We currently face both an extinction and a biome crisis embedded in a changing climate. Many biodiverse ecosystems are being lost at far higher rates than they are being protected or ecologically ...restored. At the same time, natural climate solutions offer opportunities to restore biodiversity while mitigating climate change. The Bonn Challenge is a U.N. programme to restore biodiversity and mitigate climate change through restoration of the world's degraded landscapes. It provides an unprecedented chance for ecological restoration to become a linchpin tool for addressing many environmental issues. Unfortunately, the Forest and Landscape Restoration programme that underpins the Bonn Challenge, as its name suggests, remains focused on trees and forests, despite rising evidence that many non‐forest ecosystems also offer strong restoration potential for biodiversity and climate mitigation. We see a need for restoration to step back to be more inclusive of different ecosystem types and to step up to provide integrated scientific knowledge to inform large‐scale restoration. Stepping back and up will require assessments of where to restore what species, with recognition that in many landscapes multiple habitat types should be restored. In the process, trade‐offs in the delivery of different ecosystem services (e.g. carbon, biodiversity, water, albedo, livestock forage) should be clearly addressed. We recommend that biodiversity safeguards be included in policy and implemented in practice, to avoid undermining the biophysical relationships that provide ecosystem resilience to climate change. For ecological restoration to contribute to international policy goals will require integrated large‐scale science that works across biome boundaries.
Biological invasions are a major environmental challenge today. Interactions between invasive and native species can significantly shape community structures, influencing coexistence, diversity and ...functional composition of species. The subtropical Atlantic Forest in southern Brazil, a recognized biodiversity hotspot, provides a unique setting to study these interactions, given its vulnerability to alien tree invasions.
Our study sought to elucidate the impacts of such invasions on this fragile ecosystem by addressing key questions: (1) How are tree community diversity patterns affected by the abundance of invading alien tree species? (2) What are the patterns of coexistence between native and alien invasive trees? (3) Is the functional composition of the forests altered by the abundance of invasive trees?
To address these questions, we compiled data on the abundance and functional traits of native and invasive trees. We determined the diversity patterns and functional composition of plots with different degrees of invasion. These data were analysed using generalized linear mixed models, principal component analysis and a coexistence index.
In plots with a higher abundance of invasive trees, there was a significant decrease in the taxonomic and functional richness (FRic) of native species. Furthermore, we observed that invasive alien trees coexisted with native species, and as the abundance of invasive trees increased, the native community‐weighted mean of the leaf area (LA) and specific leaf area (SLA) decreased.
In conclusion, within the subtropical Atlantic Forest areas of southern Brazil, our findings highlight that the abundance of invasive trees adversely affects the taxonomic and FRic of native species. Furthermore, while invasive alien trees were found to coexist with native species, increased invasive abundance corresponded to a reduction in the LA and the SLA of the native community.
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Resumo
Invasões biológicas são um grande desafio ambiental atualmente. Interações entre espécies invasoras e nativas podem moldar significativamente as estruturas da comunidade, influenciando a coexistência, diversidade e composição funcional das espécies. A Floresta Atlântica subtropical no sul do Brasil, um reconhecido hotspot de biodiversidade, oferece um cenário único para estudar essas interações, dada sua vulnerabilidade às invasões de árvores exóticas.
Nosso estudo buscou elucidar os impactos dessas invasões neste ecossistema frágil, abordando questões‐chave: (1) Como os padrões de diversidade da comunidade arbórea são afetados pela abundância de espécies exóticas invasoras? (2) Quais são os padrões de coexistência entre árvores nativas e exóticas invasoras? (3) A composição funcional das florestas é alterada pela abundância de árvores invasoras?
Para abordar essas questões, compilamos dados sobre a abundância e características funcionais de árvores nativas e invasoras. Determinamos os padrões de diversidade e composição funcional de parcelas com diferentes graus de invasão. Estes dados foram analisados usando Modelos Lineares Mistos Generalizados, Análise de Componentes Principais e um índice de coexistência.
