Background and Aims It is frequently assumed that phenotypic plasticity can be very advantageous for plants, because it may increase environmental tolerance (fitness homeostasis). This should, however, only hold for plastic responses that are adaptive, i.e. increase fitness. Numerous studies have shown shade-induced increases in specific leaf area (SLA), and there is wide consensus that this plastic response optimizes light capture and thus has to be adaptive. However, it has rarely been tested whether this is really the case.Methods In order to identify whether SLA plasticity does contribute to the maintenance of high biomass of plant species under shaded conditions, a meta-analytical approach was employed. The data set included 280 species and 467 individual studies from 32 publications and two unpublished experiments.Key Results Plants increased their SLA by 55Á4 % on average when shaded, while they decreased their biomass by 59Á9 %. Species with a high SLA under high-light control conditions showed a significantly greater ability to maintain biomass production under shade overall. However, in contrast to the expectation of a positive relationship between SLA plasticity and maintenance of plant biomass, the results indicated that species with greater SLA plasticity were less able to maintain biomass under shade.Conclusions Although a high SLA per se contributes to biomass homeostasis, there was no evidence that plasticity in SLA contributes to this. Therefore, it is argued that some of the plastic changes that are frequently thought to be adaptive might simply reflect passive responses to the environment, or result as by-products of adaptive plastic responses in other traits.
Most naturalised and invasive alien plant species were originally introduced to regions for horticultural purposes. However, many regions now face an invasion debt from ornamental alien species, which have not yet naturalised. In this regard, climate change represents a threat as it may lower the barriers to naturalisation for some ornamental alien species. Identifying those species is extremely important for anticipating impending invasions. To identify predictors of naturalisation, we modelled the effects of climate, nursery availability and species characteristics on the current European naturalisation success of 2,073 ornamental aliens commonly planted in European gardens. We then used the resulting model together with climate projections for 2050 to forecast future naturalisation risks for the 1,583 species not yet naturalised in Europe. We found that non‐European naturalised range size, climatic suitability, propagule pressure, having a dioecious sexual system and plant height jointly explained current naturalisation success in Europe. By 2050, naturalisation probability projections increased by more than 0.1 for 41 species, and only decreased by more than 0.1 for one species. Policy implications. Using predictions based on our integrated model of alien ornamental naturalisation success, we identified species with high future naturalisation risk and species with high projected increases in naturalisation potential in Europe under climate change. This species list allows for prioritisation of monitoring and regulation of ornamental plants to mitigate the invasion debt.
(2017) 'The eects of climate warming and disturbance on the colonization potential of ornamental alien plant species.', Journal of ecology., 105 (6). pp. 1698-1708. Further information on publisher's website:https://doi.org/10.1111/1365-2745.12798 Publisher's copyright statement: This is the accepted version of the following article: Haeuser, E., Dawson, W. van Kleunen, M. (2017). The eects of climate warming and disturbance on the colonization potential of ornamental alien plant species. Journal of Ecology., which has been published in nal form at https://doi.org/10.1111/1365-2745.12798. This article may be used for non-commercial purposes in accordance With Wiley Terms and Conditions for self-archiving.Additional information: Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders. Accepted ArticleThis article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Accepted ArticleThis article is protected by copyright. All rights reserved.the current invasion potential of many alien ornamental species. However, with ongoing disturbance and climate change, this barrier may be reduced for some species. 2.Here we tested how colonization ability (a prerequisite for invasion) of frequently planted alien ornamentals depends on disturbance and heating, and on their species characteristics.We sowed seeds of 37 non-naturalized alien herbaceous garden-plant species into native grassland plots with and without disturbance, and with and without infrared heating lamps.To assess whether their responses differ from those within the regional wild flora, we also sowed 14 native species and 12 naturalized alien species. During two years, we assessed the likelihoods of germination, first-year survival, second-year survival and flowering of these 63 study species.3. The heating treatment, which also reduced soil moisture, decreased all measures of colonization success, but more so for sown native species than for the non-naturalized and naturalized alien ones. The disturbance treatment increased colonization success, and because heating decreased productivity of the undisturbed grassland plots, it also increased invasibility of these plots. Average colonization success of non-naturalized aliens was reduced by heating, but some species were not affected or performed even better with heating, particularly those with an annual life span and a high seed mass. Winter hardiness improved colonization ability of non-naturali...
