Applications In Conservation Biology Research Articles

A validated LC–MS/MS method for simultaneous determination of key glucocorticoids in animal hair for applications in conservation biology

A new method for the determination of main glucocorticoids (cortisol, cortisone, and corticosterone) in hair by liquid chromatography-tandem mass spectrometry was developed. Glucocorticoids were extracted from hair shafts using methanol followed by solid-phase extraction. A validation test was performed using hair from three species of wild mammals with different body size (0.2–800 kg), lifestyle (terrestrial, burrowing and arboreal species), social organization (living in herds or solitary), and different predicted type of hair glucocorticoids: European bison (Bison bonasus), European hamster (Cricetus cricetus), and Eurasian red squirrel (Sciurus vulgaris). Regardless of the species evaluated, the method shows good linearity for all analytes accompanied by satisfactory accuracy (91–114%) and precision (RSD < 13%). Depending on the analyte and hair origin, the calculated limits of quantification were between 0.05 and 1.19 ng/mL, which corresponds to 1.28–31.51 pg/mg. Using cortisol and cortisone as examples, we have demonstrated that measuring multiple glucocorticoids simultaneously provides more comprehensive information than solely concentrating on one, thereby contributing to a more balanced and reliable interpretation of the acquired results. However, the utility of cortisol metabolites as markers of stress response in keratinized tissues should be substantiated by additional experimental studies on targeted animals. We posit that this paper could serve as a crucial catalyst to prompt such experiments.

Assessing chronic stress in wild mammals using claw-derived cortisol: a validation using European badgers (Meles meles).

Measuring stress experienced by wild mammals is increasingly important in the context of human-induced rapid environmental change and initiatives to mitigate human-wildlife conflicts. Glucocorticoids (GC), such as cortisol, mediate responses by promoting physiological adjustments during environmental perturbations. Measuring cortisol is a popular technique; however, this often reveals only recent short-term stress such as that incurred by restraining the animal to sample blood, corrupting the veracity of this approach. Here we present a protocol using claw cortisol, compared with hair cortisol, as a long-term stress bio-indicator, which circumvents this constraint, where claw tissue archives the individual's GC concentration over preceding weeks. We then correlate our findings against detailed knowledge of European badger life history stressors. Based on a solid-phase extraction method, we assessed how claw cortisol concentrations related to season and badger sex, age and body-condition using a combination of generalized linear mixed models (GLMM) (n= 668 samples from 273 unique individuals) followed by finer scale mixed models for repeated measures (MMRM) (n= 152 re-captured individuals). Claw and hair cortisol assays achieved high accuracy, precision and repeatability, with similar sensitivity. The top GLMM model for claw cortisol included age, sex, season and the sex*season interaction. Overall, claw cortisol levels were significantly higher among males than females, but strongly influenced by season, where females had higher levels than males in autumn. The top fine scale MMRM model included sex, age and body condition, with claw cortisol significantly higher in males, older and thinner individuals. Hair cortisol was more variable than claw; nevertheless, there was a positive correlation after removing 34 outliers. We discuss strong support for these stress-related claw cortisol patterns from previous studies of badger biology. Given the potential of this technique, we conclude that it has broad application in conservation biology.

The power of metabarcoding: Can we improve bioassessment and biodiversity surveys of stream macroinvertebrate communities?

Most stream bioassessment and biodiversity surveys are currently based on morphological identification of communities. However, DNA metabarcoding is emerging as a fast and cost-effective alternative for species identification. We compared both methods in a survey of benthic macroinvertebrate communities across 36 stream sites in northern Finland. We identified 291 taxa of which 62% were identified only by DNA metabarcoding. DNA metabarcoding produced extensive species level inventories for groups (Oligochaeta, Chironomidae, Simuliidae, Limoniidae and Limnephilidae), for which morphological identification was not feasible due to the high level of expertise needed. Metabarcoding also provided more insightful taxonomic information on the occurrence of three red-listed vulnerable or data deficient species, the discovery of two likely cryptic and potentially new species to Finland and species information of insect genera at an early larval stage that could not be separated morphologically. However, it systematically failed to reliably detect the occurrence of gastropods that were easily identified morphologically. The impact of mining on community structure could only be shown using DNA metabarcoding data which suggests that the finer taxonomic detail can improve detection of subtle impacts. Both methods generally exhibited similar strength of community-environment relationships, but DNA metabarcoding showed better performance with presence/absence data than with relative DNA sequence abundances. Our results suggest that DNA metabarcoding holds a promise for future anthropogenic impact assessments, although, in our case, the performance did not improve much from the morphological species identification. The key advantage of DNA metabarcoding lies in efficient biodiversity surveys, taxonomical studies and applications in conservation biology.