Em parcelas com maior abundância de árvores invasoras, houve uma diminuição significativa na riqueza taxonômica e funcional das espécies nativas. Além disso, observamos que árvores exóticas invasoras coexistiam com espécies nativas, e à medida que a abundância de árvores invasoras aumentava, a média ponderada da comunidade nativa (CWM) da área foliar e da área foliar específica diminuía.
Em conclusão, nas áreas da Floresta Atlântica subtropical do sul do Brasil, nossos achados destacam que a abundância de árvores invasoras afeta adversamente a riqueza taxonômica e funcional das espécies nativas. Além disso, enquanto árvores exóticas invasoras foram encontradas coexistindo com espécies nativas, o aumento da abundância invasora correspondeu a uma redução na área foliar e na área foliar específica da comunidade nativa.
Read the free Plain Language Summary for this article on the Journal blog.
In times of unprecedented climate change, ecological restoration efforts have a strong focus on forests for the purpose of carbon sequestration. Grasslands, in contrast, remain relatively neglected ...in global restoration policies. Concurrently, we are in the midst of a biodiversity crisis—it is estimated that 1 million species are globally threatened with extinction. Here, we present analyses from central Europe and southern Brazil that show that the majority of our endangered plant species are in fact found in open ecosystems. Using Germany as an example, we show that we could reduce plant extinction risk by up to 82% if we restore open, grassy ecosystems. This also holds true for southern Brazil, where grassland species constitute the single largest share of endangered species, but where grassy ecosystems continue to be systematically neglected by restoration policies. We further expand on our biodiversity argument to include the role that grassland restoration can play in mitigating climate change. We posit that ramping up grassland restoration efforts may not only be our best bet to bend the curve of biodiversity loss, but it will also make a critical contribution to the resilience of ecosystems in the dynamic decades to come. It is time for grassland restoration to receive higher priority in global restoration efforts and policy.
Tropical savannas are known for the fire‐prone ecosystems, yet, riparian evergreen forests are another important landscape feature. These forests usually remain safe from wildfires in the wet ...riparian zones. With global changes, large wildfires are now more frequent in savanna landscapes, exposing riparian forests to unprecedented impact.
In 2017, a large wildfire spread across the Chapada dos Veadeiros National Park, an iconic UNESCO site in central Brazil, raising concerns about its impact on the fire‐sensitive ecosystems. By combining remote sensing analysis of Google Earth images (2003–2019) with detailed field information from 36 sites, we assessed wildfire impacts on riparian forests. For this, we measured the structure of trees, saplings and herbaceous plants, as well as topsoil variables.
Since 2003, all riparian forests had canopy cover above 90%, but after 2017, canopy cover dropped to 20% in some forests, indicating large variation in wildfire damage. A closer look in the field revealed that, on average, the wildfire killed 52% of adult trees and 87% of tree saplings in flooded forests. In non‐flooded forests, impacts on adult trees were negligible, but fire killed 75% of tree saplings. Opportunistic vines and the invasive grass Melinis minutiflora were already present in severely disturbed flooded forests. In all forests, impacts on many ecosystem variables were related to canopy damage, a variable measurable from satellite. Overall, seasonally flooded riparian forests were the most severely impacted, possibly due to the relatively thinner barks of their trees.
Synthesis and applications. Our findings reveal how riparian forests embedded in tropical savanna landscapes are in danger from large wildfires. The destruction of some forests has opened space for new plant species that may propel a shift to an alternative ecosystem state. Riparian forests are habitat of large savanna animals and their loss could affect entire trophic networks. Managing wildfires and invasive grasses locally is probably the best strategy to maintain riparian forests resilient. As wildfire regimes intensify in tropical savanna landscapes, our findings stress the need for an integrated management that considers riparian forests as a vulnerable element of the system.
