Ecological and genetic basis of metapopulation persistence of the Glanville fritillary butterfly in fragmented landscapes

Abstract

Ecologists are challenged to construct models of the biological consequences of habitat loss and fragmentation. Here, we use a metapopulation model to predict the distribution of the Glanville fritillary butterfly during 22 years across a large heterogeneous landscape with 4,415 small dry meadows. The majority (74%) of the 125 networks into which the meadows were clustered are below the extinction threshold for long-term persistence. Among the 33 networks above the threshold, spatial configuration and habitat quality rather than the pooled habitat area predict metapopulation size and persistence, but additionally allelic variation in a SNP in the gene Phosphoglucose isomerase (Pgi) explains 30% of variation in metapopulation size. The Pgi genotypes are associated with dispersal rate and hence with colonizations and extinctions. Associations between Pgi genotypes, population turnover and metapopulation size reflect eco-evolutionary dynamics, which may be a common feature in species inhabiting patch networks with unstable local dynamics.

Genetics of dispersal

“…A recent exception is Hanski et al . (), who used a metapopulation model to predict the distribution of the Glanville fritillary butterfly over 22 years across the heterogeneous landscape of the Åland islands SW Finland. Of the 125 population networks 33 were above the extinction threshold for long‐term persistence.…”

The relative importance of local and regional processes to metapopulation dynamics

“…Each fall all of the potential habitat patches are surveyed for the presence of these larval nests (see Ojanen et al, for details of the survey). Based on control surveys, it has been estimated that the presence of the butterfly is not detected in up to 15% of occupied patches with non‐detection mainly occurring in very small populations (Hanski et al, ). Based on the long‐term data, we know that all local populations are more or less ephemeral, due to being very small and commonly having just a single or a few larval groups in a given year (Hanski, , ).…”

“…We examine the sensitivity of the resulting dispersal network structure in the Supporting Information, finding no appreciable difference in patch connectivity estimates (see Figure S1). Patch area may influence dispersal probability and subsequent links between habitat patches in the network (Hanski, ; Hanski et al, ). We incorporated the influence of patch area on the structure of the dispersal network by modifying the negative exponential dispersal kernel, where links between two habitat patches were defined as a function of the area of both patches ( A i and A j ), both of which were raised to constants obtained from previous studies (Hanski et al, ), which represent the relationships between patch area and immigration ( im = 0.3) and emigration ( em = 0.3) rates (see Equation 1).…”

Achteruitgang insectenpopulaties in Nederland: trends, oorzaken en kennislacunes

“…Dit omdat de verhoogde nutriëntengehaltes ervoor zorgen dat aquatische ecosystemen van een heldere, door waterplanten gedomineerde situatie omslaan naar een troebele door algen gedomineerde situatie waarin een andere, soortenarmere insectengemeenschap voorkomt (Scheffer 1998). Zo correleerde de fosfaatbelasting van verschillende Nederlandse waterlichamen met aquatische levensgemeenschappen waarbij minder soorten met een diapause/winterrust of popstadium voorkwamen en meer soorten met een parasitaire levenswijze aanwezig waren dan in gemeenschappen waar de fosfaatbelasting lager was (Ieromina, Musters et al 2016 (Hanski, 1998;Ovaskainen and Hanski, 2003;Hanski, Schulz et al 2017). In het algemeen geldt dat insectensoorten met een lange levensduur en een geringe dispersiecapaciteit gevoeliger zijn voor de negatieve effecten van versnippering (Vermeulen, 1995;Hanski, 1998;Wallis de Vries, 2014;Van Noordwijk, Verberk et al 2015;Rossetti, Tscharntke et al 2017).…”