DOI: 10.5061/dryad.wwpzgmsqv
title: Climate change causes declines and greater extremes in wetland inundation in a region important for wetland birds

description: Wetland ecosystems are vital for maintaining global biodiversity, as they
 provide important stopover sites for many species of migrating
 wetland-associated birds. However, because weather determines their
 hydrologic cycles, wetlands are highly vulnerable to the effects of
 climate change. Although changes in temperature and precipitation
 resulting from climate change are expected to reduce inundation of
 wetlands, few efforts have been made to quantify how these changes will
 influence availability of stopover sites for migratory wetland birds.
 Additionally, few studies have evaluated how climate change will influence
 inter-annual variability or the frequency of extremes in wetland
 availability. For spring and fall bird migration in 7 ecoregions in the
 south-central Great Plains of North America, we developed predictive
 models associating abundance of inundated wetlands with a suite of weather
 and landcover variables. We then used these models to generate predictions
 of wetland inundation at the end of the century (2069–2099) under future
 climate change scenarios. Climate models predicted the average number of
 inundated wetlands will likely decline during both spring and fall
 migration periods, with declines being greatest in the eastern ecoregions
 of the Great Plains. However, the magnitude of predicted declines varied
 considerably across climate models and ecoregions, with uncertainty among
 climate models being greatest in the High Plains ecoregion. Most
 ecoregions also were predicted to experience more-frequent extremely dry
 years (i.e., years with extremely low wetland abundances), but the
 projected change in inter-annual variability of wetland inundation was
 relatively small and varied across ecoregions and seasons. Because the
 south-central Great Plains represents an important link along the
 migratory routes of many wetland-dependent avian species, future declines
 in wetland inundation and more frequent periods of only a few wetlands
 being inundated. resulting in an uncertain future for migratory birds as
 they experience reduced availability of wetland stopover habitat across
 their migration pathways. 
description: We estimated the number of inundated wetlands in the southern
 Great Plains for each year from 1991–2020 using the USGS Dynamic Surface
 Water Extent Product. The DWSE is a free remote sensing data product that
 is available online through the USGS. Number of inundated wetlands was
 estimated for two time periods relevant to migratory birds in each year
 the spring migration as 1 March–31 May and fall migration as 1
 September–31 November. Wetlands were determined to be inundated at in a
 given season if they were observed to have water in at least 2
 Landsat/DSWE images.  Data was summarised into 10 x
 10km grid covering the entire southern great plains in addition to the
 number of inundated wetlands per grid cell in each year we also recorded a
 number of variables related to weather and land cover. The weather
 variables include: total precipitation (mm), mean daily average
 temperature (°C), precipitation balance (measured over 3 time scales: 3
 months, 6 months and 12 months prior to migration), and mean daily maximum
 temperature. Land cover included % cover of crops, grasslands, trees, and
 development as well as terrain roughness index and the number of wetland
 basins. A full description of how each of these variables was derived can
 be found in the full text of the associated manuscript.
description: # Climate change causes declines and greater extremes in wetland
 inundation in a region important for wetland birds.
 [https://doi.org/10.5061/dryad.wwpzgmsqv](https://doi.org/10.5061/dryad.wwpzgmsqv) We estimated the number of inundated wetlands in the southern great plains for each year from 1991-2020 using the USGS Dynamic Surface Water Extent Product. The DWSE is a free remote sensing data product that is available online through the USGS. Number of inundated wetlands we estimated for two time periods relevent to migratory birds in each year the spring migration as 1 March - 31 May and fall migration as 1 September - 31 November. Wetlanbds were determined to be inundated at in a given season if they were observed to have water in at least 2 landsat/dswe images.  Data was summarised into 10 x 10km grid covering the entire southern great plains in addition to the number of inundated wetlands per grid cell in each year we also recorded a number of variables related to weather and land cover. The weather variables include: total precipitation (mm), mean daily average temperature (<sup>o</sup>C), precipitation balence (measured over 3 time scales 3-months, 6 months and 12 months prior to migration), and mean daily maximum temperature. Land cover included % cover of crops, grasslands, trees, and development as well as Terrain roughness index and the number of wetland basins. A full description of how each of these variables were derived can be found in the full text of the associated manuscript. ## Description of the data and file structure Included are two Excel files, one for each season with all variables needed to recreate our random forest data-analysis. Each row is associated with a 10x10 km grid cell/ year combination (each cell should occur 30 times, once for each year). Cell ID is recorded as FID\_sample in the spreadsheet and the year is recorded in the year or y1 columns. The Latidude and Longitude of the centroid of each grid cell is recorded in the Lat, Long columns respectively. The number of inundated wetlands in each cell per year is recorded in the wet.num column, rows with NA indicate rows cells where no wetlands occur. Seasonal precipitation, mean temperature and maximum temperature and represented by the variables season\*.ppt, season\*.tmean, season.tmax where season\* corresponds to fall, spring, summer, or winter in the excel sheet. precipitation balance is represented by bal3 (3-month precipitation balance), bal6 (6-month precipitation balance), and bal12 (12-month precipitation balance). Precipitation is in millimeters, temperature is in degrees Celsius and precipitation balance (bal3, bal6, bal12) is a unitless metric that represents the unstandardized difference between precipitation total and evapotranspiration potential. The TRI represents terrain roughness index which was calculated as the average difference between neighboring pixels in a 30 m resolution Digital Elevation Map of the southern Great Plains. The crop10, dev, tree, grass represent the percent cover of croplands, developed areas, forests, and grasslands respectively. All percent cover variables were derived from the USDA NASS cropland dataset. All analyses were conducted at the ecoregion level, with each grid cell's ecoregion being denoted in the ecoregion column. The Area column denotes the area of each grid cell in kilometers squared. ## Sharing/Access information This is a section for linking to other ways to access the data, and for linking to sources the data is derived from, if any. DSWE data can be downloaded from https://earthexplorer.usgs.gov/ Future climate data is not included here due to file size, but can be accessed at https://gdo-dcp.ucllnl.org/downscaled\_cmip\_projections/dcpInterface.html ## Code/Software