Our findings reveal how riparian forests embedded in tropical savanna landscapes are in danger from large wildfires. The destruction of some forests has opened space for new plant species that may propel a shift to an alternative ecosystem state. Riparian forests are habitat of large savanna animals and their loss could affect entire trophic networks. Managing wildfires and invasive grasses locally is probably the best strategy to maintain riparian forests resilient. As wildfire regimes intensify in tropical savanna landscapes, our findings stress the need for an integrated management that considers riparian forests as a vulnerable element of the system.
The restoration of areas invaded by non‐native plants is challenging as invasive plants may affect both biotic and abiotic components of ecosystems, leading to impacts that constrain recolonization ...by native species after invaders are eliminated. In such a scenario, restoration techniques as topsoil transposition might accelerate colonization by native species in forests. Hedychium coronarium J. Koenig (Zingiberaceae) is a Himalayan herbaceous rhizomatous plant recognized as invasive in several countries. This study aimed to experimentally evaluate the response of plant assemblages to topsoil transposition on a site invaded by H. coronarium after chemical control. Four treatments were applied: chemical control integrated with topsoil transposition, chemical control of H. coronarium alone, topsoil transposition alone, and no intervention (control). Plots were evaluated prior to the application of treatments and then monthly for 11 months after treatments. Parameters were measured for H. coronarium (number of ramets, ramet height, and cover) and other species (species richness, abundance, and cover). Plots treated with chemical control (regardless of topsoil transposition) were similar in terms of all parameters measured and species composition, with dominance of herbs and shrubs. Plots managed solely with topsoil transposition had lower species richness, abundance, and cover, but more diverse life‐forms, being equally rich in climbers, trees, and herbs. Chemical control was effective to control invasion by H. coronarium and increase species richness and abundance on the managed site. Topsoil transposition promoted colonization by species that might accelerate restoration.
Manipulating plant order of arrival, a process that creates priority effects, may be an unexplored powerful tool to hinder the establishment of invasive non‐native plants in sites under restoration. ...Knowledge and experimental studies on priority effects in the neotropics are scarce. Here, we propose a research agenda that investigates whether manipulating plant order of arrival can create priority effects in the neotropics, and if this strategy can be used to avoid the spread of undesired species in restoration projects. We also describe our view on expanding existing knowledge on priority effects to the neotropics and identifying key questions for future research.
Several tree species are found among the most well-know and impacting invasive plants that produce changes in richness, abundance and composition of native plant species as well as in environmental ...characteristics and ecosystem functioning.
Hovenia dulcis
Thunb. (Rhamnaceae) is a tree native to East Asia, invasive in southern South America in different forest ecosystems. This study was aimed at assessing the effects of
H. dulcis
on richness, abundance and composition of regenerating species in seasonal deciduous forest (SDF) by comparing invaded and non-invaded areas. The existence of correlations between abundance and richness of regenerating species with age and density of the invasive species, as well as with characteristics of canopy openness, litter thickness, slope, and soil moisture, was investigated in areas invaded by
H. dulcis
. Differences observed in canopy openness and litter tickness between areas invaded by
H. dulcis
and control areas suggest that
H. dulcis
is able to change environmental conditions on a local scale. Although no difference was observed in species richness between areas with and without
H. dulcis
, the differences registered in abundance and composition of regenerating species make the impact by
H. dulcis
on regeneration patterns in SDF fragments evident. The impacts caused by
H. dulcis
on SDF confirmed by this study highlight the need for its control in legally protected areas and their immediate surroundings, as well as for the adoption of public policies to promote the substitution of
H. dulcis
for locally native species.
