Complexity responses of Rhododendron species to climate change in China reveal their urgent need for protection

Global climate change has been widely recognized as important factors that threaten biodiversity.Rhododendron species are not only famous woody ornamental plants worldwide but are also indispensable components in alpine and subalpine vegetation in southwest China.However,the geographical distribution ranges response of this broad taxonomic group to future climate change remains not be fully understood.Herein,we studied the impact of climate change on the distribution of Rhododendron species in China by predicting the changes in their suitable habitats,centroid,and species richness under three climate change scenarios(SSP1-2.6,SSP2-4.5 and SSP5-8.5)in the 2090s.The species richness changes of Rhododendrons along altitude were also evaluated.In addition,we calculated the phylogenetic signals of distribution response to climate change.We found that the distribution responses of Rhododendron to climate change have weak phylogenetic signals.In the 2090s,the suitable habitats of about 87%of Rhododendron species will be reduced,77%of Rhododendron species are manifested as northward migration.The high species richness of Rhododendrons tends to migrate to transboundary areas with high altitudes in China.Some Rhododendron species with no concern previously should be taken seriously for their high risk of habitat loss under climate change.Thus,the urgent protection of Rhododendron species under climate change need to be paid more attention than previous acknowledged.We recommend carrying out the reintroduction of endangered species in future suitable habitat,strengthening the protection of transboundary areas with high species richness,and focusing on species with few concerns previously.

A global synthesis of the effectiveness and ecological impacts of management interventions for Spartina species

Invasions by Spartina species pose serious threats to global coastal ecosystems.Although many studies have examined the effectiveness and ecological impacts of invasive Spartina management,no comprehensive global synthesis has been conducted to assess the effects of management on Spartina per se and on wider non-targets.Here,we conducted a global meta-analysis of 3,459 observations from 102 studies to quantify the effects of different management interventions(physical,chemical,biological,and integrated control)on Spartina per se and native biodiversity and environments.We found that physical measures quickly suppressed Spartina but that their effectiveness declined over time.By contrast,chemical measures decreased the abundance and growth of Spartina to a lesser degree in the early stage,but the effectiveness increased over time.Different management measures did not significantly decrease the diversity of native biota on the whole,but native-plant diversity significantly decreased with time after physical control.Different management measures did not affect abiotic factors differently.These results support the use of chemical measures to control invasive Spartina,although their effectiveness would depend on the time since the management intervention.Addressing the problem of Spartina regrowth following physical control requires improved techniques.We hold that initial states of invaders and subsequent environmental changes after management interventions should be weighed in evaluating control efficacy.