岩溶表层带水生动物微分布规律及水文环境影响--以Velika Pasica溶洞为例

Micro-distribution of epikarstic aquifer fauna and its hydrological interpretation:A case study of Velika Pasica Cave in Slovenia

文章以斯洛文尼亚Velika Pasica溶洞为例,对洞内4个常流型滴点进行了近7年(2006-2013年)的监测,包括各滴点的水文特征,岩溶表层带水生甲壳类的微分布特征等;利用多元分析方法中的聚类分析和典范对应分析(CCA)讨论了岩溶表层带甲壳类微分布与水文因子之间的关系。研究发现:(1)4个滴点的水文变化特征表现出很大的差异性;通过聚类分析,12种甲壳类分为4个类型,与4个滴点有很好的对应关系;(2)排序分析发现,主要水文影响因子为最大排泄量(Max)、总排泄量(Q)和滴水温度(Temp),其中前两者与第一轴保持良好的正相关,Temp与第一轴负相关;(3)物种的分类与排序分析结果很吻合,在主要的7种甲壳类中,Pseudocandona albicans和Speocyclops infernus主要集中分布在VP1处,与Q成很好的正相关;VP2处的主要物种是Morariopsis dumonti和Bryocamptus typhlops,与Max和Q成负相关;Byocamptus pyrenaicus和Elaphoidella millennii主要分布在VP3处,趋于较适中的水文环境;Moraria varica为VP4特有的物种,与滴水温度表现出较强的相关性;(4)CCA排序轴的特征根值之和占了总特征根的33.8%,可解释一部分重要的物种分布特征,未能被解释的部分可能归结于未被选取的因子如水化学或者随机过程等。因此,不同环境因子影响着各滴点处特定的物种微分布,同时不同的物种分布具有对相应环境特征的潜在的指示作用。

Intensive and long-term monitoring on hydrological parameters has been performed at four permanent dripping sites（VP1-VP4）in the Velika Pasica Cave（Slovenia）from 2006 to 2013,in combination with aquatic fauna sampling.Multivariate analytical methods,such as cluster analysis and CCA method,were applied to elucidate the hydrological conditions associated with the spatial distribution of aquatic fauna within the cave and species composition at each dripping site.（1）It was found that hydrological characteristics of these four drip are distinct from each other.（2）By using cluster analysis,12 species are divided into 4groups,which correspond to four drips quite well.By employing CCA,the main hydrological parameters are Max and Q,which positively correlate with the first canonical axis and the drip water temperature（temp）which is negatively correlated with the first canonical axis.（3）Seven major species show different affinities to environmental parameters：abundance of Pseudocandonaalbicansand Speocyclops infernus,concentrating in VP1 samples which are positively correlated with the volume of discharge（Q）,while abundance of Morariopsis dumonti and Bryocamptus typhlops,dominant at VP2,are negatively correlated with high discharges（Max）;Byocamptus pyrenaicus and Elaphoidella millennii,dominant at VP3,with preferred moderate hydrological conditions,while Moraria varica,dominant at VP4,is positively correlated with drip water temperature.（4）The sum of eigen value by CCA only accounts for 33.8% of total eigen value,which could explain partial of the fauna distribution,but the parts of which cannot be explained due to the unexpected factors,e.g.hydrochemistry,or some stochastic processes.It implies that specific micro-distributions of species among the drips are related to specific environmental parameters.