Risk analyses are predictive systems designed to detect the risk of invasion by non‐native species. Although eucalypts are often considered moderately invasive given the extent of cultivation on a ...global scale, some species are widely recognized as invasive for transforming and impacting natural areas in several countries. These problems may be due to propagule pressure derived from human interest in forest production and aesthetic values. Risk analyses were carried out for 16 eucalypt species cultivated in Brazil using a protocol adapted from an Australian model to Brazilian conditions. The species were: Corymbia citriodora, Corymbia maculata, Corymbia torelliana, Eucalyptus benthamii, Eucalyptus brassiana, Eucalyptus camaldulensis, Eucalyptus cloeziana, Eucalyptus dunnii, Eucalyptus globulus, Eucalyptus grandis, Eucalyptus pellita, Eucalyptus robusta, Eucalyptus saligna, Eucalyptus tereticornis, Eucalyptus urophylla and Eucalyptus viminalis. Results indicate high risk for seven species, moderate risk for eight species and low risk for one species. The only low risk species is E. dunnii, while the highest risk scores refer to C. torelliana, E. tereticornis and E. grandis. These results are consistent with the history of invasion of the species around the world and should be considered for plantations especially when investment capacity to prevent and permanently control spread is low or not associated with forest certification standards. Risk analysis is a valid tool for discriminating between species and making decisions on species to be introduced or cultivated. The results of this study show that there are many species that can be cultivated without incurring biological invasions.
The success of invasion by non-native species can be influenced by positive interactions established in the area of introduction. For instance, seed dispersal by birds can increase seed rain, seed ...germination, and, as a consequence, the probability of establishment of new invasion
foci
.
Schefflera arboricola,
an ornamental shrub with fruits largely consumed by birds, is invasive in several countries. To our knowledge, this is the first research project on mechanisms that might explain the success of
S. arboricola
in areas where it is invasive. The main aim of this study was to assess the invasiveness of
S. arboricola
associated with seed dispersal by birds. Fruit availability and frugivory interactions with local birds were registered and the germination percentage of seeds not consumed by birds was compared to the germination of seeds collected from bird feces. Our results show that frugivory and seed dispersal by native birds increase the establishment of
S. arboricola.
In addition, intrinsic species traits such as extended flowering and fruiting, high percentage of seed germination, early germination due to frugivory, and ability to establish in different microhabitats facilitate invasion by
S. arboricola
. Given the intensive horticultural use of
S. arboricola
and seed dispersal interactions with generalist birds, there is an imminent risk of invasion in forest remnants close to wherever
S. arboricola
is cultivated. We recommend that adult plants of
S. arboricola
are eliminated from gardens and semi-natural areas close to protected areas as a prevention measure to avoid invasions and impacts on natural habitats.
This dataset provides the Global Naturalized Alien Flora (GloNAF) database, version 1.2. GloNAF represents a data compendium on the occurrence and identity of naturalized alien vascular plant taxa ...across geographic regions (e.g. countries, states, provinces, districts, islands) around the globe. The dataset includes 13,939 taxa and covers 1,029 regions (including 381 islands). The dataset is based on 210 data sources. For each taxon-by-region combination, we provide information on whether the taxon is considered to be naturalized in the specific region (i.e. has established self-sustaining populations in the wild). Non-native taxa are marked as “alien”, when it is not clear whether they are naturalized. To facilitate alignment with other plant databases, we provide for each taxon the name as given in the original data source and the standardized taxon and family names used by The Plant List Version 1.1 (http://www.theplantlist.org/). We provide an ESRI shapefile including polygons for each region and information on whether it is an island or a mainland region, the country and the Taxonomic Databases Working Group (TDWG) regions it is part of (TDWG levels 1–4). We also provide several variables that can be used to filter the data according to quality and completeness of alien taxon lists, which vary among the combinations of regions and data sources. A previous version of the GloNAF dataset (version 1.1) has already been used in several studies on, for example, historical spatial flows of taxa between continents and geographical patterns and determinants of naturalization across different taxonomic groups. We intend the updated and expanded GloNAF version presented here to be a global resource useful for studying plant invasions and changes in biodiversity from regional to global scales. We release these data into the public domain under a Creative Commons Zero license waiver (https://creativecommons.org/share-your-work/public-domain/cc0/). When you use the data in your publication, we request that you cite this data paper. If GloNAF is a major part of the data analyzed in your study, you should consider inviting the GloNAF core team (see Metadata S1: Originators in the Overall project description) as collaborators. If you plan to use the GloNAF dataset, we encourage you to contact the GloNAF core team to check whether there have been recent updates of the dataset, and whether similar analyses are already ongoing.
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