Soil microorganisms play an important part in maintaining soil quality. Soil microbial biomass represents the labile pool and can be used as a bio-indicator for evaluating soil quality.

土壤微生物是维持土壤质量的重要组分，土壤生物学指标能敏感地反映土壤质量的变化，土壤微生物量是土壤质量评价的一个重要的生物学指标。

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Dr Sneddon comments, "Sheep wool evidently has potential as a bio-indicator of naturally occurring heavy metal concentrations in upland areas, which have previously not been assessed in this way".

Sneddon博士评论认为：“羊毛显然可以作为丘陵地区重金属污染的生物指示剂，而以前这一特点一直都没有被注意到。”

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Frogs, which breathe and process toxins through their skin, are considered a promising area for pharmaceutical research and a bio-indicator that can tell scientists about what's going on in the environment.

NPR: Alarm Over Vanishing Frogs In The Caribbean