Treesearch

We report first-year survival for 34 captive-reared Puerto Rican Parrots (Amazona vittata) released in the Caribbean National Forest, Puerto Rico between 2000 and 2002. The purpose of the releases were to increase population size and the potential number of breeding individuals of the sole extant wild population, and to refine release protocols for eventual reintroduction of a second wild population elsewhere on the island. After extensive prerelease training, we released 10 parrots in 2000, 16 parrots in 2001, and eight parrots in 2002 ranging in age from 1–4 years old. All birds were...

We studied nitrous oxide (N2O) fluxes and soil nitrogen (N) cycling following forest conversion to pasture in the central Amazon near Santarém, Pará, Brazil. Two undisturbed forest sites and 27 pasture sites of 0.5 to 60 years were sampled once each during wet and dry seasons. In addition to soil-atmosphere fluxes of N2O we measured 27 soil chemical, soil microbiological and soil physical variables. Soil N2O fluxes were higher in the wet season than in the dry season. Fluxes of N2O from forest soils always exceeded fluxes from pasture soils and showed no consistent trend with pasture age....

Fine root dynamics have the potential to contribute significantly to ecosystem-scale biogeochemical cycling, including the production and emission of greenhouse gases. This is particularly true in tropical forests which are often characterized as having large fine root biomass and rapid rates of root production and decomposition. We examined patterns in fine root dynamics on two soil types in a lowland moist Amazonian forest, and determined the effect of root decay on rates of C and N trace gas fluxes. Root production averaged 229 (
35) and 153 (
27) gm2 yr1 for years 1 and 2 of the...

A fungus with gelatinous poroid fruiting bodies was found in Puerto Rico and determined by macro- and micromorphology to be most similar to members of the lamellate agaric genus Resupinatus. This species is described as a new species, Resupinatus porosus. Phylogenetic analyses of ribosomal DNA sequences support the inclusion of this fungus in the clade containing Resupinatus, and indicate that this monophyletic group also includes members of Asterotus and the cyphelloid genus Stigmatolemma. Resupinatus porosus is another example of tropical poroid representatives of lamellate agaric...

We compared the bird distributions in the understorey of treefall gaps and sites with intact canopy in Amazonian terra firme forest in Brazil. We compiled 2216 mist-net captures (116 species) in 32 gap and 32 forest sites over 22.3 months. Gap habitats differed from forest habitats in having higher capture rates, total captures, species richness and diversity. Seventeen species showed a significantly different distribution of captures between the two habitats(13 higher in gap and four higher in forest). Gap habitats had higher capture rates for nectarivores, frugivores and insectivores....

Labile carbon is the fraction of soil organic carbon with most rapid turnover times and its oxidation drives the flux of CO2 between soils and atmosphere. Available chemical and physical fractionation methods for estimating soil labile organic carbon are indirect and lack a clear biological definition. We have modified the well-established Jenkinson and Powlson’s fumigation–incubation technique to estimate soil labile organic carbon using a sequential fumigation–incubation procedure. We define soil labile organic carbon as the fraction of soil organic carbon degradable during microbial...

In this chapter, we examine the use of classical methods to study fungal diversity. Classical methods rely on the direct observation of fungi, rather than sampling fungal DNA. We summarize a wide variety of classical methods, including direct sampling of fungal fruiting bodies, incubation of substrata in moist chambers, culturing of endophytes, and particle plating. We also cite and discuss study designs for documenting diversity and monitoring species, and analytical methods that have been used for data produced using classical methods. Selected examples of such mycological studies are...

The advent of the Homogeocene (Putz 1997), Homogecene (McKinney & Lockwood 1999; Lockwood & McKinney 2001) or Homogocene (Lodge & Shrader-Frechette 2003) – the era of human domination of the world – is both a challenge and an opportunity to test the ingenuity of humans. Will we be able to establish a new and sustainable balance with the rest of the world’s biota? To do so requires active management of biodiversity based on understanding the function and dynamics of ecosystems. Appropriately, the approach to the study of the biota is undergoing a shift from a taxonomic, distributional and...

Amazon deforestation has been measured by remote sensing for three decades. In comparison, selective logging has been mostly invisible to satellites. We developed a large-scale, high-resolution, automated remote-sensing analysis of selective logging in the top five timber-producing states of the Brazilian Amazon. Logged areas ranged from 12,075 to 19,823 square kilometers per year (T14%) between 1999 and 2002, equivalent to 60 to 123% of previously reported deforestation area. Up to 1200 square kilometers per year of logging were observed on conservation lands. Each year, 27 million to 50...