Factors influencing the coastal plant species diversity in the Mikawa Bay, Aichi Prefecture, Japan.

Abstract

In this study, we investigated the relationship between species richness of coastal plants and the landscape ecological factors such as area, isolation distance from the large seed source, and patch width in the urban or suburban 50 sandy coast patches in the Mikawa Bay (Aichi Prefecture, Japan). We performed stepwise multiple regression analysis to examine the factor s influencing the coastal plant species diversity, which revealed that the number of the coastal plant species exhibited a significantly positive correlation with the logarithm of area of the sandy coast patches, whereas it exhibited a negative correlation with the isolation distance from the large coastal dune Enshu-nada. The factors influencing the occurrence probability of each coastal plant species was examined using logistic regression analysis. This analysis revealed that the most effective explanatory variable was the patch area, and the isolation distance from the large sand dune ranked the second most effective explanatory variable. Furthermore, we verified the accuracy of the obtained 10 logit models of coastal dune plants using the receiver operating characteristic (ROC) curve and area under the curve (AUC). The 8 models such as Cirsium maritimum, Ischaemum anthephoroides, and Zoysia macrostachya evaluated had sufficient predictive accuracy. This study revealed that these species were affected by the degree of isolation, area, and or patch width.