Fall 2003 crab population monitoring: mid-marsh and creekbank abundance based on crab hole counts at GCE marsh, monitoring sites 1-10

This data set is the Fall 2003 estimate of crab densities at the GCE-LTER marsh sites used for population monitoring. Crab abundance was determined by counting the number of crab holes within a 625 cm^2 quadrat and converting the counts to number per square meter. Counts were made in the mid-marsh and creekbank zones (n = 4 per zone) at all sites. This method does not differentiate which species made a particular hole and therefore only estimates total crab abundance. Plugged holes were excluded from the counts. Mean density across all sites and zones was 250 m^-2 (+/- 285 s.d.).

本数据集为2003年秋季针对用于种群监测的GCE-LTER沼泽监测点位的蟹类密度估算结果。蟹类丰度通过计数625平方厘米样方（quadrat）内的蟹洞数量，并将计数结果换算为每平方米的蟹类数量确定。所有监测点位均在沼泽中部带与溪岸带开展计数，每个区域设置4个重复样方（n=4）。该方法无法区分单个蟹洞所属的蟹类物种，因此仅能估算总蟹类丰度。已被封堵的蟹洞不计入本次计数范围。所有点位及区域的平均蟹类密度为250只/平方米（标准差±285）。