One of the most controversial issues in ecology is the degree to which communities are assembled by stochasticity or a set of deterministic processes. However, the processes governing population dynamics may vary greatly among species
Researchers from University of Maryland and Xishuangbanna Tropical Botanical Garden (XTBG) proposed a core-transient framework for trait based community studies where a core group of species has a strong link to the local environment while transient species have weaker responses to the environment.
The researchers conducted the study in a tropical rainforest t at Xishuangbanna, Yunnan province in China (101°340′ E, 21°360′ N). They analyzed 1506 seedlings distributed in 214 plots of 1 × 1 m2 established in a regular grid across 2-ha.
The researchers examined the role that local environmental conditions and individual traits play in influencing tree seedling growth performance for communities in Xishuangbanna forest.
They found that core, generally common, species tend to exhibit clearer responses to local resource availability variation and their traits play an important role in mediating the resource acquisition promoting seedling growth. On the other hand, transient, usually rare, species are more limited in their responses.
Similarly, they found that traits ( leaf area, specific leaf area, leaf thickness, leaf mass fraction, stem mass fraction, root mass fraction, stem specific length and leaf area ratio) linked to resource acquisition were related to seedling growth for common species, but the relationship was frequently weak for rare species.
Light and soil nutrients were linked to the traits and growth performance. Together with soil nutrients, light showed a significant positive effect on seedling performance.
The researchers, therefore, proposed that the core species have a strong deterministic relationship with the local environment. The arrival of new seeds into the population is largely driven by the reproductive success of local adult individuals, which ultimately results in large and persistent populations.
The research results highlight the importance of moving trait-based community ecology beyond the consideration of a community as a unit where species are equally influenced by stochastic or deterministic factors.
The study entitled “A core-transient framework for trait-based community ecology: an example from a tropical tree seedling community” has been published online in Ecology Letters.
Contact
CAO Min Ph.D Principal Investigator
Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan 666303, China
Tel: 86-871-65160998
E-mail: caom@xtbg.ac.cn
Xishuangbanna tropical forest (Image by MO Xiaoxue)
