Germination and early establishment of dryland grasses and shrubs on intact and wind-eroded soils under greenhouse conditions
Germination and early establishment of dryland grasses and shrubs on intact and wind-eroded soils under greenhouse conditions
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温室条件下完整和风蚀土壤上旱地草和灌木的发芽和早期建立
DOI：
10.1007/s11104-021-05005-9
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发表时间：
2021
期刊：
影响因子：
4.9
通讯作者：
Okin, Gregory S.
中科院分区：
文献类型：
--
作者：
Niu, Furong;Pierce, Nathan A.;Archer, Steven R.;Okin, Gregory S.
目标草地向灌木丛的转变是全世界旱地土地退化的常见形式。这通常归因于干扰制度的变化，特别是过度放牧。放牧的无数直接和间接影响（例如加速水土流失）可能有利于灌木而不是草，但它们的相对重要性尚不清楚。我们测试了这样的假设，即风蚀造成的表土“风选”会对草和灌木幼苗的建立产生不同的影响，从而促进灌木的补充而不是草。方法我们在现场收集的数据上监测了对比多年生草本（Bouteloua eriopoda、Sporobolus airoides 和 Aristida purpurea）和灌木（Prosopis mudulosa、Atriplex canescens 和 Larrea tridentata）功能组的发芽和幼苗生长。结果与风选土壤相比，非风选土壤质地更细，养分含量更高，但根据解吸曲线，风选土壤具有更多的植物可利用水分。与预期相反，在给定物种内，风选和非风选土壤上的种子发芽和幼苗生长具有可比性。固氮落叶灌木P。腺花最先出现并完成发芽，并且在所有物种中具有最大的生物量积累。结论与在浇水良好的温室条件下在非风选土壤上观察到的相比，风选土壤上的草和灌木的发芽和早期幼苗生长没有受到不利或差异性影响。早期发芽和快速生长可能会产生 P.在放牧草地的建立阶段，腺树比草和其他灌木物种具有竞争优势。需要进行实地实验来证实我们在这些受控环境试验中的发现。
AimsGrassland-to-shrubland transition is a common form of land degradation in drylands worldwide. It is often attributed to changes in disturbance regimes, particularly overgrazing. A myriad of direct and indirect effects (e.g., accelerated soil erosion) of grazing may favor shrubs over grasses, but their relative importance is unclear. We tested the hypothesis that topsoil “winnowing” by wind erosion would differentially affect grass and shrub seedling establishment to promote shrub recruitment over that of grass.MethodsWe monitored germination and seedling growth of contrasting perennial grass (Bouteloua eriopoda,Sporobolus airoides, andAristida purpurea) and shrub (Prosopis glandulosa,Atriplex canescens, andLarrea tridentata) functional groups on field-collected non-winnowed and winnowed soils under well-watered greenhouse conditions.ResultsNon-winnowed soils were finer-textured and had higher nutrient contents than winnowed soils, but based on desorption curves, winnowed soils had more plant-available moisture. Contrary to expectations, seed germination and seedling growth on winnowed and non-winnowed soils were comparable within a given species. The N2-fixing deciduous shrubP. glandulosawas first to emerge and complete germination, and had the greatest biomass accumulation of all species.ConclusionsGermination and early seedling growth of grasses and shrubs on winnowed soils were not adversely nor differentially affected comparing with that observed on non-winnowed soils under well-watered greenhouse conditions. Early germination and rapid growth may giveP. glandulosaa competitive advantage over grasses and other shrub species at the establishment stage in grazed grasslands. Field establishment experiments are needed to confirm our findings in these controlled environment trials.
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DOI：
--
发表时间：
1992
期刊：
影响因子：
--
作者：
James A. Young;Cheryl G. Young
通讯作者：
Cheryl G. Young
影响因子：
3.7
作者：
Nathan A. Pierce;S. Archer;B. Bestelmeyer;D. James
通讯作者：
Nathan A. Pierce;S. Archer;B. Bestelmeyer;D. James
影响因子：
10.1
作者：
Okin, Gregory S.;Sala, Osvaldo E.;Bhattachan, Abinash
通讯作者：
Bhattachan, Abinash
影响因子：
2.6
作者：
Alvarez, Lorelei J.;Epstein, Howard E.;Li, Junran;Okin, Gregory S.
通讯作者：
Okin, Gregory S.
影响因子：
5.2
作者：
Nathan A. Pierce;S. Archer;B. Bestelmeyer
通讯作者：
Nathan A. Pierce;S. Archer;B. Bestelmeyer