Artigo
The community-level effect of light on germination timing in relation to seed mass: a source of regeneration niche differentiation
Registro en:
New Phytologist. Hoboken: Wiley-blackwell, v. 204, n. 3, p. 496-506, 2014.
0028-646X
10.1111/nph.12955
WOS:000343869000010
Autor
Zhang, Chunhui
Willis, Charles G.
Burghardt, Liana T.
Qi, Wei
Liu, Kun
Souza-Filho, Paulo Roberto de Moura [UNESP]
Ma, Zhen
Du, Guozhen
Resumen
Within a community, species may germinate at different times so as to mitigate competition and to take advantage of different aspects of the seasonal environment (temporal niche differentiation). We illustrated a hypothesis of the combined effects of abiotic and biotic competitive factors on germination timing and the subsequent upscale effects on community assembly. We estimated the germination timing (GT) for 476 angiosperm species of the eastern Tibetan Plateau grasslands under two light treatments in the field: high (i.e. natural) light and low light. We also measured the shift in germination timing (SGT) across treatments for all species. Furthermore, we used phylogenetic comparative methods to test if GT and SGT were associated with seed mass, an important factor in competitive interactions. We found a significant positive correlation between GT and seed mass in both light treatments. Additionally, small seeds (early germinating seeds) tended to germinate later and large seeds (late germinating seeds) tended to germinate earlier under low light vs high light conditions. Low light availability can reduce temporal niche differentiation by increasing the overlap in germination time between small and large seeds. In turn, reduced temporal niche differentiation may increase competition in the process of community assembly. Natural Science Foundation of China China Scholarship Council (CSC) Lanzhou Univ, State Key Lab Grassland Agroecosyst, Sch Life Sci, Lanzhou 730000, Gansu, Peoples R China Chinese Acad Sci, Northwest Inst Plateau Biol, Key Lab Adaptat & Evolut Plateau Biota, Xining 810008, Qinghai, Peoples R China Harvard Univ, Ctr Environm, Cambridge, MA 02138 USA Duke Univ, Dept Biol, Durham, NC 27708 USA Univ Estadual Paulista, Dept Bot, BR-13506125 Sao Paulo, Brazil Univ Estadual Paulista, Dept Bot, BR-13506125 Sao Paulo, Brazil Natural Science Foundation of China41171214