Water chemistry of playa wetlands in the Southern High Plains region of Texas from May - August 2019

Playa wetlands are the primary hydrological features in the Southern High Plains region of Texas. Texas playas are located predominantly on private land and gaining access for aquatic habitat surveys can be challenging. The associated data are provided to increase publicly-available water chemistry measurements from regional playa wetlands in rural environs. 

Methods
Playas are located in Deaf Smith (n = 5), Castro (n = 1), Floyd (n = 6), Hale County (n = 4), Texas, USA. To protect landowner privacy, geographic coordinates are not provided. From May - August 2019, all playa basins were dominated by cropland buffers (≤1 km) and located ≥2 km from asphalt-paved roadways. All playas were sampled once from May - June, and playas that were still inundated in July - August were sampled a second time. Sampling occurred between 1100–1700 hrs. An AMTAST Portable Dissolved Oxygen and Temperature Meter (DO Range: 0–20.0 mg/L; AMTAST USA, Inc.; Lakeland, FL, USA) was used to measure dissolved oxygen (DO), an ELITEPHKIT Waterproof pH Tester (Thermo Fisher; Carlsbad, CA, USA) was used to measure pH and water temperature. Surface water samples were also collected in a 50-mL polypropylene centrifuge tube and stored on ice for transport to Texas Tech University (Lubbock, Texas, USA), where a HACH DR3900 Laboratory VIS spectrophotometer was used to measure nitrate and ammonia concentrations.

普拉亚湿地（Playa wetlands）是美国德克萨斯州南部高平原地区的核心水文特征。德克萨斯州的普拉亚湿地大多分布于私人土地之上，因此开展水生栖息地调查所需的场地准入工作颇具挑战。本数据集提供相关实测数据，旨在扩充乡村区域内该地区普拉亚湿地的公开水质化学测量数据集。

研究方法
本次研究涉及的普拉亚湿地分布于美国德克萨斯州的迪夫史密斯县（n=5）、卡斯特罗县（n=1）、弗洛伊德县（n=6）以及黑尔县（n=4）。为保护土地所有者隐私，本次研究未公开各湿地的地理坐标信息。
2019年5月至8月期间，所有普拉亚湿地盆地周边均以≤1km的农田缓冲带为主，且距离沥青铺装道路≥2km。所有湿地均于5月至6月完成一次采样；若湿地在7月至8月仍处于积水状态，则进行二次采样。采样时间均设置在每日11:00至17:00之间。
使用AMTAST便携式溶解氧与温度测试仪（测量范围：0–20.0 mg/L；AMTAST美国公司，美国佛罗里达州莱克兰市）测定溶解氧（DO）；使用ELITEPHKIT防水pH测试仪（赛默飞世尔科技，美国加利福尼亚州卡尔斯巴德市）测定pH值与水温。同时采用50mL聚丙烯离心管采集表层水样，置于冰上保存并转运至美国德克萨斯理工大学（美国德克萨斯州拉伯克市），采用HACH DR3900实验室可见光分光光度计测定水样中的硝酸盐与氨氮浓度。