Table 4. Examples of Conservation management recommendations for three species to illustrate the patterns observed.
Genetic conservation management
Armeria maritima subsp. elongata
Risks and Essential Biodiversity Variables (EBVs) Discussion EBV value Conservation management recommendations
Sampling Connected gene flow is unlikely as the species is rare, distribution is scattered, and it has a poor dispersal ability; it occurs in similar but limited ecological conditions. Lower diversity / Higher differentiation High risk of sampling limited diversity. Genetic diversity within population is likely to be limited and/or differentiation among populations is high. In these situations, there is an increased impetus to sample from multiple populations to ensure the diversity is adequately sampled.
Donor selection Species reproduces sexually (obligatory cross) and has poor dispersal ability; distribution is scattered; ecological amplitude is limited and conditions are similar; no evidence of genetic incompatibilities found. Higher differentiation High risk of mixing. The degree of differentiation between populations is likely high and outbreeding depression is likely. Populations should not be mixed.
Genetic differentiation Species is rare, distribution is scattered, ecological amplitude is limited, and dispersal method is poor. Higher differentiation. Manage to increase genetic diversity. Populations have historically been isolated and have little contemporary gene flow; they are inbred, genetically divergent and are unlikely to be resilient to environmental change. Intensive and costly management (e.g., ongoing translocations) may be required to recover and sustain populations; invoke triage measures to assess whether the likelihood of recovery/persistence is sufficiently high to justify ongoing management expense. Investigate means to recover diversity in-situ (e.g., from soil seedbank); consider translocation if outbreeding depression risks can be managed.
Genetic diversity Species’ dispersal method is poor and recruitment is limited; distribution is rare and scattered; species has experienced a major decline. Lower diversity
Inbreeding potential Genetic diversity is expected to be low and distribution is scattered. High inbreeding potential
Silene latifolia
Essential Biodiversity Variables (EBVs) Discussion EBV value Conservation management recommendations
Sampling Connected gene flow is somewhat unlikely as although the species is not rare throughout much the British Isles and has an effective dispersal method, it has a patchy distribution in Wales, Eastern Scotland and Eastern Ireland. It also has a scattered distribution or is absent in West Scotland and Ireland. moderate-high diversity/ moderate differentiation Moderate risk of sampling limited diversity - populations are (likely to be) genetically differentiated and sampling should be geographically and/or environmentally stratified to encompass this variation. For some, only a few populations will exhibit divergence and minimal effort is required, for others, all/most populations may exhibit substantial differences and sampling from many will be required.
Donor selection Despite being long-lived with an effective dispersal method, the species is primarily outcrossing and occurs in divergent ecological conditions. It also has a propensity for hybridisation between intraspecific taxa, Silene latifolia subsp. alba (Mill.) Greuter & Burdet, and S. dioica which could make it more vulnerable to mixing. moderate differentiation Some risks associated with mixing - genetic differences that may lead to outbreeding depression have been predicted/documented and mixing is not recommended between divergent groups. However, mixing may be considered in the following situations 1) there is limited diversity among available donor populations (ex. contain </= 50-100 individuals) 2) there is a deliberate aim to mitigate effects of novel environmental conditions/changes by introducing genetic diversity from ecologically divergent populations 3) the risks are marginal (ex. population trait values only just exceed the illustrative conditions of low risk
Genetic differentiation The species reproduces sexually, with an effective dispersal method, is long-lived and is not rare in much of the British Isles. However, it occurs in a broad range of ecological conditions and has scattered and patchy distribution in Ireland, Scotland and Wales. low-moderate differentiation Manage populations to reduce breeding between genetically related individuals - populations have historically been connected and currently maintain gene flow, but there is risk of population declines due to inbreeding depression in the long term; local adaptation/outbreeding depression is likely to be minimal unless there are strong environmental gradients. Reduce breeding between genetically related individuals (e.g. facilitate pollen/seed immigration; conduct active translocations to increase population sizes and introduce new genetic diversity); manage pollinator/seed disperser populations where these have been perturbed; and continue to monitor outcomes.
Genetic diversity high diversity
Inbreeding potential Genetic is diversity is expected to be high and there is evidence of a scattered distribution. moderate- higher risk of inbreeding
Achillea millefolium
Essential Biodiversity Variables (EBVs) Discussion EBV value Conservation management recommendations
Sampling Connected gene flow is likely as the species is very common throughout the British Isles, has no evidence of fragmentation, populations occur in similar ecological conditions, and it has an effective dispersal method. Higher diversity / Lower differentiation Low risk of sampling limited diversity. The species exhibits (or is predicted to exhibit) little genetic structuring among populations and high diversity within them, hence most populations should be suitable. It is still advisable to obtain samples from large and genetically diverse populations from a range of sites across the distribution to maximise capture of genetic diversity.
Donor selection Although the species is outcrossing, connected gene flow is likely and its ecological conditions are similar Lower differentiation Low risk of mixing (unlikely to be detrimental, may be beneficial). Differentiation between populations is likely to be low, thus minimizing the chance of outbreeding depression. Genetic material from most populations can be used for restoration or mixed to increase diversity but it is advisable that plants from similar ecological conditions are used.
Genetic differentiation Species’ primary reproduction mode is sexual; it has an effective dispersal method, is long-lived, is very common throughout the British Isles with no evidence of fragmentation and has a limited ecological amplitude. Lower differentiation Based on evidence found, no management needed at this time. However, if management is to be considered, manage to maintain population sizes and gene flow. Populations have historically been connected, are genetically healthy, and currently maintain high levels of gene flow, potentially acting as metapopulations; translocations between populations is a viable option to boos population sizes; local adaptation/outbreeding depression is likely to be minimal unless there are stronger environmental gradients. Manage species-level ecological and demographic threats to maintain population sizes and gene flow (e.g., corridors); and maintain/facilitate metapopulation dynamics.
Genetic diversity Higher diversity
Inbreeding potential Genetic diversity is likely to be high, population size is >100 individuals, and there is no evidence of fragmentation. Low inbreeding potential