Assessing the impact of climate change on the distribution of Osmanthus fragrans using Maxent.

Models that evaluate the potential geographic distribution of species can be used with a variety of important applications in conservation biology. Osmanthus fragrans has high ornamental, culinary, and medicinal value, and is widely used in landscaping. However, its preferred habitat and the environmental factors that determine its distribution remain largely unknown; the environmental factors that shape its suitability also require analysis. Based on 89 occurrence records and 30 environmental variables, this study constructed Maxent models for current as well as future appropriate habitats for O. fragrans. The results indicate that UV-B seasonality (19.1%), precipitation seasonality (18.8%), annual temperature range (13.1%), and mean diurnal temperature range (12.5%) were the most important factors used for interpreting the environmental demands for this species. Highly appropriate habitats for O. fragrans were mainly distributed in southwestern Jiangsu, southern Anhui, Shanghai, Zhejiang, Fujian, northern Guangdong, Guangxi, southern Hunan, southern Hubei, Sichuan, and Taiwan. Under climate change scenarios, the spatial extent of the area of suitable distribution will decrease, and the distribution center of O. fragrans will shift to the southwest. The results of this study will help land managers to avoid blindly introducing this species into inappropriate habitat while improving O. fragrans yield and quality.

Genetic and environmental factors in the trade‐off between sexual and asexual reproduction of a rare clonal angiosperm

AbstractUnderstanding the factors that influence the trade‐off between flowering and clonal growth in angiosperms is of great interest to botanists, plant ecologists and evolutionary biologists. Being able, ultimately, to manipulate these factors has potentially wide‐ranging applications in conservation biology, horticulture and agriculture. A rare, native Australian species, Melaleuca deanei, displays a low frequency of flowering and failed seedling recruitment, with persistence and expansion in the field predominantly via clonal root suckering. A decade of studies into its reproductive biology and ecology reveal both genetic and environmental factors reducing sexual success within its populations. Five factors influencing the trade‐off from sexual reproduction to clonal propagation are distilled and discussed in this work: 1. environmental constraint on sexual success; 2. small population size/low mate availability; 3. an obligate outcrossing breeding system; 4. somatic mutations in older clones; and 5. phylogenetic constraint. The work is potentially informative to the life cycles and management of other clonal angiosperms, be they rare and endangered; highly fecund weedy species; or economically important species. Methods to test each factor in future studies are proposed.

Ecological modeling and distribution analysis of digger scorpions: Odontobuthus doriae, Odonthubutus bidentatus (Scorpiones: Buthidae) and Scorpio maurus (Scorpiones: Scorpionidae) in Iran using the maximum entropy method

Prediction models are essential for the potential geographic distribution of scorpions, prevention of scorpion stings and diverse applications in conservation biology. There is limited information about habitat suitability and the factors affecting the distribution of Iranian digger scorpions. This study was undertaken to model the distribution of three types of digger scorpion in Iran, Odontobuthus doriae Thorell, Odonthubutus bidentatus Lourenco (Scorpiones: Buthidae) and Scorpio maurus Pocockin (Scorpiones: Scorpionidae), and investigate the factors affecting its distribution using the maximum entropy method. A total of 20 environmental and climate variables were used for modeling and evaluation of the ecological niche. The similarities and differences between the ecological overlap of the digger scorpions were evaluated using comparative environmental niche model (ENM Tools software). The results showed that the main factors for habitat suitability of O. doriae were soil type, mean temperature of the wettest quarter and slope. The variables for S. maurus were soil type, precipitation of the coldest quarter and slope. Annual temperature range, mean temperature of the driest quarter and land use had the greatest influence on the distribution of O. bidentatus. The ecological niches for O. doriae and O. bidentatus overlapped. The niche of these species differed from the niche of S. maurus. This approach could be helpful for the prediction of the potential distribution of three digger scorpion species and this model can be an effective for the promotion of health.

