigated together. The aim of this study was to investigate the combined effect of elevation, microsite conditions and herbivory on the seedling community in a subtropical forests of Guangxi, southern China. A total of 5 one-ha plots, covering an elevation gradient of ca. 500 meters (1400, 1500, 1550, 1750, 1850 m asl), were used. Each plot included 24, 1m² seedling quadrats, where all woody seedlings were measured and monitored for one year. Eight additional 1 m² seedling quadrats were surrounded with a net to exclude browsing from bigger animals. Edaphic, topographic, soil nutrients and water content, and canopy openness data were also measured. A total of 1150 seedlings were monitored, for a mean density of 7.19 seedlings per square meter. The highest abundance was found at 1550 m, and the lowest at 1850 m. The maximum number of seedlings per quadrat was 112, while 8% of the quadrats didn't show any seedling at any time. Seedling density and species diversity showed large variation within elevations between the seedling plots. The highest total recruitment was found between June and August, while the highest mortality was registered between November and January. Seedling growth rate was higher during May-June period. In terms of browsing herbivory, no evidence of browsing animals was found through the enclosed vs. open seedling quadrats, suggesting that the wildlife browsing community might be scarce. In terms of insect herbivory instead, leaves presented an average damage of 14% across two seasons, with significant differences between the two. This result is higher than what found in other studies, which indicate that the insect community, contrarily to the browsing one, is rich. However, the intensity of foliar damage didn't show any effect on seedling growth.

1 - Guangxi University, Forestry College, Guangxi Key Laboratory of Forest Ecology and Conservation, 100, DaXueDongLu, Nanning, GX, 530000, China
2 - Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Soil Ecology Group, Menglun, YU, 666303, China

Keywords:
Forest regeneration
Elevation
Subtropical forest
Seedling.

Presentation Type: Oral Paper
Session: 7, Ecology Section - Community Interactions and Responses
Location: 106/Mayo Civic Center
Date: Monday, July 23rd, 2018
Time: 9:00 AM
Number: 7003
Abstract ID:522
Candidate for Awards:Ecological Section Best Graduate Student Paper