Floristic diversity surveys of 3 fences and 3 open vernal pools, from the Merced Vernal Pool and Grassland Reserve, 2022

This data was collected as a part of a project to determine grazing effects on vernal pool floristic diversity. The data is reported as cover classes (1: 0-1%, 2: 1-5%, 3: 5-25%, 4: 25-50%, 5: 50-75%, 75-95%, 7: >95% - following Marty et al., 2005). Each measurement was taken in a quadrant (0.5m^2) subdivided into 50 squares. Presence was counted and multiplied by 2 to estimate cover class. For analysis cover classes were converted to midpoints of ranges. Of the vernal pools studied 3 of them had been fenced off for 2.5 years (3 wet seasons) and the other 3 were otherwise undisturbed natural vernal pools. The fenced pools were pools 23, 26, and 27. Open pools were 24, 25, and 28. For context residual dry matter (RDM) measurements showed that the fenced pools had a plant biomass presence of about 2,721 lbs/acre and the unenclosed pools has a plant biomass presence of about 1,869 lbs/acre (which is above a target of 800 lbs/acre suggesting the parcel was perhaps already under grazed) which may be relevant to consider with this data. Measurements for data reported here were collected during 7 visits to the Merced Vernal Pool and Grassland Reserve (MVPGR) between March 23rd and April 10th of Spring 2022. Sampling started just after the height of peak bloom as the bloom season of 2022 came early due to low rainfall in the wet season. The GPS locations of the pools are as follows: (Pool number, Easting, Northing) (23, 733127, 4139785), (24, 733160, 4139866), (25, 733117, 4139911), (26, 733220, 4140510), (27, 733247, 4140619), (28, 733205, 4140642) The sample id breaks down as follows: (Pool number - pool/edge/upland, sample number - year)

本数据集为探究放牧对春季池沼植物区系多样性影响的项目所采集的数据。数据以覆盖度等级形式报告，分级标准遵循Marty等人2005年的研究：1级：0-1%，2级：1-5%，3级：5-25%，4级：25-50%，5级：50%-75%，75%-95%，7级：>95%。每个样方（面积0.5平方米）被划分为50个小方格，通过统计物种出现的方格数量并乘以2，以此估算覆盖度等级。后续分析时，将覆盖度等级转换为对应区间的中点值。本次研究共涉及6处春季池沼，其中3处已被围封2.5年（历经3个湿季），剩余3处为未受干扰的天然春季池沼；围封池沼编号为23、26、27，开放未围封池沼编号为24、25、28。相关残留干物质（residual dry matter, RDM）测量结果显示：围封池沼的植物生物量约为2721磅/英亩，未围封池沼的植物生物量约为1869磅/英亩——该值高于800磅/英亩的目标阈值，表明该地块可能此前存在放牧不足的情况，该背景信息可供本数据集分析时参考。本数据集的所有测量工作，于2022年春季3月23日至4月10日期间，在默塞德春季池沼与草原保护区（Merced Vernal Pool and Grassland Reserve, MVPGR）共开展7次野外采样。由于2022年湿季降雨量偏少，花期提前，因此采样工作于盛花期结束后启动。各池沼的GPS坐标如下（池沼编号，东向坐标，北向坐标）：(23, 733127, 4139785)、(24, 733160, 4139866)、(25, 733117, 4139911)、(26, 733220, 4140510)、(27, 733247, 4140619)、(28, 733205, 4140642)。样本ID的命名规则如下：（池沼编号-池沼/边缘/高地，样本编号-年份）