A survey of vascular plant species in paired shrub and open microsites in southern California drylands

We conducted vegetation surveys across several sites in southern California drylands in early spring 2023 to identify patterns in plant diversity across habitat types and an aridity gradient. Locations sampled include sites in Carrizo Plains National Monument, Cuyama Valley, and sites near Tecopa and Semitropic. Surveys were conducted at two spatial scales - 1m x 1m2 paired quadrats and 1m x 10m transects. All plants in 1m2 quadrats and 10m2 transect were identified to species. In quadrats, all individuals were counted, while in transects total percent cover was estimated. Quadrats were placed under randomly selected shrubs and a paired open plot in shrub habitats, and randomly selected paired locations in open habitats. The dominant shrub species was Ephedra californica at most sites. This survey continues long-term vegetation tracking in California drylands aimed at understanding how foundational species influence regional plant diversity.

本研究于2023年早春在加利福尼亚州南部干旱区的多个样地开展植被调查，旨在探明不同生境类型与干旱梯度下的植物多样性分布格局。本次调查的样地涵盖卡里佐平原国家纪念地（Carrizo Plains National Monument）、库亚马谷（Cuyama Valley）以及特科帕（Tecopa）与塞米特罗皮克（Semitropic）周边区域。
调查采用两种空间尺度开展：1米×1米的成对样方（quadrat）与1米×10米的样带（transect）。1㎡样方与10㎡样带内的所有植物均被鉴定至物种水平。在样方中统计所有植株个体数量，而在样带中则估算总盖度。在灌丛生境中，样方设置于随机选取的灌丛下方及其配对的开阔样地；在开阔生境中，则设置于随机选取的配对样点。多数样地的优势灌丛物种为Ephedra californica。本次调查延续了加利福尼亚州干旱区的长期植被监测工作，旨在阐明建群物种对区域植物多样性的影响机制。