Plant Water Potentials and Plant Physiology at the Sevilleta National Wildlife Refuge, New Mexico (1989-1992)

Physiological status of plants is monitored in conjunction with the sampling schedule outlined in Sevilleta Plant Demography. Several perennial life forms, including tree (Juniperus and Pinus), shrub (Larrea) and grass (Oryzopsis and Sporobolus), are being monitored at 1-3 of four sites which differ in elevation and topography as well as edaphic and annual precipitation characteristics. For the 1990 field season we are adding a spring annual, Lesquerella to our sampling efforts at these same sites. Currently, water status (xylem potentials, bars) is monitored twice a year, in spring (after the 'dry' season) and fall (after the 'wet' season). Three replicate measurements are made on each of 10-20 individuals per species per site. Three measurements are made at pre-dawn and midday to determine the diurnal range of values for each plant. For the 1990 field season, we will also be measuring peak photosynthetic rates for selected individuals by gas exchange measurements and porometry. Together with demographic data, this data set permits assessment of the physiological bases of plant growth and reproduction in response to short- and long-term changes in abiotic and biotic aspects of the environment.本数据集结合《塞维列塔植物种群统计学》（Sevilleta Plant Demography）所拟定的采样方案，对植物生理状态开展监测。本研究在4个具备不同海拔、地形、土壤特性及年降水特征的样地中选取1至3个样点，覆盖多种多年生植物生活型，包括乔木（桧属Juniperus、松属Pinus）、灌木（拉瑞阿属Larrea）以及草本（稻穗草属Oryzopsis、鼠尾粟属Sporobolus）。1990年野外季期间，我们新增春季一年生植物团扇荠属Lesquerella，将其纳入上述样地的采样工作中。 目前，我们每年开展两次植物水分状态监测，监测指标为木质部水势（单位：巴（bars）），分别于春季（旱季结束后）与秋季（湿季结束后）进行。每个样地中，针对每一物种的10至20株个体，各开展三次重复测量；并分别于黎明前与正午各完成三次测量，以获取单株植物的日变化数值范围。1990年野外季中，我们还将通过气体交换测定法与气孔计法，针对选定个体测量其光合速率峰值。 结合种群统计数据，本数据集可用于评估植物生长与繁殖的生理基础，及其对环境中非生物与生物因子短期及长期变化的响应。