Browsing by Author "Inderjit"
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- ItemDrivers of the relative richness of naturalized and invasive plant species on Earth(Oxford University Press, 2019) Essl, F.; Dawson, W; Kreft, H.; Pergl, J.; Pysek, P.; Van Kleunen, M.; Weigelt, P.; Mang, T.; Dullinger, S.; Lenzner, B.; Moser, D.; Maurel, N.; Seebens, H.; Stein, A.; Weber, E.; Chatelain, C.; Inderjit; Genovesi, P.; Kartesz, J.; Morozova, O.; Nishino, M.; Nowak, P.; Pagad, S.; Shu, W.-S.; Winter, M.Biological invasions are a defining feature of the Anthropocene, but the factors that determine the spatially uneven distribution of alien plant species are still poorly understood. Here, we present the first global analysis of the effects of biogeographic factors, the physical environment and socio-economy on the richness of naturalized and invasive alien plants. We used generalized linear mixed-effects models and variation partitioning to disentangle the relative importance of individual factors, and, more broadly, of biogeography, physical environment and socio-economy. As measures of the magnitude of permanent anthropogenic additions to the regional species pool and of species with negative environmental impacts, we calculated the relative richness of naturalized (= RRN) and invasive (= RRI) alien plant species numbers adjusted for the number of native species in 838 terrestrial regions. Socio-economic factors (per-capita gross domestic product (GDP), population density, proportion of agricultural land) were more important in explaining RRI (~50 % of the explained variation) than RRN (~40 %). Warm-temperate and (sub)tropical regions have higher RRN than tropical or cooler regions. We found that socio-economic pressures are more relevant for invasive than for naturalized species richness. The expectation that the southern hemisphere is more invaded than the northern hemisphere was confirmed only for RRN on islands, but not for mainland regions nor for RRI. On average, islands have ~6-fold RRN, and >3-fold RRI compared to mainland regions. Eighty-two islands (=26 % of all islands) harbour more naturalized alien than native plants. Our findings challenge the widely held expectation that socio-economic pressures are more relevant for plant naturalization than for invasive plants. To meet international biodiversity targets and halt the detrimental consequences of plant invasions, it is essential to disrupt the connection between socio-economic development and plant invasions by improving pathway management, early detection and rapid response.
- ItemInsights on the persistence of pines (Pinus species) in the Late Cretaceous and their increasing dominance in the Anthropocene(Wiley Open Access, 2018) Singh, Surendra P.; Inderjit; Singh, Jamuna S.; Majumdar, Sudipto; Moyano, Jaime; Nuiez, Martin A.; Richardson, David M.ENGLISH ABSTRACT: Although gymnosperms were nearly swept away by the rise of the angiosperms in the Late Cretaceous, conifers, and pines (Pinus species) in particular, survived and regained their dominance in some habitats. Diversification of pines into fire‐avoiding (subgenus Haploxylon) and fire‐adapted (subgenus Diploxylon) species occurred in response to abiotic and biotic factors in the Late Cretaceous such as competition with emerging angiosperms and changing fire regimes. Adaptations/traits that evolved in response to angiosperm‐fuelled fire regimes and stressful environments in the Late Cretaceous were key to pine success and are also contributing to a new “pine rise” in some areas in the Anthropocene. Human‐mediated activities exert both positive and negative impacts of range size and expansion and invasions of pines. Large‐scale afforestation with pines, human‐mediated changes to fire regimes, and other ecosystem processes are other contributing factors. We discuss traits that evolved in response to angiosperm‐mediated fires and stressful environments in the Cretaceous and that continue to contribute to pine persistence and dominance and the numerous ways in which human activities favor pines.
- ItemThe world needs BRICS countries to build capacity in invasion science(Public Library of Science, 2019-09-19) Measey, John; Visser, Vernon; Dgebuadze, Yury; Inderjit; Li, Bo; Dechoum, Michele; Ziller, Silvia R.; Richardson, David M.Developed countries are producing policies to reduce the flow of invasive species and control or eradicate existing invasions, but most developing countries are under-resourced to tackle either aspect without help. Emerging economies, such as Brazil, Russia, India, China, and South Africa (BRICS), are responsible for donating many of the world’s invasive species that have the potential to reach nearly all terrestrial biomes. Implementing a proactive ‘facilitated network’ model is urgently required to build capacity and stimulate effective appropriate invasion science. We contend that creating a BRICS network of invasion scientists will have the immediate impact required to meet future policy demands.