Kenya Long-term Exclosure Experiment (KLEE) Vegetation Data 1999-2013

Herbaceous vegetation in all 18 KLEE plots has been sampled biannually (in February and June) or annually (in June) since 1995. Sampling periods follow rainy periods that are similar in terms of average rainfall. Due to improvements in species identification, pre-1999 surveys are not fully comparable to later data. Each of the eighteen 4 ha KLEE treatment plots contains a central hectare that is divided into a 10 x 10 m grid of 100 sampling stations. Aerial plant cover and composition are assessed at these stations by counting the number of pins hit by each species over a ten-point pin frame (with vertical pins separated by 5 cm; maximum one hit per pin per species). All 100 grid points were sampled 1999-2005, and every fifth grid point (20 per plot) was sampled from 2006 to 2013 (see Fig. 2 for current vegetation sampling layout). <br>This Excel datasheet contains vegetation data from 1999 – 2013. Later surveys have also been conducted and are available upon request. This Excel file is broken into the following sheets: o “Raw data” sheet: Scaled sum first hits data for each year (columns) organized by species, then by treatment and block. This sheet has data for all species.o “Lumped spp.” sheet: Data are lumped together for several species that we decided needed to be treated together. (e.g. Melhania spp.)♣ Standardizing species list:• Aristida spp. Aristida kenyensis• Eragrostis tenuifolia, racemosus and B lumped together• Justicia white and Justicia dichipteroides lumped together• Leucas glabrata and Leucas martinensis lumped together • Lily A and Lily B lumped together• Sedges (Cyperus, Mariscus and Kyllinga) lumped together♣ After lumping, multi-species taxa include:• Commelina spp• Eragrostis spp• Sedges• Hibiscus flavifolius/aponeurus• Leucas spp• Melhania spp• Plectranthus spp • Pseudognaphalium/Helichrysum• Fern (&lt;5%)• Justicia spp (&lt;5%)• Lily spp (&lt;5%)o 5% of surveys sheet: Binary designations for whether a species occurred or not (in each plot in each year). Then calculation of the percentage of “surveys” (plots*time) that species occurred in.o Spp &gt;5 % sheet: first hits for only those species that occurred in at least 5% of all sampled plot*time combinations. <br>

自1995年起，研究人员对全部18个KLEE样地内的草本植被开展系统采样，采样频率为每半年一次（2月与6月）或每年一次（6月），所有采样时段均选在降雨特征相近的雨季之后。由于物种鉴定技术的迭代升级，1999年之前的调查数据与后续采集的数据不具备完全可比性。18个面积为4公顷的KLEE处理样地均设有中心样区，该样区划分为10×10米的网格，共设置100个采样站点。在上述采样站点中，研究人员采用十点针框（垂直针间距为5厘米，每根针上每种植物最多记录一次击针次数），通过计数各物种的击针数来评估地上植被盖度与物种组成。1999年至2005年期间，对全部100个网格点进行了采样；2006年至2013年则仅对每间隔5个的网格点（每个样地20个点）开展采样，当前植被采样布局详见图2。
本Excel数据集包含1999年至2013年的植被调查数据，后续开展的调查数据亦可应研究人员要求提供。该Excel文件包含以下工作表：
• “原始数据”工作表：按物种、处理方式与样地块进行分组，各年份（列）的标准化首次击针汇总数据，涵盖所有物种的相关信息。
• “合并类群”工作表：将经评估后需要合并的多个物种的数据进行合并（例如Melhania属物种）。
♣ 物种列表标准化规则：
• Aristida属物种：合并为Aristida kenyensis
• Eragrostis tenuifolia、Eragrostis racemosus与物种B合并为一类
• Justicia white与Justicia dichipteroides合并为一类
• Leucas glabrata与Leucas martinensis合并为一类
• Lily A与Lily B合并为一类
• 莎草类（Cyperus属、Mariscus属与Kyllinga属）合并为一类
♣ 合并完成后，多物种类群包括：
• Commelina属
• Eragrostis属
• 莎草类
• Hibiscus flavifolius/aponeurus
• Leucas属
• Melhania属
• Plectranthus属
• Pseudognaphalium/Helichrysum
• 蕨类植物（占比＜5%）
• Justicia属物种（占比＜5%）
• Lily属物种（占比＜5%）
• “占比5%抽样”工作表：以二元变量标记各物种在对应年份、对应样地中是否出现，并计算该物种在所有「采样组合（样地×时间）」中出现的比例。
• “物种占比＞5%”工作表：仅包含在至少5%的采样组合（样地×时间）中出现的物种的首次击针数据。