Robinia pseudoacacia is one of the most frequent non‐native species in Europe. It is a fast‐growing tree of high economic and cultural importance. On the other hand, it is an invasive species, ...causing changes in soil chemistry and light regime, and consequently altering the plant communities. Previously published models developed for the potential distribution of R. pseudoacacia concerned 2070, and were based mainly on data from Western and Central Europe; here we extended these findings and included additional data from Eastern Europe. To fill the gap in current knowledge of R. pseudoacacia distribution and improve the reliability of forecasts, we aimed to (i) determine the extent to which the outcome of range modeling will be affected by complementing R. pseudoacacia occurrence data with sites from Central, Southeastern, and Eastern Europe, (ii) identify and quantify the changes in the availability of climate niches for 2050 and 2070, and discuss their impacts on forest management and nature conservation. We showed that the majority of the range changes expected in 2070 will occur as early as 2050. In comparison to previous studies, we demonstrated a greater eastward shift of potential niches of this species and a greater decline of potential niches in Southern Europe. Consequently, future climatic conditions will likely favor the occurrence of R. pseudoacacia in Central and Northeastern Europe where this species is still absent or relatively rare. There, controlling the spread of R. pseudoacacia will require monitoring sources of invasion in the landscape and reducing the occurrence of this species. The expected effects of climate change will likely be observed 20 years earlier than previously forecasted. Hence we highlighted the urgent need for acceleration of policies aimed at climate change mitigation in Europe. Also, our results showed the need for using more complete distribution data to analyze potential niche models.
Previously published models of R. pseudoacacia 's potential distribution concerned 2070, and were based on data from Western and Central Europe; here we extended these findings using data from Eastern Europe and 2050. We demonstrated a greater eastward shift of potential niches of this species and a greater decline in Southern Europe. Future climatic conditions will likely favor the occurrence of R. pseudoacacia in Central and Northeastern Europe. The expected effects of climate change will likely be observed 20 years earlier than previously forecasted. Also, our results showed the need for using more complete distribution data to analyze potential niche models.
Although numerous species distribution models have been developed, most were based on insufficient distribution data or used older climate change scenarios. We aimed to quantify changes in projected ...ranges and threat level by the years 2061–2080, for 12 European forest tree species under three climate change scenarios. We combined tree distribution data from the Global Biodiversity Information Facility, EUFORGEN, and forest inventories, and we developed species distribution models using MaxEnt and 19 bioclimatic variables. Models were developed for three climate change scenarios—optimistic (RCP2.6), moderate (RCP4.5), and pessimistic (RPC8.5)—using three General Circulation Models, for the period 2061–2080. Our study revealed different responses of tree species to projected climate change. The species may be divided into three groups: “winners”—mostly late‐successional species: Abies alba, Fagus sylvatica, Fraxinus excelsior, Quercus robur, and Quercus petraea; “losers”—mostly pioneer species: Betula pendula, Larix decidua, Picea abies, and Pinus sylvestris; and alien species—Pseudotsuga menziesii, Quercus rubra, and Robinia pseudoacacia, which may be also considered as “winners.” Assuming limited migration, most of the species studied would face a significant decrease in suitable habitat area. The threat level was highest for species that currently have the northernmost distribution centers. Ecological consequences of the projected range contractions would be serious for both forest management and nature conservation.
We quantified changes in projected ranges and threat level by the years 2061–2080 for 12 European forest tree species under three climate change scenarios and three Global Circulation Models using MaxEnt model. Due to different responses of tree species to projected climate change, species may be divided into “winners” – mostly late‐successional species, “losers” – mostly pioneer species, and alien species. Assuming limited migration, most of the species studied would face significant decrease of suitable habitat area, especially species that currently have the northernmost distribution centers.
