Predictability of demographic rates based on phylogeny and biological similarity

Lack of demographic data for most of the world's threatened species is a widespread problem that precludes viability-based status assessments for species conservation. A commonly suggested solution is to use data from species that are closely related or biologically similar to the focal species. This approach assumes similar species and populations of the same species have similar demographic rates, an assumption that has yet to be thoroughly tested. We constructed a Bayesian hierarchical model with data on 425 plant species to predict demographic rates (intrinsic rate of population growth, recruit survival, juvenile survival, adult survival, and fecundity) based on biological traits and phylogenetic relatedness. Generally, we found small effects of species-level traits (except woody polycarpic species tended to have high adult survival rates that increased with plant height) and a weak phylogenetic signal for 4 of the 5 demographic parameters examined. Patterns were stronger in adult survival and fecundity than other demographic rates; however, the unexplained variances at both the species and population levels were high for all demographic rates. For species lacking demographic data, our model produced large, often inaccurate, prediction intervals that may not be useful in a management context. Ourfindings do not support the assumption that biologically similar or closely related species have similar demographic rates and provide further evidence that direct monitoring of focal species and populations is necessary for informing conservation status assessments. La falta de datos demográficos para la mayoría de las especies amenazadas del mundo es un problema ampliamente distribuido que descarta las evaluaciones de estado basadas en la viabilidad para la conservación de las especies. Una sugerencia común es el uso de datos de otras especies que están relacionadas de manera cercana o que son similares biológicamente a la especiefocal. Esta estrategia asume que las especies similares y poblaciones de la misma especie tienen tasas demográficas similares, una suposición que aún no ha sido probada minuciosamente. Construimos un modelo bayesiano de jerarquías con datos de 425 especies de plantas para predecir las tasas demográficas (tasa intrínseca de crecimiento poblacional, supervivencia de reclutas, supervivencia de juveniles, supervivencia de adultos, y fecundidad) con base en los rasgos biológicos y las relacionesfilogenéticas. En general, encontramos efect