Complex community responses underpin biodiversity change following invasion

ARK thanks Ciência sem Fronteiras/Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) for a fully funded PhD fellowship at the University of St Andrews (1091/13-1) and the School of Biology of the University of St Andrews. ARK acknowledges a Postdoctoral fellowship at the International Institute for Applied Systems Analysis (IIASA) funded by CAPES (88881.308367/2018-01) and AEM thanks the Leverhulme Trust (RPG-2019-402) for support.How do invasive species change native biodiversity? One reason why this long-standing question remains challenging to answer could be because the main focus of the invasion literature has been on shifts in species richness (a measure of alpha-diversity). As the underlying components of community structure-intraspecific aggregation, interspecific density and the species abundance distribution (SAD)-are potentially impacted in different ways during invasion, trends in species richness provide only limited insight into the mechanisms leading to biodiversity change. In addition, these impacts can be manifested in distinct ways at different spatial scales. Here we take advantage of the new Measurement of Biodiversity (MoB) framework to reanalyse data collected in an invasion front in the Brazilian Cerrado biodiversity hotspot. We show that, by using the MoB multi-scale approach, we are able to link reductions in species richness in invaded sites to restructuring in the SAD. This restructuring takes the form of lower evenness in sites invaded by pines relative to sites without pines. Shifts in aggregation also occur. There is a clear signature of spatial scale in biodiversity change linked to the presence of an invasive species. These results demonstrate how the MoB approach can play an important role in helping invasion ecologists, field biologists and conservation managers move towards a more mechanistic approach to detecting and interpreting changes in ecological systems following invasion.Publisher PDFPeer reviewe

Comparative Studies on the Effects of Various Combined-Chemotherapy in the Experimental Tuberculosis

この論文は国立情報学研究所の学術雑誌公開支援事業により電子化されました。海の実験的前眼部結核症を対象として, 30週間にわたつてSM-PAS, INH-SI, INH-PZA, INH-PASの2者併用療法を施行し順序を交替して投与したのと, 終始一貫, SM-INH週2日-PAS毎日の3者併用療法を施行し, その効果を比較検討したことに就いては既に報告したが, 本篇においては各臓器の定量培養により検出された結核菌に就いて, SM, PAS及びINHに対する耐性検査を行なつた。其の結果2者併用療法を交替させた群では耐性の発現は軽度であつた。しかしSM-PAS⟶INH-PASと言う風にPASを終始使用した例では, 主剤を交替しても比較的耐性の発現は高度であつた。3者併用(S_2I_2P毎)を行なつた群ではその中間の成績であつた。併しINHに対する耐性獲得はすべての治療群に殆んど認める事が出来なかつた