We assessed drivers of ecological success along resource availability gradients for three invasive woody species:
Prunus serotina
Ehrh.,
Quercus rubra
L. and
Robinia pseudoacacia
L. We aimed to check ...how much of invasion success, measured by invader biomass, is explained by propagule pressure and plant community invasibility. Using 3 years of observations from 372 study plots (100 m
2
each) in temperate forests of Wielkopolski National Park (Poland) we investigated the hierarchy of predictors and partial dependencies using the random forest method. Our study indicated that propagule pressure explained more variance in success of invaders than invasibility—describing availability of resources and competitors in understory vegetation. We also found different responses of seedlings and saplings, connected with dependence on stored carbohydrates, which decreased seedling responses to resource availability gradients. However, resource availability (light and leaf litter predictors) had greater influence than predictors describing understory vegetation. Based on importance and response strength the species studied may be arranged by decreasing requirements for soil fertility and acidity:
P. serotina
<
Q. rubra
<
R. pseudoacacia
, whereas for light requirements and competition vulnerability the order is:
P. serotina
>
Q. rubra
>
R. pseudoacacia
. However, low light requirements of
R. pseudoacacia
may be biased by high proportion of sprouts supplied by parental trees. Results provide guidelines for effective management of invasive woody species in forest ecosystems and describe complex interactions between factors studied on ecological success of invaders.
We estimated climate niche shifts and threat levels under various climate change scenarios for Vaccinium myrtillus L. and V. vitis-idaea L. We developed the MaxEnt species distribution models, and ...predicted future climatic optima for climate change scenarios for 2041–2060 and 2061–2080. The precipitation of the warmest quarter was the most important factor shaping the climatic niches of the studied species. We predicted the largest shifts in climate niches from the present to the 2040–2060 period, with the most pessimistic scenario predicting significant range losses for both species, mainly in Western Europe. Under the most optimistic SSP126 scenario, both species will lose 39 % of their climatic niche for both periods. In the worst-case scenario (SSP585) for 2061–2080, climatic niche contraction will cover 47 % and 39 % of the current climatic niche for V. myrtillus and V. vitis-idaea, respectively. The predicted changes in species distribution could have far-reaching consequences for temperate and boreal forests due to their crucial biocenotic role in forest ecosystems, high potential for carbon sequestration, and prevention of soil erosion. Furthermore, the changes would likely affect the economic potential regarding fruit production and culturally relevant uses of different parts of the plants, mainly fruits.
Display omitted
•We assessed shifts of climatic optima of Vaccinium myrtillus and V. vitis-idaea.•Precipitation in the warmest quarter was crucial for their distributions.•Climate change will lead to a dramatic loss of the studied species climatic optima.•Fragmentation of studied species' potential niches in southern Europe is expected.•Decline of studied species will affect forest ecosystem services in Europe.
Human pressure on urban landscapes has serious consequences for urban plant species. Therefore, environmental and anthropogenic factors affect the assembly of urban wildlife in plant communities. For ...biodiversity conservation and ecosystem services in urban areas, it is crucial to understand the impacts of urbanization as well as the introduction of alien plant species on urban plant communities. On 47 sites in Poznań (W Poland), we studied variation within and between three management greenery habitats, i.e., urban parks, greenery associated with housing estates, and urban grasslands, as they relate to taxonomical, functional, and phylogenetic alpha and beta diversity. We also examined how urbanization (measured by ISA) and alien plant species relate to vegetation compositional differences. We found that both urbanization and alien plant species cover decreased alpha diversity, while urbanization had various impacts on beta diversity within each studied habitat. Our results suggest that human pressure leads to similarities in the urban flora, where plant species with specific functional traits adapted to the urban environment. To achieve sustainable urbanization, urban planners should not only create diverse green spaces but also eliminate alien plants, increasing the role of urban land management in promoting the wildness of plant biodiversity in cities.
