Comparative patterns of plant invasions in the mediterranean biome

The objective of this work was to compare and contrast the patterns of alien plant invasions in the world’s five mediterranean-climate regions (MCRs). We expected landscape age and disturbance history to have bearing on levels of invasion. We assembled a database on naturalized alien plant taxa occurring in natural and semi-natural terrestrial habitats of all five regions (specifically Spain, Italy, Greece and Cyprus from the Mediterranean Basin, California, central Chile, the Cape Region of South Africa and Southwestern - SW Australia). We used multivariate (hierarchical clustering and NMDS ordination) trait and habitat analysis to compare characteristics of regions, taxa and habitats across the mediterranean biome. Our database included 1627 naturalized species with an overall low taxonomic similarity among the five MCRs. Herbaceous perennials were the most frequent taxa, with SW Australia exhibiting both the highest numbers of naturalized species and the highest taxonomic similarity (homogenization) among habitats, and the Mediterranean Basin the lowest. Low stress and highly disturbed habitats had the highest frequency of invasion and homogenization in all regions, and high natural stress habitats the lowest, while taxonomic similarity was higher among different habitats in each region than among regions. Our analysis is the first to describe patterns of species characteristics and habitat vulnerability for a single biome. We have shown that a broad niche (i.e. more than one habitat) is typical of naturalized plant species, regardless of their geographical area of origin, leading to potential for high homogenization within each region. Habitats of the Mediterranean Basin are apparently the most resistant to plant invasion, possibly because their landscapes are generally of relatively recent origin, but with a more gradual exposure to human intervention over a longer period

Horizon scanning for invasive alien species with the potential to threaten biodiversity and human health on a Mediterranean island

© 2019, The Author(s). Invasive alien species (IAS) are one of the major drivers of change that can negatively affect biodiversity, ecosystem functions and services and human health; islands are particularly vulnerable to biological invasions. Horizon scanning can lead to prioritisation of IAS to inform decision-making and action; its scale and scope can vary depending on the need. We focussed on IAS likely to arrive, establish and affect biodiversity and human health on the Mediterranean island of Cyprus. The scope of the horizon scanning was the entire island of Cyprus. We used a two-step consensus-building process in which experts reviewed and scored lists of alien species on their likelihood of arrival, establishment and potential to affect biodiversity, ecosystems and/or human health in the next 10 years. We reviewed 225 alien species, considered to be currently absent on Cyprus, across taxa and environments. We agreed upon 100 species that constituted very high, high or medium biodiversity risk, often arriving through multiple pathways of introduction. The remaining 125 species were ranked as low risk. The potential impacts on human health were documented for all 225 species; 82 species were considered to have a potentially negative impact on human health ranging from nuisance to disease transmission. The scope of the horizon scanning was the entire island of Cyprus, but the thematic groups also considered the relevance of the top 100 species to the Sovereign Base Areas of Cyprus, given their differing governance. This horizon scan provides the first systematic exercise to identify invasive alien species of potential concern to biodiversity and ecosystems but also human health within the Mediterranean region. The process and outcomes should provide other islands in the region and beyond with baseline data to improve IAS prioritisation and management

The peatland map of Europe

Based on the ‘European Mires Book’ of the International Mire Conservation Group (IMCG), this article provides a composite map of national datasets as the first comprehensive peatland map for the whole of Europe. We also present estimates of the extent of peatlands and mires in each European country individually and for the entire continent. A minimum peat thickness criterion has not been strictly applied, to allow for (often historically determined) country-specific definitions. Our ‘peatland’ concept includes all ‘mires’, which are peatlands where peat is being formed. The map was constructed by merging national datasets in GIS while maintaining the mapping scales of the original input data. This ‘bottom-up’ approach indicates that the overall area of peatland in Europe is 593,727 km². Mires were found to cover more than 320,000 km² (around 54 % of the total peatland area). If shallow-peat lands (< 30 cm peat) in European Russia are also taken into account, the total peatland area in Europe is more than 1,000,000 km2, which is almost 10 % of the total surface area. Composite inventories of national peatland information, as presented here for Europe, may serve to identify gaps and priority areas for field survey, and help to cross-check and calibrate remote sensing based mapping approaches

Photoinhibition of seed germination in the maritime plant matthiola tricuspidata

The three-horned stock, Matthiola tricuspidata (L.) R. Br. Is a widespread annual plant of the Mediterranean sandy shores. Its seeds are dark germinating and negatively photosensitive, in accordance with our previous findings for a number of other maritime plants. Full germination was obtained at a wide range of temperatures (5-25 °C) in the dark. Inhibition of germination under light of various spectral qualities could be generally correlated, negatively and positively, respectively, with phytochrome photostationary state (ϟ) and relative cycling rate of phytochrome (H). The inhibition of germination by white (fluorescent), blue and far-red light, applied either continuously or intermittently, consistently showed a linear dependence upon the logarithm of the flux density of the irradiation. The resulting photoinhibition curves had parallel slopes and, compared to those of other maritime plants, they were shifted to higher flux densities, Continuous blue or far-red irradiations, both establishing a similar ϟ value (0η26), resulted in statistically similar regression curves, thus favouring the hypothesis that phytochrome is the single photoreceptor in the photoinhibition of seed germination. © 1994 Academic Press