Ornamental horticulture is the most important pathway for alien plant introductions worldwide, and consequently, invasive spread of introduced plants often begins in urban areas. Although most introduced ornamental garden-plant species are locally not naturalized yet, many of them have shown invasion potential elsewhere in the world, and might naturalize when climate changes. We inventoried the planted flora of 50 public and 61 private gardens in Radolfzell, a small city in southern
Introduction HIV planning requires granular estimates for the number of people living with HIV (PLHIV), antiretroviral treatment (ART) coverage and unmet need, and new HIV infections by district, or equivalent subnational administrative level. We developed a Bayesian small‐area estimation model, called Naomi, to estimate these quantities stratified by subnational administrative units, sex, and five‐year age groups. Methods Small‐area regressions for HIV prevalence, ART coverage and HIV incidence were jointly calibrated using subnational household survey data on all three indicators, routine antenatal service delivery data on HIV prevalence and ART coverage among pregnant women, and service delivery data on the number of PLHIV receiving ART. Incidence was modelled by district‐level HIV prevalence and ART coverage. Model outputs of counts and rates for each indicator were aggregated to multiple geographic and demographic stratifications of interest. The model was estimated in an empirical Bayes framework, furnishing probabilistic uncertainty ranges for all output indicators. Example results were presented using data from Malawi during 2016–2018. Results Adult HIV prevalence in September 2018 ranged from 3.2% to 17.1% across Malawi's districts and was higher in southern districts and in metropolitan areas. ART coverage was more homogenous, ranging from 75% to 82%. The largest number of PLHIV was among ages 35 to 39 for both women and men, while the most untreated PLHIV were among ages 25 to 29 for women and 30 to 34 for men. Relative uncertainty was larger for the untreated PLHIV than the number on ART or total PLHIV. Among clients receiving ART at facilities in Lilongwe city, an estimated 71% (95% CI, 61% to 79%) resided in Lilongwe city, 20% (14% to 27%) in Lilongwe district outside the metropolis, and 9% (6% to 12%) in neighbouring Dowa district. Thirty‐eight percent (26% to 50%) of Lilongwe rural residents and 39% (27% to 50%) of Dowa residents received treatment at facilities in Lilongwe city. Conclusions The Naomi model synthesizes multiple subnational data sources to furnish estimates of key indicators for HIV programme planning, resource allocation, and target setting. Further model development to meet evolving HIV policy priorities and programme need should be accompanied by continued strengthening and understanding of routine health system data.
Background Human immunodeficiency virus (HIV) remains a public health priority in Latin America. While the burden of HIV is historically concentrated in urban areas and high-risk groups, subnational estimates that cover multiple countries and years are missing. This paucity is partially due to incomplete vital registration (VR) systems and statistical challenges related to estimating mortality rates in areas with low numbers of HIV deaths. In this analysis, we address this gap and provide novel estimates of the HIV mortality rate and the number of HIV deaths by age group, sex, and municipality in Brazil, Colombia, Costa Rica, Ecuador, Guatemala, and Mexico. Methods We performed an ecological study using VR data ranging from 2000 to 2017, dependent on individual country data availability. We modeled HIV mortality using a Bayesian spatially explicit mixed-effects regression model that incorporates prior information on VR completeness. We calibrated our results to the Global Burden of Disease Study 2017. Results All countries displayed over a 40-fold difference in HIV mortality between municipalities with the highest and lowest age-standardized HIV mortality rate in the last year of study for men, and over a 20-fold difference for women. Despite decreases in national HIV mortality in all countries—apart from Ecuador—across the period of study, we found broad variation in relative changes in HIV mortality at the municipality level and increasing relative inequality over time in all countries. In all six countries included in this analysis, 50% or more HIV deaths were concentrated in fewer than 10% of municipalities in the latest year of study. In addition, national age patterns reflected shifts in mortality to older age groups—the median age group among decedents ranged from 30 to 45 years of age at the municipality level in Brazil, Colombia, and Mexico in 2017. Conclusions Our subnational estimates of HIV mortality revealed significant spatial variation and diverging local trends in HIV mortality over time and by age. This analysis provides a framework for incorporating data and uncertainty from incomplete VR systems and can help guide more geographically precise public health intervention to support HIV-related care and reduce HIV-related deaths.
