Vol. 60, 2021
Quantifying the Effect of Land-cover Change on the Endangered Farmland Green Treefrog (Zhangixalus arvalis) in an Agricultural Landscape: Implications for ConservationSin Chen1, Meng-Hsien Chuang2, Hau-Jie Shiu3, and Jian-Nan Liu1,*
of Forestry and Natural Resources, National Chiayi University, Chiayi
600355, Taiwan. *Correspondence: E-mail: email@example.com (Liu).
Tel: +88652717485. Fax: +88652717467.
Received 3 February 2021 / Accepted 16
Habitat loss and fragmentation have
a significant negative effect on amphibian species, particularly those
with specialized habitat requirements. The endangered farmland green
treefrog (Zhangixalus arvalis) primarily inhabits woodlands of
agricultural landscapes in central Taiwan. Recently, due to increased
demands for pineapple products, many woodlands, particularly bamboo
plantations, were converted to pineapple fields. This study aimed to
quantify the effect of habitat loss and fragmentation on Z. arvalis due
to change of land cover in an agricultural landscape. The study area
contained 34,243 50 m × 50 m grids. In 2006 and 2014–2015, we used
acoustic surveys to survey the occurrence of Z. arvalis in each grid.
We obtained satellite images of the study area for 2006 and 2014, and
we assigned the land-cover type of each grid to one of the following
six types: woodland, brushland, cropland, bareland, manmade structures
and water body. We examined whether Z. arvalis preferred a certain
land-cover type by comparing the proportion of cover types available
and the proportion of cover types used by the frogs. Furthermore, we
used occurrence records for 2006 and 2014–2015 and applied the Maximum
Entropy Model to predict suitable habitat for the respective years. We
mapped the loss of suitable habitat and used six indices to quantify
habitat fragmentation within the 8 years. We also tested the prediction
that the occupancy rate of Z. arvalis in different-sized habitat
patches was a function of patch size. Z. arvalis exhibited a strong
preference for woodland, but avoided cropland and manmade structures.
From 2006 to 2014–2015, the suitable habitat decreased 4.1%, and all
six indices showed an increase in habitat fragmentation. The occupancy
rate of different-sized woodland patches was positively correlated with
patch size. Mapping suitable habitat and identifying the potential gaps
in functional habitat connectivity can be used to guide effective
measures for conservation of Z. arvalis.
Key words: Farmland, Habitat connectivity, Habitat specialist, Metapopulation, Species distribution model.
Citation: Chen S, Chuang MH, Shiu HJ, Liu
JN. 2021. Quantifying the effect of land-cover change on the endangered
Farmland Green Treefrog (Zhangixalus arvalis) in an agricultural
landscape: implications for conservation. Zool Stud 60:71.