The alien flora of Greece: Taxonomy, life traits and habitat preferences

The aim of the paper is the state-of-the-art assessment of the alien flora of Greece and its traits. The dataset consists of a total of 343 alien taxa, including 49 archaeophytes. The taxonomy, life traits and habitat of the 294 neophytes are analysed vs their naturalisation status. Out of the 122 (41%) naturalised neophytes, 50 are identified as exhibiting invasive behaviour. Poaceae, Asteraceae, Amaranthaceae, Solanaceae, Fabaceae, and Polygonaceae are the plant families richest in alien taxa. The majority of them are of American origin, followed by those of Asiatic and Mediterranean origin. The neophytes are predominantly herbs, most of them annuals. Yet, the perennial life cycle is equally frequent with the annual one and the proportion of phanerophytes in the alien flora is increased compared to the one of the native flora. Regarding flowering traits, most of the aliens have a long flowering period (over 1 month) and flower in late spring, summer and autumn, when few of the native plants are in bloom. Vertebrate zoochory and anemochory are the two dispersal modes mostly utilised by the alien plants (43 and 28%, respectively), while more than one dispersal mechanisms are functional for 56% of them. Artificial habitats have the highest frequencies of alien plants. The natural habitats with the highest numbers of aliens are the coastal ones and inland surface waters. Opuntia ficus-barbarica, Ailanthus altissima, Oxalis pes-caprae, Erigeron bonariensis, Amaranthus albus and Symphyotrichum squamatum are typical cases of plants characterised as invasive, having established in almost all the habitat groups identified. The diversity of the ecological characteristics of the plants suggests a potential of impacts that needs to be further assessed. © 2010 Springer Science+Business Media B.V

Conservation biology of Chionodoxa lochiae and Scilla morrisii (Asparagaceae): Two priority bulbous plant species of the European Union in Cyprus

This paper presents data regarding conservation biology of Chionodoxa lochiae and Scilla morrisii; two threatened endemic plants of Cyprus, which are included as priority species in Annex II of the Habitats Directive. The population size and geographical distribution of the species were monitored for three years. C. lochiae was recorded in ten locations and S. morrisii was recorded in five locations. C. lochiae occurs in Pinus forests with/without Quercus alnifolia understory or in forest margins and riparian vegetation with Platanus orientalis. Favorable habitat of S. morrisii is the understory of Quercus infectoria stands and the Pistacia terebinthus-Quercus coccifera-Styrax officinalis shrubs. The distribution pattern of the species seems to follow habitat availability. Fecundity and Relative Reproductive Success of C. lochiae were stable and low, while in S. morrisii were constantly high. The lack of pollinators seems to be the main cause of the low sexual reproduction of C. lochiae. The germination strategy for both species is dependent on temperature. Some of the seeds are dormant and dormancy is broken by nitrates. The investigation of certain aspects of the biology of the two species yielded the information needed to identify the critical aspects affecting their survival and to propose sound conservation measures. © 2015 The Authors

Biogeographical determinants for total and endemic species richness in a continental archipelago

We examined the relationship between plant species richness and biogeographical variables (island area, island maximum elevation, distance from nearest inhabited island, distance from nearest mainland) using a data set comprising 201 islands of the Aegean archipelago. We found that endemic species richness was strongly correlated to total species richness. Single-island endemic species richness was most strongly correlated to island maximum elevation, and then to island area, with an apparent small island effect for islands smaller than 47 km2. Total species richness was most strongly correlated to island area (with no apparent small island effect), and less strongly correlated to island maximum elevation. Distance from the mainland or other inhabited islands displayed limited predictive value in our data set. The slope of the relationship between species richness and geographical factors (island area, elevation, distance from island/mainland) was steeper for endemic species richness than for total richness. Finally, the different scales of endemicity (single-island endemics, island group endemics and Aegean regional endemics) displayed similar qualitative trends and only differed quantitatively. Thus, we conclude that different biogeographical factors act as drivers for total species richness than for endemic species richness. © Springer Science+Business Media B.V. 2009

An integrated approach for the conservation of threatened plants: The case of Arabis kennedyae (Brassicaceae)

The aim of this paper is to propose an integrated approach (including population and habitat monitoring and the study of reproductive biology and genetic diversity) for the comprehensive study of threatened plants, for which conservation measures are imperative. We applied this model to the plant species Arabis kennedyae which is classified as endangered according to the IUCN criteria. The current population of the species consists of three small subpopulations (AR1, AR2, and AR3) at three locations. Population size was characterized by considerable annual fluctuations. The distribution pattern of the plant followed habitat availability. Relative Reproductive Success remained stable but moderate. Germination of dormant seeds was promoted by light and was optimal at 15 and 20 °C. Genetic analysis showed low interpopulation variability and detected two groups: haplotype I (AR1 and AR3) and haplotype II (AR2), which may represent two altitudinal ecotypes. The direct threats identified were related to recreation activities, road construction and fire. The subpopulations of the plant are regulated by density and depend on fecundity and on the soil seedbank while their persistence depends mainly on habitat availability. Low genetic diversity combined with small population size and a possible reduction in fitness suggest increased susceptibility to loss of genetic variation. The overall results suggest that ex situ conservation in a seed bank, and in situ conservation in the form of population restoration, are suitable conservation measures and the study of the different aspects of the species&apos; biology has provided the data required for their implementation. © 2011 Elsevier Masson SAS