种间关系是指生物群落中各个物种之间所形成相互关系。主要有食物的关系，即一种生物以另一种生物为食物的关系(包括寄生)，以及共栖、共生及对空间和其它生物生存条件等的竞争。

根据强弱双方和利害，可以将种间关系分为九种：

'0' 代表无影响， '-' 害，'+' 益

Biological interactions are the effects that the organisms in a community have on one another. In the natural world no organism exists in absolute isolation, and thus every organism must interact with the environment and other organisms. An organism's interactions with its environment are fundamental to the survival of that organism and the functioning of the ecosystem as a whole.