Relationship between local-scale topography and vegetation on the invasive C 4 perennial bunchgrass buffelgrass ( Pennisetum ciliare ) size and reproduction
Relationship between local-scale topography and vegetation on the invasive C 4 perennial bunchgrass buffelgrass ( Pennisetum ciliare ) size and reproduction
复制标题
局部尺度地形和植被对入侵C 4 多年生束草水牛草（Pennisetum ciliare）大小和繁殖的关系
DOI：
10.1017/inp.2023.9
复制
发表时间：
2023
影响因子：
1.1
通讯作者：
Gornish, Elise S.
中科院分区：
文献类型：
--
作者：
Hovanes, Katherine A.;Lien, Aaron M.;Baldwin, Elizabeth;Li, Yue M.;Franklin, Kim;Gornish, Elise S.
野麦草[Pennisetum ciliare（L.）Link]是一种入侵性C4多年生丛生草，对美洲和澳大利亚干旱地区的生物多样性构成威胁。地形影响大尺度纤毛虫的发生，但进一步研究局部尺度地形与纤毛虫生长和繁殖之间的关系将是有益的。此外，密度依赖性对纤毛原甲生长和繁殖的影响已在温室实验中得到证实，但密度依赖性对纤毛原甲自然种群的影响程度值得进一步研究。本文研究了局部尺度地形（坡向和坡度）与植被特征（灌木覆盖度、纤毛虫覆盖度和纤毛虫密度）之间的关系及其相互作用对纤毛虫个体大小和繁殖的影响。在美国亚利桑那州图森市Tumamoc山沙漠实验室的11个样带中，对33个4 × 4 m样地的10种纤毛毛白杨植物的坡度、坡向、灌木覆盖度、纤毛毛白杨覆盖度、纤毛毛白杨密度以及活秆和生殖秆总数进行了测量。我们在局部尺度上模拟了（1）纤毛原甲的覆盖和密度与坡向和坡度的关系，以及（2）纤毛原甲的大小和繁殖与非生物（坡度和坡向）和生物（纤毛原甲的覆盖和密度以及原生灌木和仙人掌覆盖）特征的关系。方面和坡度是穷人的预测P.纤毛虫覆盖和密度在已经入侵的网站在我们的地块的规模。而形态与纤毛毛白杨的植株大小和繁殖力有显著的相关性。南坡的狼尾草植株比其他坡的植株更大，产生的生殖秆也更多。此外，我们没有发现纤毛虫密度和纤毛虫的植物大小和繁殖之间的关系。灌木覆盖度与纤毛虫繁殖呈正相关。朝南的方面可能是最容易受到快速传播和填充新的P. ciliare介绍。
Buffelgrass [Pennisetum ciliare (L.) Link] is an invasive C4 perennial bunchgrass that is a threat to biodiversity in aridlands in the Americas and Australia. Topography influences P. ciliare occurrence at large spatial scales, but further investigation into the relationship between local-scale topography and P. ciliare growth and reproduction would be beneficial. Further, density-dependent effects on P. ciliare growth and reproduction have been demonstrated in greenhouse experiments, but the extent to which density dependence influences P. ciliare in natural populations warrants further investigation. Here we present a study on the relationships between local-scale topography (aspect and slope gradient) and vegetation characteristics (shrub cover, P. ciliare cover, and P. ciliare density) and their interactions on individual P. ciliare plant size and reproduction. We measured slope gradient, aspect, shrub cover, P. ciliare cover, P. ciliare density, and the total number of live culms and reproductive culms of 10 P. ciliare plants in 33 4 by 4 m plots located in 11 transects at the Desert Laboratory at Tumamoc Hill, Tucson, AZ, USA. We modeled the relationships at the local scale of (1) P. ciliare cover and density with aspect and slope gradient and (2) P. ciliare size and reproduction with abiotic (slope gradient and aspect) and biotic (P. ciliare cover and density and native shrub and cacti cover) characteristics. Aspect and slope gradient were poor predictors of P. ciliare cover and density in already invaded sites at the scale of our plots. However, aspect had a significant relationship with P. ciliare plant size and reproduction. Pennisetum ciliare plants on south-facing aspects were larger and produced more reproductive culms than plants on other aspects. Further, we found no relationship between P. ciliare density and P. ciliare plant size and reproduction. Shrub cover was positively correlated with P. ciliare reproduction. South-facing aspects are likely most vulnerable to fast spread and infilling by new P. ciliare introductions.