Predicting Dynamics of the Potential Breeding Habitat of Larus saundersi by MaxEnt Model under Changing Land-Use Conditions in Wetland Nature Reserve of Liaohe Estuary, China

Yu Chang,Jiujun Lv,Yuanman Hu,Chang Chang,Yuxiang Li,Miao Liu

doi:10.3390/rs14030552

Abstract

Identifying waterfowl habitat suitability under changing environments, especially land-use change, is crucial to make waterfowl habitat conservation planning. We took Wetland Nature Reserve of Liaohe Estuary, the largest breeding area of Saunders’s Gulls (Larus saundersi) in the world, as our study area, generated land-use-type maps through interpretation of satellite images from four different years (1988, 2000, 2009, 2017), and predicted the potential breeding habitat of Saunders’s Gulls by MaxEnt model based on the land-use map, along with other environmental variables (NDVI, distance to roads and artificial facilities, distance to rivers and water bodies, DEM and distance to shoreline) for the four years, respectively. The models were evaluated using the area under the curve (AUC). We analyzed the changes of the breeding habitat from 1988 to 2017 and utilized RDA to explore the relationships among the changes of suitable habitat of Larus saundersi and the dynamics of land uses. Our results showed that the most suitable habitat decreased by 1286.46 ha during 1988-2009 and increased by 363.51 ha from 2009 to 2017. The suitable habitat decreased by 582.48 ha from 1988 to 2009 and then increased to 1848.96 ha in 2017, while the unsuitable habitat increased by 2793.87 ha during 1988–2009 and then decreased by 178.83 ha from 2009 to 2017. We also found that land use, distance to the coastline, distance to artificial facilities, distance to rivers, distance to roads, and NDVI had certain degrees of impact on the Larus saundersi distribution. The contribution of land use ranged from 16.4% to 40.3%, distance to coastline from 34.7% to 48.0%, distance to artificial facilities from 5.9% to 11.1%, distance to rivers from 5.5% to 11.0%, distance to roads from 3.9% to 12.5%, and NDVI from 0.3% to 6.3%. The change in suitable habitat of Larus saundersi has a positive relationship with the change of seepweed marsh. Human-induced changes in seepweed marsh and coastline position are the main factors influencing the potential breeding habitat of Saunders’s Gulls. We suggest strict conservation of seepweed marsh and implementation of habitat management practices to better protect Saunders’ Gull’s breeding habitat.

Highlights

We first generated land-use-type maps of WNRLE for four different years (1988, 2000, 2009, 2017) through interpretation of satellite images to explore how land uses change during the three decades; we predicted the potential breeding habitat of Saunders’s gulls in each of the four years using the MaxEnt model based on the land-use map, along with other environmental variables, and analyzed the changes in the potential breeding habitat of Saunders’s gulls from 1988 to 2017; we proposed some suggestions for Saunders’s gull conservation
We found that land use, distance to the coastline, distance to artificial facilities, distance to rivers, distance to roads, and the normalized difference vegetation index (NDVI) had certain degrees of impact on the Larus saundersi distribution
We chose land use/cover as an indicator for food abundance, the NDVI for vegetation cover, the digital elevation model (DEM) and distance to the coastline as indirect indicators for food abundance because they influence the distribution of vegetation, distance to rivers and water bodies for water availability, and distance to roads and constructed facilities for human disturbance intensity

Summary

Introduction

Wetlands are large carbon sinks [1,2,3] that can be used for climate mitigation, maintaining high biodiversity [4], and they are crucial habitats for various waterbird species [5,6]. To meet land requirements for social and economic development, wetland loss and degradation are common phenomena in coastal regions worldwide. Research shows that at least 33% of global wetlands have been lost [7]. The loss of these wetlands has seriously threatened the habitat of waterfowl [8] and biodiversity [9]. The loss of these wetlands has seriously threatened the habitat of waterfowl [8] and biodiversity [9]. 4.0/).

Methods

Discussion

Conclusion