The adaptive potential of species is disrupted with the substantial reduction of their reproductive success (e.g., lower seed production, fruit set, viability, germination and seedling establishment, Mitton Nason and Hamrick ). Habitat fragmentation promotes a reduction of gene flow between populations, allele loss through the effect of genetic drift and increased levels of inbreeding. We propose a conservation strategy for these important pine species in order to increase their long-term genetic viability.įragmentation and habitat degradation due to natural disturbance regimes and increasing anthropogenic land use changes have caused the natural populations of plants to become smaller and isolated and subjected to negative genetic and demographic consequences. This result indicates that fragmentation has played a more important role in the reproductive success of Rzedowski’s pine than in veitchii pine, perhaps by limiting pollen flow among zones and populations and producing higher levels of inbreeding and lower seed efficiency in the former species. Reproductive indicators differed significantly among zones and populations for each species, where fragment sizes mainly affected seed production and efficiency. In contrast, veitchii pine presents moderate seed efficiency (54.9%), high germination (71.5%) and seedling establishment (84%–97%) and low inbreeding (0.33). We found that the reproductive success of Rzedowski’s pine seems to be critical, presenting low seed efficiency (17.10%), germination (5.0%) and seedling establishment (27.7%), with high levels of inbreeding (0.79). These traits were systematically quantified and their variation assessed using Generalized Linear Mixed Models (GLMMs). veitchii (Shaw)) in west-central Michoacán, Mexico. We analyze cone and seed traits as indicators of reproductive success in the endangered Rzedowski´s pine ( Pinus rzedowskii (Madrigal et Caballero) and near-threatened veitchii pine ( Pinus ayacahuite var. Monitoring of these parameters is essential to determine the viability of populations for the purposes of conservation. Seed production, quality, germination and seedling establishment are indicators of reproductive success in conifers.
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