Initial growth of northern fur seal (Callorhinus ursinus) colonies at the South Farallon, San Miguel, and Bogoslof Islands

Understanding the colonization or recolonization of breeding sites used by colonial animals is fundamental to metapopulation theory and has practical applications in conservation biology. Historically, pinniped species were heavily exploited worldwide, resulting in some breeding colonies becoming extirpated. As populations recover, some abandoned sites may be recolonized or new sites can be colonized. We analyzed aerial and ground survey data on pup counts from 3 islands (South Farallon, San Miguel, and Bogoslof) (re)colonized by northern fur seals (Callorhinus ursinus), using classical and Bayesian state-space modeling approaches to describe population growth rates during their initial 21 years, with particular focus on the South Farallon Islands. We used information from tagged animals that immigrated to the South Farallon Islands from San Miguel Island to describe the age and sex structure of the founding recolonizers of the South Farallon Islands. We also examined the evidence for the generality of Roux's (1987) description of fur seal population recovery using a literature review of published fur seal population growth rates. We found the 3 colonies had different annual population growth rates (South Farallon = 34%, San Miguel = 45%, Bogoslof = 59%), but all were growing at rates among the fastest observed for fur seals worldwide. Immigrants from San Miguel to the South Farallon Islands were younger and femalebiased relative to the tagged population at San Miguel Island. The general framework described by Roux (1987) was an effective description of observed fur seal population recovery. Our results inform our understanding of the initiation and growth of pinniped breeding colonies.

Whole-genome sequencing approaches for conservation biology: Advantages, limitations and practical recommendations.

Whole-genome resequencing (WGR) is a powerful method for addressing fundamental evolutionary biology questions that have not been fully resolved using traditional methods. WGR includes four approaches: the sequencing of individuals to a high depth of coverage with either unresolved or resolved haplotypes, the sequencing of population genomes to a high depth by mixing equimolar amounts of unlabelled-individual DNA (Pool-seq) and the sequencing of multiple individuals from a population to a low depth (lcWGR). These techniques require the availability of a reference genome. This, along with the still high cost of shotgun sequencing and the large demand for computing resources and storage, has limited their implementation in nonmodel species with scarce genomic resources and in fields such as conservation biology. Our goal here is to describe the various WGR methods, their pros and cons and potential applications in conservation biology. WGR offers an unprecedented marker density and surveys a wide diversity of genetic variations not limited to single nucleotide polymorphisms (e.g., structural variants and mutations in regulatory elements), increasing their power for the detection of signatures of selection and local adaptation as well as for the identification of the genetic basis of phenotypic traits and diseases. Currently, though, no single WGR approach fulfils all requirements of conservation genetics, and each method has its own limitations and sources of potential bias. We discuss proposed ways to minimize such biases. We envision a not distant future where the analysis of whole genomes becomes a routine task in many nonmodel species and fields including conservation biology.

How Elephant Seals (Mirounga leonina) Adjust Their Fine Scale Horizontal Movement and Diving Behaviour in Relation to Prey Encounter Rate.

Understanding the diving behaviour of diving predators in relation to concomitant prey distribution could have major practical applications in conservation biology by allowing the assessment of how changes in fine scale prey distribution impact foraging efficiency and ultimately population dynamics. The southern elephant seal (Mirounga leonina, hereafter SES), the largest phocid, is a major predator of the southern ocean feeding on myctophids and cephalopods. Because of its large size it can carry bio-loggers with minimal disturbance. Moreover, it has great diving abilities and a wide foraging habitat. Thus, the SES is a well suited model species to study predator diving behaviour and the distribution of ecologically important prey species in the Southern Ocean. In this study, we examined how SESs adjust their diving behaviour and horizontal movements in response to fine scale prey encounter densities using high resolution accelerometers, magnetometers, pressure sensors and GPS loggers. When high prey encounter rates were encountered, animals responded by (1) diving and returning to the surface with steeper angles, reducing the duration of transit dive phases (thus improving dive efficiency), and (2) exhibiting more horizontally and vertically sinuous bottom phases. In these cases, the distance travelled horizontally at the surface was reduced. This behaviour is likely to counteract horizontal displacement from water currents, as they try to remain within favourable prey patches. The prey encounter rate at the bottom of dives decreased with increasing diving depth, suggesting a combined effect of decreased accessibility and prey density with increasing depth. Prey encounter rate also decreased when the bottom phases of dives were spread across larger vertical extents of the water column. This result suggests that the vertical aggregation of prey can regulate prey density, and as a consequence impact the foraging success of SESs. To our knowledge, this is one of only a handful of studies showing how the vertical distributions and structure of prey fields influence the prey encounter rates of a diving predator.

