Abstract Detail

Physiological Section

Goodale , Uromi Manage [1], Cao, Kunfang [2], Wen, Bin [3].

Habitat specialization of tropical figs through germination cueing and seedling emergence: a comparative study of hemiepiphytes and terrestrial species.

Some Ficus species in the family Moraceae start their life as epiphytes and produce roots that descned to the ground. Known as hemiepiphytes theses plants are generally exposed to higher irradiances and temperatures and avoide hazards such as flooding, fire damage and herbivore damage by terrestrial anaimals, which has a greater impact on their terrestrial counterparts. However, they are at a disadvantage due to water and nutrient deficiencies as well as mechanical dislodging. Here we investigated the response to temperature and water availability in 26 Ficus species and comapred their seed germination, defined as 2 mm radical emergence, seedling emergence and seedling establishment in soil. Seeds of each species were subjected to six 10/14 day and night temperature fluctuations from 10/20 °C to 30/40 °C with 5 °C increments and each temperature treatment received three water availability conditions that represent soil water availability in the rainy season, cool dry seasons and hot dry season in tropical Xishuangbanna, Yunnan, China, where these experiments were carried out. We found that in all species, seedling emergence, defined as cotyledon expansion, was more sensitive to temperature extremes compared to seed germination. There was no difference in the response to water availability between the hemiepiphytic and terrestial species. Ficus seeds of this study, which were >2 mm were able to germinate well under all water conditions but seedling emergence was greater in hemiepyphytic species. Seedling establishment success was comparatively lower in terrestrial species when germinated seedlings were transferred to soil, indicating higher vigor of hemiepiphytic species. We conclude that under fluctuating temperatre and variable water availability seedling emergence rather than germination responses might contribute to differences in Ficus habitat preferences. 

1 - Xishuangbanna Tropical Botanical Garden, Chinese Academy Of Sciences, Menglun, Mengla, Yunnan, 666303, P.R. China
2 - Guangxi University, College of Forestry, Guangxi University, College of Forestry, No. 100 Daxue Road, Nanning, 530004, P.R. China
3 - Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Key Laboratory of Tropical Forest Ecology, Seed Conservation Bank, Menglun, Mengla, Yunnan, 666303 , P.R. China

Keywords:
Habitat specialization
germination cueing
Seedling emergene
Ficus
Hemiepiphytes
Climate change.

Presentation Type: Oral Paper:Papers for Sections
Session: 42
Location: Pines South/Boise Centre
Date: Wednesday, July 30th, 2014
Time: 3:00 PM
Number: 42007
Abstract ID:864
Candidate for Awards:None