Exploring vulnerability of listed Mediterranean plants in relation to risks of population loss

Abstract

In this paper, we propose a method to assess population numbers and quantify their vulnerability for listed plant species. For six study species, the spatial aggregation of point data allowed us to identify the numbers of populations for each species and thus how they differ in regional abundance. We assessed vulnerability by according a score to each population in relation to three criteria: (i) land-use (urbanisation, agriculture and natural areas), (ii) fragmentation of populations by infrastructures and (iii) protected status of populations. As a result of the combination and scoring of populations across the three criteria, only 9% have a low extinction risk and 73% are in one of the three classes of high vulnerability with 16% in the highest category. Finally, 29 of 32 populations monitored in a separate study are in one of the three highest categories of vulnerability. This study illustrates how information on population numbers of listed species at the regional scale brings to the fore their generalised vulnerability to threats in the Mediterranean landscape. This information is vital for conservation management staff to develop a strategy and appropriate actions for listed species' protection.

Niche Variation in Endemic Lilium pomponium on a Wide Altitudinal Gradient in the Maritime Alps

“…Such work could identify sites that may require management in terms of forest closure and localised disturbance. In addition, at the regional scale, it will be useful to evaluate the status of populations at the landscape scale, using a threat criteria that assesses the relative percentage of natural habitats or urbanisation, the fragmentation of populations, and the area of a population in a protected area, as conducted for several other species in the South of France [ 44 ].…”

Assessing vulnerability of listed Mediterranean plants based on population monitoring

“…A large proportion of their populations ( Fig. 1) occur in areas that have undergone rapid urbanisation and land-development for infrastructures and commercial enterprises in the last 50 years and the indirect factors that may influence population vulnerability are assessed in a separate paper (Gauthier, Bernard, & Thompson, 2019). The populations were chosen to represent a gradient of situations from populations where direct impacts were foreseeable during the nine years of our study (some were known to have part of their populations in a development programme) to secluded and low-risk zones.…”

“…Although all species are listed for protection, the viability of their populations is compromised by human impacts. In a subsequent study (Gauthier et al, 2019) this vulnerability is analysed at the scale of their surrounding landscape and risk of further impacts.…”

Is a restricted niche the explanation for species vulnerability? Insights from a large field survey of Astragalus tragacantha L. (Fabaceae)

“…Land use changes in relation to human activities constitute now a major threat for this rare biodiversity adapted to harsh stressful habitats (Mendoza-Fernández et al, 2014). Even when they are red listed, direct disturbance caused by human activities may compromise the persistence of rare species (Gauthier et al, 2019). Such a scenario is a perfect illustration of the situation of rare plants in coastal Provence (South East France).…”