Effective sizes and time to migration–drift equilibrium in geographically subdivided populations

Many versions of the effective population size (Ne) exist, and they are important in population genetics in order to quantify rates of change of various characteristics, such as inbreeding, heterozygosity, or allele frequencies. Traditionally, Ne was defined for single, isolated populations, but we have recently presented a mathematical framework for subdivided populations. In this paper we focus on diploid populations with geographic subdivision, and present new theoretical results. We compare the haploid and diploid versions of the inbreeding effective size (NeI) with novel expression for the variance effective size (NeV), and conclude that for local populations NeV is often much smaller than both versions of NeI, whenever they exist. Global NeV of the metapopulation, on the other hand, is close to the haploid NeI and much larger than the diploid NeI. We introduce a new effective size, the additive genetic variance effective size NeAV, which is of particular interest for long term protection of species. It quantifies the rate at which additive genetic variance is lost and we show that this effective size is closely related to the haploid version of NeI. Finally, we introduce a new measure of a population’s deviation from migration–drift equilibrium, and apply it to quantify the time it takes to reach this equilibrium. Our findings are of importance for understanding the concept of effective population size in substructured populations and many of the results have applications in conservation biology.

Value of information and monitoring in conservation biology

In this paper we consider uses of value of information studies in conservation biology. It is a common assumption that more and better quality data will lead to better conservation management decisions. Indeed, this assumption lies behind, and motivates, a great deal of current work in conservation biology. Of course, more data can lead to better decisions in some cases but decision-theoretic models of the value of information show that this need not always be the case: sometimes the cost of data collection is too high. While such value of information studies are well known in economics and decision theory circles, their applications in conservation biology are relatively new. These studies are a valuable tool for conservation management, and we outline some of the potential applications. We also offer some advice about, and problems with, implementing value of information studies in conservation settings.

Characterization of newly developed expressed sequence tag-derived microsatellite markers revealed low genetic diversity within and low connectivity between European Saccharina latissima populations

The kelp Saccharina latissima is a species of high ecological and economic importance. We developed a novel set of S. latissima-specific genetic markers that will find applications in conservation biology, biodiversity assessment, and commercial exploitation of this macroalga. Thirty-two expressed sequence tag (EST)-derived microsatellite markers (SSRs) were developed and characterized in this study using publically available EST sequences. Twenty-seven percent of the 7064 analyzed ESTs contained repeat motifs, and polymerase chain reaction (PCR) amplification primers were designed for 96 selected loci. Fifty-one (53 %) of the primer pairs amplified their target loci, of which 32 (33 %) were polymorphic within a sample of 96 S. latissima sporophytes collected from six localities distributed along the European Atlantic coast from Southern Brittany (France) to Spitzbergen (Norway). The 32 loci harbored moderate levels of polymorphism with 2–13 alleles per locus (mean 5.4). The 25 loci that were retained for population genetic analyses revealed substantial genetic differentiation among the European populations (pairwise F ST values ranging from 0.077 to 0.562) that did not follow any pattern of isolation by distance. In addition, within-population genetic diversity was generally low (Hs < 0.323). Two non-mutually exclusive hypotheses were proposed to explain this low diversity pattern: (1) lower variability of the EST-derived microsatellites compared to the random distribution of SSRs developed from genomic DNA since the former are frequently located in coding regions, which are generally less variable, or (2) reduced effective population size of S. latissima. The particularly high genetic differentiation between the French and Scandinavian S. latissima populations is in agreement with the reported ecotypic differentiation, which may reflect an important resource for genetic improvement. The pattern of genetic diversity revealed in this study thus suggests that care should be taken to avoid the transfer of strains between different geographic regions.

