Studies On Characteristics Of The Macroalgae Community In Niangziguan Spring, North China

Niangziguan Spring Area is the largest karstic spring in north China.Its distribution across the Haihe River and Yellow River,the major tributaries are Taohe River,Wenhe River,Songxihe River and Qingzhanghe River.It locates at eastern Shanxi Province,36°55′- 36°15′N,112°20′-113°55′E, closes to Niangziguan Town,at the convergence of Taohe River and Wenhe River.The whole area is 7436km².The spring group mainly distributes from Chengjia Village to Weizeguan,about 7km long,and the exposed elevation is 360-392m.The catchment area of karst groundwater in Niangziguan Spring is 7436 km².The annual average discharge is 10.6m³Â·s(-1).Temperate continental monsoon climate is the location feature of Niangziguan Spring,and four seasons are distinguishable there.The annual average rainfall is 538-578mm. The annual temperature is 8.6℃-10.7℃.The chemical type of the spring is SO₄·HCO₃-Ca·Mg or SO₄·HCO₃-Ca.It contains total dissolved solids of 600-700 mg·L^-1,total hardness of 450-480 mg·L^-1,with the stable average temperature 19℃.From Apr.2002 to Jan.2007,11 times investigations were undertaken, summing more than 300 specimens.In this research,116 species(including varieties) of stream macroalgae had been identified,comprising 6 divisions, 9 classes,16 orders,23 families and 39 genera.Chlorophyta was the most diversified division.Cyanophyta ranked as second.There were 11 types of macroalgal communities in Niangziguan Spring, namely Comm.Cladophora+Bangia,Comm.Chara,Comm.Cladophora+ Compsopogon,Comm.Vaucheria,Comm.Spirogyra+ Microspora and Comm.Oscillatoria,Comm.Stigeoclonium +Cloniophora,Comm. Audouinella,Comm.Phormidium + Lyngbya,Comm.Cladophora,Comm. Batrachospermum.The result of planar distribution of macroalgae in Niangziguan Spring showed that the Wulong Spring had the most species,with 60 species. Pingyan was ranked as second,with 51 species.The third was Gun Spring ranked(49 species).Weizeguan Spring ranked fourth(30 species),Podi Spring ranked fifth(28 species),Chengxi Spring ranked sixth(25 species), the last one,Shuiliandong Spring had 21 species.The distribution of various kinds of macroalgae in the sampling sites showed that Chlorophyta had the largest number.Cyanophyta and Bacillariophyta distributed evenly and similarly.Charophyta and Rhodophyta had less species.According to Sorensen-similar index,it was found that Niangziguan Spring and Xin'an Spring had a higher similarity index(0.712),which was greatly different with macroalgae in other countries in where the similarity index was generally low(between 0.028-0.169).Spring macroalgae had obvious geographical distribution and reproductive isolation.It was investigated the stream macroalgae and water analysis on 7 sampling sites every two months,from Mar.2006 to Jan.2007,including the composition,biodiversity and environmental factors.The results of biodiversity analysis indicated that there were the highest of diversity index and evenness index of in most months,Podi Spring and Chengxi Spring were at the lowest level.However,the dominance index was just the opposite in most months.Wulong Spring was the lowest of the dominance index,Podi Spring and Chengxi Spring were at the highest level. The results of annual changing showed that it had the positive correlation between diversity index and evenness index.Correspondingly,diversity index and evenness index had the negative correlation.The three biodiversity indicators could well indicate the algae diversity of Niangziguan Spring.In this research,the Principle component analysis(PCA) was applied to investigate the influence of environmental factors on distribution of macralgae.The results showed that the key factor was current velocity, affecting the distribution of the macralgae.Next was the width and depth of the water and other chemical factors.From the results of CCA showed that the current velocity was the key factor on the community.The current velocity was positively correlated with Comm.Cladophora + Bangia,Comm.Vaucheria,Comm.Audouinella, Comm.Oscillatoria,Comm.Stigeoclonium + Cloniophora,Comm. Phormidium+Lyngbya,Comm.Spirogyra + Microspora,but negatively with Comm.Batrachospermum and Comm.Chara.Temperature was also a dominate factor,which was positively correlated with Comm.Stigeoclonium + Cloniophora,Comm.Oscillatoria,Comm.Phormidium+Lyngbya,Comm. Spirogyra+Microspora,and negatively correlated with other communities. Especially Conductance was only negatively correlated with Comm. Vaucheria.It had positive correlations with Comm.Cladophora+ Compsopogon,Comm.Audouinella,Comm.Phormidium+ Lyngbya.At the same time,there were some correlations between the chemical factors and the communities,which affected greatly on Comm. Stigeoclonium+Cloniophora and Comm.Vaucheria.Among them,pH is negatively correlatied with Comm.Oscillatoria and Comm. Batrachospermum.It showed that Comm.Oscillatoria and Comm. Stigeoclonium+Cloniophora could grow well in spring water with high concerntration of N and P,whereas Comm.Batrachospermum was opposite. Accordingly,there were different environment factors effect on the distribution of macroalgae community on every sampling site.Moreover,it was similar to the environment factors on macroalgae community at the same site.There were 148 species of epiphytic algae in Niangziguan Spring, comprising 4 divisions,6 classes,12 orders,19 families and 36 genera. Among them,Bacillariophyta was preponderant with 118 species,about 79.7%.The result of planar distribution of Epiphytic algae showed that there were the most species in Pingyang Lake with 89,while the least was in Podi Spring with 22 species.There were seasonal dynamics in the species number of Epiphytic algae.It most occured in spring,next in autumn,the winter were least.The findings also showed that it was similar with macroalgae in seasonal changes,both positive correlation(r=0.963,p＜0.05).Finally,the survival crises of stream macroalgae in Niangziguan Spring were analyzed and in view of this situation,some conservation strategies were suggested in this paper.