An Expert-Based Assessment Model for Evaluating Habitat Suitability of Pond-Breeding Amphibians

Abstract

Farm ponds are important habitats for amphibians, birds, and other wildlife. In Taiwan, artificial ponds were originally created on farmlands for irrigation purposes and the needs of the domestic water supply. Although pond creation is a typical farming practice, it also provides habitats for pond-breeding amphibians. Thus, it is essential to understand the current status of habitats and their vulnerability regarding urgent conservation needs for target species. Günther's frog (Hylarana guentheri), a pond-breeding amphibian, has a high sensitivity towards surrounding environmental changes, and can be used as an indicator species to assess habitat suitability. The purpose of this study is to establish a systematic framework to assess the habitat suitability of pond-breeding amphibians by using Günther's frog as a pilot-study species. First, we collected frog survey data from Chiayi, Taiwan, from winter 2013 to spring 2015, and investigated the present status of the environmental conditions around the ponds. Next, expert questionnaires and the fuzzy Delphi method were applied to establish the hierarchical evaluation criteria regarding the habitat suitability assessment. Four indicators: the aquatic environments of farm ponds; the terrestrial environments around ponds; landscape connectivity; and the conservation perceptions of the residents, were determined as first-layer factors in the assessment criteria, while ten other indicators were defined as second-layer factors. Based on the established assessment criteria, we performed in situ habitat suitability evaluations on 69 selected sites and surveyed the perceptions of the residents using questionnaires. Results revealed that 19% of locations were rich in frog species with a high habitat suitability. However, 67% of locations showed signs of habitat degradation, which may imply a higher need in practicing habitat improvement or restoration. The Kappa value was 0.6061, which indicated a high reliability of the habitat suitability assessment model. In brief, the proposed method can be applied, not only to assess the sustainability of frog habitats and degradation risks, but also to determine which locations may require future attention regarding conservation implementation. Furthermore, findings in this study provide useful background knowledge to all associated stakeholders when designing and implementing plans of wildlife habitat management and restoration at farm ponds.

Identifying Farm Pond Habitat Suitability for the Common Moorhen (Gallinula chloropus): A Conservation-Perspective Approach

“…When the panel of experts formed a consensus and the indicators reached convergence, the triangular fuzzy number was greater than 0 [4,5]. When the experts' opinions were consistent, and the evaluation criteria achieved convergence in the fuzzy Delphi relationship, there was no standard threshold.…”

“…The terrain on the west side of Chiayi County is flat and serves as a crucial area for rice production. However, because uneven monthly rainfall and distinct dry and wet seasons are not conducive to rice cultivation, farm ponds are used as water storage facilities [1,2,5]. From 1995 to 2007, approximately 30% of farm ponds in Chiayi County disappeared (i.e., a decrease from 1535 to 978).…”

“…Originally, the Delphi method was developed as a systematic, interactive forecasting, and organized communication technique which relied on a group of experts [4,5]. Later, an improved and more elaborated version, the fuzzy Delphi method, was developed.…”

“…We introduced the systematic approach with six steps, proposed by Chou et al and Juang et al, to test experts' consensus [4,5]. An expert questionnaire was used to interview the experts.…”

“…By 1995, the number of farm ponds in Southwestern Taiwan had reached 10,518 [1,2]. However, as industrial and urban development in Taiwan has reduced the demand for agriculture, the importance of farm ponds for irrigation use has decreased drastically [3][4][5]. As a result, the common occurrence of domestic wastewater discharge and waste disposal into farm ponds, as well as the filling of farm ponds, has led to excessive algae growth, eutrophication of water quality, and reduction of aquatic animals and plants, resulting in damage to biological habitats [6].…”