Saccharum spontaneum biomass and associated soil and foliar nutrient data

Invasive C4 grasses that colonize tropical landscapes abandoned from use for intensive grazing and agriculture can inhibit natural regeneration of secondary forest. In Panama, dense stands of Saccharum spontaneum require active forest restoration to re-establish successional processes. In this region, restoration strategies typically involve clearing grass cover and applying fertilizer prior to planting tree seedlings. However, if fertilizers alleviate nutrient limitation in the grasses and enhance their competition with tree seedlings, it can add to costs for manual maintenance of the sites free of Saccharum. Here we evaluated how S. spontaneum responds to nitrogen and phosphorus addition in the field to determine whether S. spontaneum is nutrient limited in this system. S. spontaneum was both nitrogen and phosphorus as revealed through increased foliar nutrient concentrations. S. spontaneum biomass was significantly greater in both nitrogen and phosphorus addition plots after both the..., This experiment consisted of twelve blocks, each with four nutrient treatments:  no nutrient addition (control; C), N addition (N), P addition (P), and N+P combination (N+P). Plots were 5 x 5 m2, with a 2-m buffer between plots within a block, and a 3-m buffer between blocks. Dry fertilizer was added by hand after clearing S. spontaneum in July. Nitrogen was added as urea ((NH2)2CO2), and phosphorus was added as triple super phosphate (Ca(H2PO4)2•H2O). Nutrient application corresponded to 125 kg ha-1 N and 50 kg ha-1 P, as recommended for this region.  Nutrients were applied after clearing the site in July and again in October, after the first biomass harvest. Soil cores were taken at the end of the study (December) from each plot to compare final soil nutrient availability across treatments. We assessed S. spontaneum performance, in terms of density and above-ground biomass, in September and December 2011. Additionally, in December we collected soil and leaf nutrient data to compare nu..., Data are in a .csv file that can be opened with any spreadsheet or R.Â

入侵性C4草本植物若定植于因集约化放牧与农业开垦而废弃的热带生境中，会抑制次生林的自然更新过程。在巴拿马地区，连片密生的甜根子草（Saccharum spontaneum）需要通过人工森林恢复措施才能重新建立群落演替过程。该区域常见的森林恢复策略通常为：在栽植林木幼苗前，先清除草本覆盖物并施加肥料。然而，若肥料缓解了草本植物的养分限制并增强其与林木幼苗的竞争能力，则会增加人工清除该区域甜根子草的维护成本。本研究通过野外试验探究甜根子草对氮（Nitrogen）、磷（Phosphorus）添加的响应，以明确该生境下甜根子草是否存在养分限制。经叶片养分浓度升高的结果证实，甜根子草同时受氮与磷的限制。在施加氮与磷的样地中，甜根子草的生物量均显著升高，该结果在[...]之后均得到验证。本试验共设置12个区组，每个区组包含4种养分处理：无养分添加（对照组，C）、单施氮处理（N）、单施磷处理（P）以及氮磷配施处理（N+P）。每个样地面积为5×5平方米，区组内部的样地间设置2米缓冲带，区组间设置3米缓冲带。于7月清除甜根子草后，人工施加固态肥料。氮肥采用尿素（(NH2)2CO2）施加，磷肥采用重过磷酸钙（Ca(H2PO4)2·H2O）施加。按照该区域的推荐用量，养分施加量为125 kg·ha⁻¹的氮与50 kg·ha⁻¹的磷。分别于7月清理样地后、首次生物量收获后的10月两次施加养分。于试验结束时（12月）从每个样地采集土芯，以比较不同处理间最终的土壤养分有效性。我们于2011年9月与12月分别评估了甜根子草的生长表现，评估指标包括种群密度与地上生物量。此外，我们于12月采集土壤与叶片样品以开展养分数据对比[...]。数据集存储于.csv格式文件中，可通过任意电子表格软件或R语言打开。