Abstract The term of ecological model refers to a wide variety of types of models which simulate various ecosystem phenomena at different scales. Those models could be classified into various types according to different criterion. The progresses of three main macro-scale models were summarized in this paper. l) Population dynamics models (PDMs) simulate the germination, growth and mortality of individual plants in an ecosystem, and also consider competition within species, and interaction between species. PDMs are pioneering in ecological modeling, which include individual-based models, micro-site-based competition models, matrix population models and spatially explicit population models. Those models focus on interactions between populations in an ecosystem, and ignore or maybe simplify the processes of soil-moisture-atmosphere transfer in the vertical connections. This type of model is mostly used to study the dynamic of populations. 2) Succession models (SMs) simulate the replacement of plant species (accompanying with animals) through the succession of ecosystems, including the transformation of vegetation types and the corresponding changes (influences) in biogeochemical cycling. The theoretical basis of SMs is population dynamics theory proposed by Clements, importance theory of species features in dynamic ecosystems by Gleason, ecosystem theory by Tansley, and relation theory between spatial pattern and internal dynamics within system by Watt. The models could be applied to the community responses to global climate changes. 3) Ecosystem models which take ecosystem as a functional body, include: a) Soil-vegetation-atmosphere transfer models (SVAT) that simulate land surface ecological processes, especially climatic studies. Those are BATS (biosphere-atmosphere transfer scheme), SiB (simple biosphere model), SiB2 and LEAF (land ecosystem atmosphere feedback model). SVATs simulate moisture-thermal processes of soil-plant-atmosphere continuum, based on the Monteith-Perman equation and the Darcy equation, and considering the effects of plant leaves on the selective absorption and reflection of radiations, the effects of canopies on transpiration, moisture-thermal translation and momentum exchange; b) Biogeochemistry models (BGC models) simulate the processes of photosynthesis, transpiration and decomposition and calculate the flux of the cycling of water, carbon, and nutrients on the interface of soil-vegetation-atmosphere in the ecosystems. The climate, soil condition, and vegetation types must be input as initialized variable. BGC models include FOREST-BGC, BIOME-BGC, CENTURY, TEM, DOLY and the integrated model group derived from them; 3) Biogeographic models (BGMs), which simulate the composition and distribution of vegetation on the bases of the eco-physiological adaptive of plants to the environment and the competitive capacity for resources. By using the concept of functional type, plants can be grouped into trees, shrubs and grasses or two photosynthesis types of C3 and C4. BGMs could be used to study organism distribution shift induced by climate change.
The trends of the macro-scale plant ecological models are: firstly, linking ecological models with other sciences, for example, introducing phenology into modeling, to seek its new development; secondly, linking models with modem non-linear theories for the reevaluation of the basic hypothesis for modeling; thirdly, linking models with modem science-technology such as 3S, IT and so on, for the stronger support from technologies, and finally, the concept of model development having been altering from individulism to holistism, which simulate a ecosystem as a whole functional unit.