Despite good recognition of distributions and spread mechanisms of the three most invasive trees in Europe (
Prunus serotina
,
Quercus rubra
and
Robinia pseudoacacia
), their impacts on forest ...biodiversity are unevenly recognized. Most studies cover only taxonomic alpha diversity, and only a single study included functional and phylogenetic diversity. Using a set of 186 study plots in western Poland we assessed the impacts of these invasive tree species on the alpha and beta taxonomic, functional and phylogenetic diversity of understory vascular plants. Alpha diversity was higher in
R. pseudoacacia
forests and lower in
Q. rubra
forests compared to mature native forests. Compared to non-invaded plantations and forests, alpha diversity was higher in
P. sylvestris
plantations invaded by
P. serotina
, but lower in invaded nutrient-poor
P. sylvestris
forests. Alien species richness was higher and beta diversity was lower in forests invaded by
P. serotina
or
R. pseudoacacia
than in non-invaded forests. In contrast, beta diversity was higher in
Q. rubra
forests than in native forests. We proved that invaded forests differed from non-invaded forests in species composition, but not always with decreased alpha and beta diversity. Impacts of particular invasive species also depended on the reference ecosystem properties (here mature native forests, which did not always have the highest biodiversity), which is a source of inconsistency in previous studies, usually referring to single native ecosystem types.
Heracleum mantegazzianum Sommier & Levier (Giant hogweed) has spread across Europe after its introduction as an ornamental from the native range in the Western Greater Caucasus. In addition to its ...invasive capability, H. mantegazzianum reduces the alpha diversity of native species in the non-native range and can cause second-degree burns when its phytotoxic sap contacts the skin upon exposure to sunlight. Previous studies on H. mantegazzianum distribution focused on individual countries, therefore we know little about the potential shift of the species distribution under changing climate at the continental scale. To fill that gap in the current knowledge, we aimed to (i) identify the most important climatic factors for the distribution of H. mantegazzianum in Europe, (ii) recognize areas that will be suitable and unsuitable for future climate scenarios to prioritize management action. Our study showed that the mean temperature of the coldest quarter (bio11) and temperature annual range (bio7) were the most important bioclimatic variables predicting the suitable habitat of the species in Europe. For all scenarios, we found that the majority of the range changes expected by 2100 will occur as early as 2041. We predicted an overall decrease in climatically suitable area for H. mantegazzianum under climate change with over three quarters (i.e. 94%) of the suitable area reduced under the Shared Socioeconomic Pathway (SSP) 585 in 2100. However, under the same scenario, climate conditions will likely favour the expansion (i.e. 20%) of H. mantegazzianum in northern Europe. The results from the present study will help in developing a climate change-integrated management strategy, most especially in northern Europe where range expansion is predicted.
Display omitted
•Invasive species are expected to shift their distributions due to climate change.•We used MaxEnt to predict range expansion and contraction of invasive giant hogweed.•Coldest quarter temperature was the most important constraint on its distribution.•Most of its current distribution will be lost under climate change in all scenarios.•Our results will help inform management actions for priority areas.
Questions
Due to the diverse abiotic conditions and the extensive, early‐autumn, manual mowing practiced once per few years, Molinia semi‐natural wet meadows are known for their high plant species ...diversity. However, recent socio‐economic transformations and land‐use changes (i.e. cessation of use) have been contributing to significant biodiversity loss in Molinia meadows. Thus, understanding the mechanisms of species co‐occurrence patterns operating on well‐developed Molinia meadows may be a precondition for the restoration or regeneration success of this type of vegetation. We aimed to identify community‐level co‐existence patterns of the whole set of plant species typical of Molinia meadows, and to assess the role of co‐occurring vegetation in shaping the performance of individual species.
Location
Natura 2000 Special Area of Conservation “Łąki Dąbrowskie” (S Poland).
Methods
Using generalised multiple regression techniques on a set of vegetation traits and components of functional diversity, we assessed the role of different ecological mechanisms in shaping co‐occurrence patterns of the entire group of species typical of Molinia meadows, as well as individual species belonging to this group.
Results
When the entire group of Molinia meadow species was taken into account, niche differentiation emerged as the main mechanism influencing the co‐occurrence of plant species. When considering individual species, we revealed that their co‐existence patterns were mostly species‐specific, pointing out the predominant role of either niche differentiation, competition, habitat filtering, or a combination of these three drivers in shaping assembly processes.
Conclusions
Our results showed that the variability of niches realised by target species typical of Molinia meadows was high. Therefore, conservation of well‐developed Molinia meadows should focus on both the community, and on a single species level, aiming to maintain a complex of specific microhabitat conditions. Considering small‐size patches of these meadows scattered in a transformed, agricultural landscape, conservation of individual target species should be of the highest priority.
