Every agricultural system produces a surplus of waste and hard-to-use biomass that is best kept in the food chain by feeding it to livestock .
每种农业系统都会制造出多余的难以被利用的生物量,而这些最好是通过饲养牲畜而保持在食物链中。
One similarity between the two types of succession is that they both lead to an increase in the biomass of the area .
两种演替形式的相似之处在于:演替结果必然导致该地区生物量的增加。
That matters because theory suggests that the maximum sustainable yield that can be cropped from a fishery comes when the biomass of a target species is about 50 % of its original levels .