人类活动与互花米草扩张对滨海湿地生境质量演变的影响——以盐城国家级珍禽自然保护区核心区为例

Effects of Human Activities and the Expansion of Spartina Alterniflora on the Evolution of Habitat Quality of the Coastal Wetland:Taking the Core Area of Yancheng National Nature Reserve as An Example

生境质量是衡量盐城滨海湿地栖息地功能的重要指标,在人类活动和互花米草扩张的双重影响下,生境质量面临威胁。该研究以江苏盐城国家级珍禽自然保护区核心区为例,运用InVEST模型结合线性回归方程和冗余分析(RDA),辨析人类活动与互花米草扩张对生境质量的影响。结果表明:(1)人类活动强度指数(HAILS)呈现先上升后下降的趋势,最高值在2006年,为0.107 3;最低值在1992年,为0.007 8。互花米草面积(ASE)持续扩张,面积百分比从1.673%增加到24.930%。生境质量(HQ)总体上呈现下降趋势,1983~1992年,从0.863上升至0.875;至2014年,又下降至0.739 7;至2017年又上升至0.774 8。(2) HQ与HAILS、ASE呈显著负相关,相关系数分别为-0.940 2和-0.923 7;ASE对HQ的影响大于HAILS。(3) RDA排序能够反映HQ与HAILS、ASE的关系,10个时期的HQ被变量HAILS、ASE分在4个不同的象限。排序结果为:1983和1992年为第一类(第一象限),HAILS、ASE对生境影响都比较弱,二者的作用强度相当。1997、2000、2002、2006、2009年归为第二类(第三、四象限),HAILS对HQ的影响大于ASE的影响。2011、2014和2017年为第三类(第二象限),ASE对HQ的影响大于HAILS;阶段性特征明显。10个时期,HQ与HAILS相关性关系为,1983≈1992<1997≈2017 <2000≈2002≈2014 <2011 <2006 <2009;HQ与ASE相关性关系为,1997<1983≈1992<2000≈2002<2006<2017<2009<2011<2014。研究结果可为盐城滨海湿地世界自然遗产地的建设与管理提供参考。

Habitat quality is an important index to measure the habitat function of Yancheng coastal wetland.Under the dual influence of human activities and the expansion of Spartina alterniflora,the habitat quality is threatened. This study took the core area of Yancheng National Nature Reserve as an example,using the InVEST model combined with linear regression equation and the Redundancy Analysis (RDA) to analyze the impacts of human activities and the expansion of Spartina alterniflora on the habitat quality. The results showed that: (1)The human activity intensity index (HAILS) showed a trend of first rising and then declining,with the highest value of 0. 107 3 in 2006 and the lowest value of 0. 007 8 in 1992. The area of Spartina alterniflora (ASE)continued to expand,and area percentage increased from 1. 673% to 24. 930%. In general,habitat quality (HQ) showed a downward trend,from 0. 863 to 0. 875 in 1983-1992,from 0. 739 7 in 2014 to 0. 774 8 in 2017. (2) HQ had a significant negative correlation with HAILS and ASE,and the correlation coefficients were-0. 940 2 and-0. 923 7 respectively. ASE had more influence on HQ than HAILS. (3) RDA ranking can reflect the relationship between HQ,HAILS and ASE. HQ in 10 periods were divided into four quadrants by the variables of HAILS and ASE. The results of RDA ranking were divided into three categories: the first category was in 1983 and 1992 (the first quadrant). The impacts of HAILS and ASE on habitat were relatively weak,and the intensity of their effects was similar. The results in 1997,2000,2002,2006 and 2009 were classified as the second category (the third and fourth quadrants). The influence of HAILS on HQ was greater than that of ASE.The results in 2011,2014 and 2017 were the third category (the second quadrant). ASE has a greater impact on HQ than HAILS. The results of RDA ranking were with obvious stage characteristics. In 10 periods, the correlation between HQ and HAILS was 1983 ≈ 1992 < 1997 ≈ 2017 < 2000 ≈ 2002 ≈ 2014 < 2011 <2006 < 2009;the correlation between HQ and ASE was 1997 < 1983 ≈ 1992 < 2000 ≈ 2002 < 2006 < 2017< 2009 < 2011 < 2014. The results can provide reference for the construction and management of world natural heritage site of Yancheng costal wetland.