Across the globe, invasive alien species cause severe environmental changes, altering species composition and ecosystem functions. So far, mountain areas have mostly been spared from large-scale invasions. However, climate change, land-use abandonment, the development of tourism and the increasing ornamental trade will weaken the barriers to invasions in these systems. Understanding how alien species will react and how native communities will influence their success is thus of prime importance in a management perspective. Here, we used a spatially and temporally explicit simulation model to forecast invasion risks in a protected mountain area in the French Alps under future conditions. We combined scenarios of climate change, land-use abandonment and tourism-linked increases in propagule pressure to test if the spread of alien species in the region will increase in the future. We modelled already naturalized alien species and new ornamental plants, accounting for interactions among global change components, and also competition with the native vegetation. Our results show that propagule pressure and climate change will interact to increase overall species richness of both naturalized aliens and new ornamentals, as well as their upper elevational limits and regional range-sizes. Under climate change, woody aliens are predicted to more than double in range-size and herbaceous species to occupy up to 20% of the park area. In contrast, land-use abandonment will open new invasion opportunities for woody aliens, but decrease invasion probability | MATERIALS AND METHODS | Study areaWe focused on a protected mountain area in the French Alps (Ecrins National Park-ENP), which covers 270,000 ha and is characterized by large environmental and altitudinal gradients (650-4,100 m a.s.l.), with lower altitudes mostly at the peripheries of the park (Fig. S1).The ENP is located at the crossroads of temperate and Mediterranean climates and harbours ca. 2,000 vascular plant species, with so far only very few occurrences of alien species. Currently, twothirds of the park consist of open habitats, managed mostly through traditional agro-pastoral practices such as extensive grazing (80%) and/or mowing (25%), while forests cover ca. 25% of the area. The department Hautes-Alpes (where the ENP is located) is currently the third least populated in France, but since 2006 its population has increased by ca. 1.2% each year, more than twice the national average (Insee, 2014), supporting more than 360,000 tourist beds.Within the department, the ENP is in itself a tourist destination, supported by a network of 740 km of mountain trails and more than 30 mountain huts. | Hybrid simulation modelWe used the spatially explicit hybrid model FATE-HD to simulate spatio-temporal dynamics of resident vegetation and plant invasions under different global change scenarios Boulangeat, Georges, Dentant, et al., 2014). FATE-HD combines species distribution models (SDMs) with process-based modelling to simulate population dynamics (dispersal, germinat...
Questions: Is rock climbing pressure, together with microtopographic conditions, disturbing cliff plant cover and composition? What are the climbing impacts on rock specialist and non-specialist species? Can a case-control approach, not previously implemented in cliff environments, offer additional value for actual and long-term ecological research?Location: Chulilla, Levante coast, Spain. Methods:We surveyed in situ nine rock climbing routes in order to examine differences in plant species richness and vegetation cover between unclimbed and climbed transects. To evaluate the effect of rock climbing on vegetation, we implemented a case-control methodology using the two zones immediately adjacent to common climbing routes as control points (i.e. unclimbed transects). Three quadrats of 3 m × 3 m were established at different cliff heights. All identified species were categorized as either specialized rock species or non-specialized rock species based on their habitat preferences from literature. Non-specialized rock species were further differentiated as either moderately associated with rocky environments or strict generalists. The rock climbing impact on each group of species was analysed using LMM. Results:Our results provide evidence of the effects of rock climbing on a Mediterranean cliff, which has received little attention so far. Significantly fewer generalist species were present on climbed compared to unclimbed transects, while specialized and moderately specialized rock species were not significantly affected by rock climbing intensity. Furthermore, while rock-specific and moderately specialized species could cope with microsite heterogeneity, areas with fewer cracks had significantly negative effects on generalist species. Conclusions:Moderate rock climbing activity on cliff environments might not reduce the presence of specialized rock-dwelling species; however, this activity inherently impacts the biodiversity of cliff ecosystems due to its large effect on generalist species. We recommend that future conservation studies account for the degree of species dependence on rocky habitats to better understand rock-climbing impacts in these singular ecosystems. According to our experience, the implementation of an
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