High niche differentiation, identified to be the main mechanism determining the occurrence of the entire group of Molinia meadows species, may be considered as an indication of the high variability of niches realised by particular species. Examination of both the overall functional diversity of vegetation and the performance of single plant species is crucial to understand different community assembly drivers.
European ash (Fraxinus excelsior L.) dieback affects both overstory trees and natural regeneration. The decline of ash caused by severe crown defoliation and branch mortality has a high impact on ash ...natural regeneration. The site factors affecting the disease symptoms vary significantly and are not fully understood. Hence, we aimed to assess the joined effects of soil fertility and moisture (expressed by soil pH, CaCO3 content, and summer groundwater table level), herbivory, and health conditions connected with Hymenoscyphus fraxineus (T. Kowalski) Baral, Queloz, and Hosoya infestation on natural regeneration of F. excelsior. We examined 32 ash stands in Western Poland across soil fertility gradient. We established randomly selected circular plots (400 m2) in forests with ≥60% of ash in overstory species composition. We assessed natural regeneration density, the proportion of browsed trees, and trees damaged by ash dieback using generalized mixed-effects models. We found a higher proportion of damaged trees in neutral and base soils than in acid soils. Moreover, we found a low proportion of damaged trees in sites with low groundwater table levels. High CaCO3 content decreased the proportion of browsed trees, similarly as high shrub cover. The density of F. excelsior natural regeneration depended on groundwater table level, canopy cover, and proportion of damaged trees. We also found a positive relationship between density and deer browsing. The factor responsible for the higher infestation of saplings (low groundwater table level) also influenced natural regeneration density. This way, our study revealed how soil properties influence ash natural regeneration directly and indirectly. We showed that ash dieback will have a more severe impact on ash regeneration in ash typical sites. This is essential for predicting forest recovery and the ability to resilience after disturbances caused by H. fraxineus.
Joined effects of ash dieback, soil pH, and CaCO3 content, together with soil moisture, as well as deer browsing, affect ash regeneration.
Display omitted
•Patterns of ash dieback in ash natural regeneration are weakly understood.•We assessed ash natural regeneration density and health in ash-dominated forests.•Soil pH and moisture influence ash regeneration mortality.•Ash regeneration seems to be more vulnerable to ash dieback in ash typical sites.
Invasive tree species decrease ecosystem resilience with negative impacts on natural regeneration. The influence of alien tree species on ecosystems is unevenly recognized and does not always account ...for different habitat specificity. We assessed the impacts of the three most frequent invasive tree species in European forests: Prunus serotina Ehrh., Quercus rubra L., and Robinia pseudoacacia L. on natural regeneration diversity, species composition, and density. We hypothesized that invaded forest types, in comparison with non-invaded, will differ in terms of species composition, will have lower taxonomic, functional, and phylogenetic diversity of natural regeneration, and will have lower densities of native tree species. We used a set of 189 study plots (200 m2) in a systematic design, established in various forest types in Wielkopolski National Park (West Poland). We analyzed impacts of forest type, accounting for soil C:N ratio, soil pH, and light availability on natural regeneration (woody species up to 0.5 m height) species composition, diversity, and density. We found an overlap of species composition among invaded and non-invaded forests and low impacts of invasive species on taxonomic diversity and functional richness. We found no impacts on phylogenetic diversity and other functional diversity components. In contrast, we found that the natural regeneration of forest-forming tree species reached lower densities in invaded than non-invaded forest types. However, sub-canopy and shrub species reached higher densities in invaded than non-invaded forest types. We confirmed that invasive tree species affect natural regeneration by decreasing the regeneration density of native tree species (in eight of nine tree species studied), species composition homogenization, and supporting natural regeneration of sub-canopy and shrub species. Therefore, the restoration of invaded forests requires eradication of invasive tree species to decrease propagule pressure and to stop decreases in the abundance of native tree species’ natural regeneration.
PDF
