A negative polynomial model is used to depict the positive correlation distributed samples of multiple species.

Species distribution in nature is often non-random and often presents a state of aggregation.
traditional studies using negative two-item models can well depict the cluster distribution state that a single species often presents, but the distributed samples of multiple species in ecological communities are not yet known.
, Chen Youhua, a researcher at the Chengdu Institute of Biological Sciences of the Chinese Academy of Sciences, and Shen Zongxuan, a professor at the Department of Applied Mathematics and Statistics at ZTE University in Taiwan, Richard Condit, a renowned ecologist at the Smith Institute in the United States, and Stephen Hubbell, the father of the theory of neutral community ecology, worked together to propose the use of negative polynomial models to depict the positive correlation of multiple species.
negative polynomial model has a good statistical nature, and shape parameters (also known as aggregation parameters in negative binary models) can satisfy the principle of sampling scale invariance.
the model has better distribution and multi-degree data fit on regional and local scales for tree species in permanent forest-like fields, and many times it is better than the fitting effect of independent negative dual model.
these results show that the distribution of multispecies in the community is not necessarily fully presented with a high-concentration distribution state, there may be a certain positive correlation of the distributed sample or the cluster and random mix of distributed samples.
this work and put forward a new theoretical framework, trying to distinguish the distributed samples of single species and multi-species in ecological communities, and to explore the scale of the parameters of the model.
's findings are published online in the International Journal of Ecology and the American Society of Ecology by Community-level species' correlated distribution can be scale-independent and related to the international science and ness of the journal Ecology.
the research results were completed with the support of the Chinese Academy of Sciences' strategic pilot science and technology special "Large-scale Regional Biodiversity Patterns and Life Strategies" (XDB3100000) and the "100-person Program" C-type Young Talent Project (Y8C3041100) of the Chinese Academy of Sciences.
Source: Chengdu Institute of Biology.