Pairwise measures of species co-occurrence for choosing indicator species and quantifying overlap

One of the most important ecological relationships between any two species is the degree of overlap in their distributions, i.e., their co-occurrence. Quantifying this relationship is a key step in the selection of indicator species and many other analyses in conservation biology and ecology. We derived a measure of the co-occurrence of two species based on the relative mutual information (RMI) of their distributions, and then compared its performance to three existing statistics: bivariate or binary covariance (BC), mean pairwise index (MPI), and proportional similarity (PS). To make this comparison, we measured co-occurrence values for all pairwise combinations of species collected from three communities (ground-dwelling beetles, moths, and vascular plants) in the Jerusalem Mountains and Judean Foothills, central Israel. We then used these co-occurrence values to address two different ecological problems: the challenge of identifying good indicator species, and the question of whether congeneric species co-occur more than species from different genera. We found that PS and RMI were the most reliable basis for choosing indicator species, but these two statistics differed in their error structures: PS had lower rates of type I errors (false positives), while RMI had lower rates of type II errors (false negatives). We also found that congeneric species co-occurred more often than species from different genera, but this pattern was statistically significant for only some of the measures of co-occurrence. In our analysis, then, the conclusion that we reached regarding the co-occurrence of congeneric species depended on which co-occurrence statistic was used. We therefore caution that available co-occurrence statistics should not be used interchangeably, because the ecological inferences drawn from a study may depend on the choice of co-occurrence statistic. In summary, we recommend PS and RMI as pairwise measures of species co-occurrence for investigating the reliability of biodiversity indicators and other applications in conservation biology and ecology.

Dynamics of a predator-prey system with prey subject to Allee effects and disease

In this article, we propose a general predator-prey system where prey is subject to Allee effects and disease with the following unique features: (i) Allee effects built in the reproduction process of prey where infected prey (I-class) has no contribution; (ii) Consuming infected prey would contribute less or negatively to the growth rate of predator (P-class) in comparison to the consumption of susceptible prey (S-class). We provide basic dynamical properties for this general model and perform the detailed analysis on a concrete model (SIP-Allee Model) as well as its corresponding model in the absence of Allee effects (SIP-no-Allee Model); we obtain the complete dynamics of both models: (a) SIP-Allee Model may have only one attractor (extinction of all species), two attractors (bi-stability either induced by small values of reproduction number of both disease and predator or induced by competition exclusion), or three attractors (tri-stability); (b) SIP-no-Allee Model may have either one attractor (only S-class survives or the persistence of S and I-class or the persistence of S and P-class) or two attractors (bi-stability with the persistence of S and I-class or the persistence of S and P-class). One of the most interesting findings is that neither models can support the coexistence of all three S, I, P-class. This is caused by the assumption (ii), whose biological implications are that I and P-class are at exploitative competition for S-class whereas I-class cannot be superior and P-class cannot gain significantly from its consumption of I-class. In addition, the comparison study between the dynamics of SIP-Allee Model and SIP-no-Allee Model lead to the following conclusions: 1) In the presence of Allee effects, species are prone to extinction and initial condition plays an important role on the surviving of prey as well as its corresponding predator; 2) In the presence of Allee effects, disease may be able to save prey from the predation-driven extinction and leads to the coexistence of S and I-class while predator can not save the disease-driven extinction. All these findings may have potential applications in conservation biology.

Predicting minimum area requirements of butterflies using life-history traits

The minimum area requirement (MAR) of a species is the amount of functional habitat necessary for population persistence. The accurate measurement of MAR in the field usually requires long and precise investigations of all resources used by the target organism. Here we tested if MAR could be predicted by body size and species-specific life-history traits. Using values of MAR collected on European butterflies, we related MAR to 17 life-history traits plus wing size (a correlate of body size). We show that four life-history traits and wing size were significantly related with MAR in European butterflies. Compared to a model with wing size only, the inclusion of these four traits (myrmecophily, thermal tolerance, mate searching strategy, and ovigeny) more than doubled the power of the predictions of MAR. Our study provides a first step towards a predictive theory of species spatial requirements, with strong applications in conservation biology.

On the probability of extinction in a periodic environment

For a certain class of multi-type branching processes in a continuous-time periodic environment, we show that the extinction probability is equal to (resp. less than) 1 if the basic reproduction number R(0) is less than (resp. bigger than) 1. The proof uses results concerning the asymptotic behavior of cooperative systems of differential equations. In epidemiology the extinction probability may be used as a time-periodic measure of the epidemic risk. As an example we consider a linearized SEIR epidemic model and data from the recent measles epidemic in France. Discrete-time models with potential applications in conservation biology are also discussed.

