求翻译：从田间持水能力的空间变化看,随着土壤深度的增加,各森林土壤田间持水量出现减小趋势，其变化范围在54.12～493.66之间，腐殖质层变化范围在187.49～493.66 cm/s之间，以柴桦是什么意思？

From field holding water ability of space changes see, as soil depth of increased, all forest soil field holding water appears reduces trend, its changes range in 54.12~493.66 Zhijian, humus layer changes range in 187.49~493.66 cm/s Zhijian, to fruticosa Pall-gmelini larch forest maximum, Creek next-gmelini larch forest minimum; Dian product layer changes range in 54.12~252.11 cm/s Zhijian, to really China-gmelini larch forest maximum, Ledum palustre-gmelini larch forest minimum. But this surface storage of water, evaporation, storage time is short, moisture, and from that point of consideration, should strengthen the grass layer, under forest litter layers of protection, improving water use efficiency.