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Mountainous land in Haiti is highly degraded following decades of deforestation and erosion. Although mountainous landscapes represent an important target for forest recovery, there is a lack of empirical information to guide reforestation of sloping tropical lands. Using sapling survival data from 299 replicated reforestation plots planted with 24 dry forest species during 2007–2008 in Haiti, we examined the association of sapling survival with topographical, climatic, and landscape level variables. Our analysis indicates that the total number of surviving saplings was strongly correlated to sites with higher water availability, including sites with greater precipitation in dry months and sites with cooler (N/E) exposures. Sites with more adult remnant trees had higher sapling survival. Sapling survival was also improved by the use of best management practices of building micro-catchments and planting multiple sapling species into reforestation plots. Year effects were also significant and modified the effects of exposure, nurse trees, and soil rockiness. This temporal variation suggests sapling responses to environmental factors are sensitive to variation in rainfall.

For habitat restoration, seed of native plant species is frequently transferred over wide geographic areas and planted in environments that differ from the original collection environment. When such collections are grown for seed production in agricultural fields, the genotypes favored under agronomic conditions may differ from those favored at the eventual planting location. The resulting agronomically-produced seed may be poorly matched to intended restoration sites. Populations of two native perennial grasses commonly used in restoration projects in California were grown in typical agronomic conditions for seed production. We compared traits of the plants produced from seed harvested in the first and second years of agronomic production to plants produced from the original seed collections. We found strong evidence for genetic shifts in both species as a result of selection associated with biotic and abiotic factors. A four-population mixture of Elymus glaucus produced seed comprised mainly of two populations, primarily due to differential sensitivity to disease. With two populations of Nassella pulchra , early and late harvests selected for early and late maturing genotypes, respectively, and a reduction in the variance in phenology within the seed from the early harvest. We found that agronomic techniques for seed production have the potential to cause unintentional genotypic selection and result in shifts away from the genetic composition of the original seed collection. We offer recommendations for seed increase protocols to reduce these outcomes.

It is important to predict which invasive species will benefit from future changes in climate, and thereby identify those invaders that need particular attention and prioritization of management efforts. Because establishment, persistence, and spread determine invasion success, this prediction requires detailed demographic information. Explicit study of the impact of pattern on demographic response is particularly important for species that are naturally patchy, such as the invasive grass, Aegilops triuncialis. In the northern California Coast Range, where climate change may increase or decrease mean annual rainfall, we conducted a field experiment to understand the interaction of climate change and local-scale patterning on the demography of A. triuncialis. We manipulated precipitation (reduced, ambient, or augmented), seed density, and seeding pattern. Demographic and environmental data were collected for three years following initial seeding. Pattern and scale figure prominently in the demographic response of A. triuncialis to precipitation manipulation. Pattern interacts with precipitation and seeding density in its influence on per-plant seed output. Although per-plot seed production was highest when seeds were not aggregated, per-plant seed output was higher in aggregated patches. Results suggest aggregation of invasive A. triuncialis reduces the detrimental impact of interspecific competition in its invaded community, and that interspecific competition per se has a stronger impact than intraspecific competition.