Analytical evidence for scale-invariance in the shape of species abundance distributions

The distribution of species abundances within an ecological community provides a window into ecological processes and has important applications in conservation biology as an indicator of disturbance. Previous work indicates that species abundance distributions might be independent of the scales at which they are measured which has implications for data interpretation. Here we formulate an analytically tractable model for the species abundance distribution at different scales and discuss the biological relevance of its assumptions. Our model shows that as scale increases, the shape of the species abundance distribution converges to a particular shape given uniquely by the Jaccard index of spatial species turnover and by a parameter for the spatial correlation of abundances. Our model indicates that the shape of the species abundance distribution is taxon specific but does not depend on sample area, provided this area is large. We conclude that the species abundance distribution may indeed serve as an indicator of disturbances affecting species spatial turnover and that the assumption of conservation of energy in ecosystems, which is part of the Maximum Entropy approach, should be re-evaluated.

Breeding abundance of threatened raptors as estimated from occurrence data

A model derived from the negative binomial distribution (NBD) has been proposed to solve the problem of predicting abundance of species from occurrence maps. The viability of NBD was explored for predicting the breeding abundance of five threatened species of raptor: Bonelli's Eagle Hieraaetus fasciatus, Golden Eagle Aquila chrysaetos, Peregrine Falco peregrinus, Lanner Falco biarmicus and Lesser Kestrel Falco naumanni. First, the accuracy of the NBD was tested in a reference area where the species abundance and occurrence were known through intensive field surveys. Next, an estimation of regional abundance derived from NBD was made for each species. These estimates were then compared to the existing regional data for the five raptors. The spatial distributions of the species were strongly aggregated, with F. peregrinus correctly showing the most widespread area of occupancy. The NBD gave a good approximation of the breeding abundance of the raptors, but tended to overestimate real data, particularly the regional data for falcons. Difficulties in species detection, insufficient sampling effort (F. biarmicus) or data collected over long time spans when population size increased (F. naumanni) may have reduced the NBD's resolution power. The ability of the method to predict local abundances over large areas from readily available presence‐absence data, with relatively low fieldwork effort, could have considerable applications in conservation biology.

Leveraging the rice genome sequence for monocot comparative and translational genomics

Common genome anchor points across many taxa greatly facilitate translational and comparative genomics and will improve our understanding of the Tree of Life. To add to the repertoire of genomic tools applicable to the study of monocotyledonous plants in general, we aligned Allium and Musa ESTs to Oryza BAC sequences and identified candidate Allium-Oryza and Musa-Oryza conserved intron-scanning primers (CISPs). A random sampling of 96 CISP primer pairs, representing loci from 11 of the 12 chromosomes in rice, were tested on seven members of the order Poales and on representatives of the Arecales, Asparagales, and Zingiberales monocot orders. The single-copy amplification success rates of Allium (31.3%), Cynodon (31.4%), Hordeum (30.2%), Musa (37.5%), Oryza (61.5%), Pennisetum (33.3%), Sorghum (47.9%), Zea (33.3%), Triticum (30.2%), and representatives of the palm family (32.3%) suggest that subsets of these primers will provide DNA markers suitable for comparative and translational genomics in orphan crops, as well as for applications in conservation biology, ecology, invasion biology, population biology, systematic biology, and related fields.

A flexible modelling framework linking the spatio-temporal dynamics of plant genotypes and populations: Application to gene flow from transgenic forests

The dynamics of populations and genotypes are tightly interlinked. We formulate a modelling framework, AMELIE that links the spatio-temporal dynamics of plant populations and genotypes. AMELIE is flexible in the description of life histories, reproductive systems, demographic and environmental stochasticity. It can incorporate alternative submodels for key demographic processes (including arbitrary pollen and seed dispersal kernels). Genotypes are characterized by the combination of two alleles at a bi-parentally inherited locus that may affect any demographic process. We use AMELIE to study how transgene spread from a genetically modified (GM) to a conventional forest depends on the demographic trait modified by the transgene, on transgene expression, and on the initial genotype of GM plants. Transgene spread strongly depends on the interplay between trait modification and transgene expression, which jointly define the ability of heterozygous plants to replace conventional ones. When examining two alternative measures for controlling transgene spread, we find that planting heterozygous GM plants initially reduces transgene spread, whereas transgene recessiveness has more long-term effects on gene flow. The results of this study thus have direct implications for the assessment and management of GM risks. The flexible framework for modelling population–genotype dynamics furthermore has various applications in conservation biology.