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Puerto Limón, Costa Rica

Lott T.A.,University of Florida | Dilcher D.L.,Indiana University Bloomington | Horn S.P.,University of Tennessee at Knoxville | Vargas O.,La Selva Biological Station | Sanford Jr. R.L.,University of Denver
Palaeontologia Electronica | Year: 2011

The Puerto Viejo Pleistocene megafossil flora presented here is based on fossil leaves, fruits, and seeds from the banks of Río Puerto Viejo, Costa Rica. Eleven types of plant megafossils are described in this study, including Laurophyllum, Oxandra, Piperites, Ingeae, Parinari, Sacoglottis, Byrsonima, and Pouteria. Detailed morphological and anatomical data are provided for each taxon. Although the Puerto Viejo site is situated in the Atlantic Lowland Tropical Wet Forest today, the fossil flora suggests a relationship with nearby modern forests at slightly higher elevation, and cooler paleotemperatures than at present. © Palaeontological Association March 2011. Source

Russell A.E.,Iowa State University | Raich J.W.,Iowa State University | Arrieta R.B.,La Selva Biological Station | Valverde-Barrantes O.,Kent State University | Gonzalez E.,University of Costa Rica
Ecological Applications | Year: 2010

In the moist tropical forest biome, which cycles carbon (C) rapidly and stores huge amounts of C, the impacts of individual species on C balances are not well known. In one of the earliest replicated experimental sites for investigating growth of native tropical trees, we examined traits of tree species in relation to their effects on forest C balances, mechanisms of influence, and consequences for C sequestration. The monodominant stands, established in abandoned pasture in 1988 at La Selva Biological Station, Costa Rica, contained five species in a complete randomized block design. Native species were: Hieronyma alchorneoides, Pentaclethra macroloba, Virola koschnyi, and Vochysia guatemalensis. The exotic species was Pinus patula. By 16 years, the lack of differences among species in some attributes suggested strong abiotic control in this environment, where conditions are very favorable for growth. These attributes included aboveground net primary productivity (ANPP), averaging 11.7 Mg C·ha-1·yr-1 across species, and soil organic C (0-100 cm, 167 Mg C/ha). Other traits differed significantly, however, indicating some degree of biological control. In Vochysia plots, both aboveground biomass of 99 Mg C/ha, and belowground biomass of 20 Mg C/ha were 1.8 times that of Virola (P = 0.02 and 0.03, respectively). Differences among species in overstory biomass were not compensated by understory vegetation. Belowground NPP of 4.6 Mg C·ha -1·yr-1 in Hieronyma was 2.4 times that of Pinus (P < 0.01). Partitioning of NPP to belowground components in Hieronyma was more than double that of Pinus (P = 0.03). The canopy turnover rate in Hieronyma was 42% faster than that of Virola (P < 0.01). Carbon sequestration, highest in Vochysia (7.4 Mg C·ha-1·yr-1, P = 0.02), averaged 5.2 Mg C·ha-1·yr-1, close to the annual per capita fossil, fuel use in the United States of 5.3 Mg C Our results indicated that differences in species effects on forest C balances were related primarily to differences in growth rates, partitioning of C among biomass components, tissue turnover rates, and tissue chemistry. Inclusion of those biological attributes may be critical for robust modeling of C cycling across the moist tropical forest biome. © 2010 by the Ecological Society of America. Source

Feeley K.J.,Florida International University | Feeley K.J.,Fairchild Tropical Botanic Garden | Hurtado J.,La Selva Biological Station | Saatchi S.,Jet Propulsion Laboratory | And 3 more authors.
Global Change Biology | Year: 2013

Species are predicted to shift their distributions upslope or poleward in response to global warming. This prediction is supported by a growing number of studies documenting species migrations in temperate systems but remains poorly tested for tropical species, and especially for tropical plant species. We analyzed changes in tree species composition in a network of 10 annually censused 1-ha plots spanning an altitudinal gradient of 70-2800 m elevation in Costa Rica. Specifically, we combined plot data with herbarium records (accessed through GBIF) to test if the plots' community temperature scores (CTS, average thermal mean of constituent species weighted by basal area) have increased over the past decade as is predicted by climate-driven species migrations. In addition, we quantified the contributions of stem growth, recruitment, and mortality to the observed patterns. Supporting our a priori hypothesis of upward species migrations, we found that there have been consistent directional shifts in the composition of the plots, such that the relative abundance of lowland species, and hence CTS, increased in 90% of plots. The rate of the observed compositional shifts corresponds to a mean thermal migration rate (TMR) of 0.0065 °C yr-1 (95% CI = 0.0005-0.0132 °C yr-1). While the overall TMR is slower than predicted based on concurrent regional warming of 0.0167 °C yr-1, migrations were on pace with warming in 4 of the 10 plots. The observed shifts in composition were driven primarily by mortality events (i.e., the disproportionate death of highland vs. lowland species), suggesting that individuals of many tropical tree species will not be able to tolerate future warming and thus their persistence in the face of climate change will depend on successful migrations. Unfortunately, in Costa Rica and elsewhere, land area inevitably decreases at higher elevations; hence, even species that are able to migrate successfully will face heightened risks of extinction. © 2013 John Wiley & Sons Ltd. Source

Haber W.A.,Apdo. 50 5655 | Wagner D.L.,University of Connecticut | De La Rosa C.,La Selva Biological Station
Zootaxa | Year: 2015

We describe a new species, Erythrodiplax laselva (Libellulidae), that breeds in bromeliads and Cochliostema (Commelinaceae) in the eastern lowlands of Costa Rica. The closest known relative is thought to be E. castanea, widespread in Central and South America, and not E. bromeliicola, which is known to breed in bromeliads in Cuba and Jamaica. The male, female, genitalia, and larva are described and illustrated. Copyright © 2015 Magnolia Press. Source

Clark D.B.,University of Missouri-St. Louis | Hurtado J.,La Selva Biological Station | Saatchi S.S.,Jet Propulsion Laboratory
PLoS ONE | Year: 2015

Rapid biological changes are expected to occur on tropical elevational gradients as species migrate upslope or go extinct in the face of global warming. We established a series of 9 1-ha plots in old-growth tropical rainforest in Costa Rica along a 2700 m relief elevational gradient to carry out long-term monitoring of tropical rain forest structure, dynamics and tree growth. Within each plot we mapped, identified, and annually measured diameter for all woody individuals with stem diameters >10 cm for periods of 3-10 years. Wood species diversity peaked at 400-600 m and decreased substantially at higher elevations. Basal area and stem number varied by less than two-fold, with the exception of the 2800 m cloud forest summit, where basal area and stem number were approximately double that of lower sites. Canopy gaps extending to the forest floor accounted for <3% of microsites at all elevations. Height of highest crowns and the coefficient of variation of crown height both decreased with increasing elevation. Rates of turnover of individuals and of stand basal area decreased with elevation, but rates of diameter growth and stand basal area showed no simple relation to elevation. We discuss issues encountered in the design and implementation of this network of plots, including biased sampling, missing key meteorological and biomass data, and strategies for improving species-level research. Taking full advantage of the major research potential of tropical forest elevational transects will require sustaining and extending ground based studies, incorporation of new remotely-sensed data and data-acquisition platforms, and new funding models to support decadal research on these rapidly changing systems. Source

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