青藏高原荒漠样点实测植物地上生物量和遥感净初级生产力数据集（2000-2020）

在青海和西藏的荒漠带实地调查了52个样点，于2019年和2020年7-8月植被生长最大时期对植被地上生物量进行实地采样。同时，利用手持 GPS设备，记录了实验位点的经度、纬度和海拔等信息。样方的野外设置方法为：选取一块植被均匀的地段，当植被相对茂盛时样地设置为10米x10米的正方形样地，当植被相对稀疏时样地设置为30米x30米的正方形样地或者30米x90米的长方形样地；在设置好的样地中随机投掷3-5个小样方框（1米x1米），采用样方收割法收集植物样品：在1平方米的样方面积内，登记植物的物种名目，每个物种的株数等信息。并将样方内的各种植物分种齐地面刈割，带回实验室内, 在恒温干燥箱内65℃条件下烘干至恒重, 测定植物样本的干重，计算样方地上生物量。 此外，还通过采样点的经度纬度提取了该52个样点的2种遥感净初级生产力数据。(1) 2000-2018年的增强型植被指数(EVI)，并计算年整合增强型植被指数(iEVI)，iEVI与净初级生产力(NPP)具有高相关性，可作为净初级生产力的替代指标(He et al. 2021, Science of The Total Environment)。(2) 2001-2020年遥感净初级生产力(NPP)及其质量控制百分比(QC)，遥感NPP数据来自MOD17A3HGF Version 6 product (https://lpdaac.usgs.gov/products/mod17a3hgfv006/)，由净光合值（总初级生产力-植物维持呼吸）计算得到。植被覆盖度低的样点，遥感净初级生产力可能存在空值(NA)。

Field surveys were conducted at 52 sampling sites in the desert zones of Qinghai and Tibet. Above-ground biomass of vegetation was sampled during the peak vegetation growth periods from July to August in 2019 and 2020. Meanwhile, longitude, latitude and elevation of each sampling site were recorded using a handheld GPS device.

The field quadrat setup method was as follows: For plots with relatively lush vegetation, a 10 m × 10 m square quadrat was established; for plots with relatively sparse vegetation, a 30 m × 30 m square quadrat or a 30 m × 90 m rectangular quadrat was used. Then, 3 to 5 small 1 m × 1 m quadrats were randomly thrown within the established large quadrat. Plant samples were collected via the quadrat harvesting method: within each 1 m² quadrat, the species names and the number of individuals of each species were recorded. All plants in the quadrat were cut at ground level by species, transported back to the laboratory, oven-dried to constant weight at 65℃ in a constant-temperature drying oven, and the dry weight of each plant sample was measured to calculate the above-ground biomass of the large quadrat.

In addition, two types of remote sensing net primary productivity (NPP) data for the 52 sampling sites were extracted based on their longitude and latitude:
1. Enhanced Vegetation Index (EVI) data from 2000 to 2018, based on which the annual integrated enhanced vegetation index (iEVI) was calculated. iEVI is highly correlated with NPP and can be used as a surrogate indicator for NPP (He et al. 2021, *Science of The Total Environment*).
2. Remote sensing NPP data and its quality control percentage (QC) from 2001 to 2020. The remote sensing NPP data were derived from the MOD17A3HGF Version 6 product (https://lpdaac.usgs.gov/products/mod17a3hgfv006/), which was calculated as net photosynthetic value (gross primary productivity minus plant maintenance respiration). Note that remote sensing NPP may have null values (NA) for sampling sites with low vegetation coverage.

搜集汇总

背景与挑战

背景概述

该数据集提供了2000年至2020年青藏高原荒漠区域52个样点的植被生产力数据，包括2019年和2020年实地测量的植物地上生物量，以及基于遥感技术提取的增强型植被指数和净初级生产力数据。数据集具有年时间分辨率和10km-100km的空间分辨率，旨在支持荒漠生态系统研究和气候变化影响分析。