Treesearch

River flow can impact which sources of particulate organic matter (POM) fuel estuarine food webs. Here, we used stable carbon (C) and nitrogen (N) isotope analyses to compare how contributions of diff erent POM sources (terrestrial, estuarine, and marine) to the diets of zooplankton and juvenile fishes differed between low and high river flow conditions, as well as spatially across a tropical estuary, Hilo Bay, Hawaii, USA. Diets of zooplankton and juvenile fishes were affected by river flow conditions, but the magnitude and the change in the basal resources depended on the location of the...

Management of forest carbon (C) stocks is an increasingly prominent land-use issue. Knowledge of carbon storage in tropical forests is improving, but regional variations are still poorly understood, and this constrains forest management and conservation efforts associated with carbon valuation mechanisms (e.g., carbon markets). This deficiency is especially pronounced in tropical islands and low-lying coastal areas where climate change impacts are expected to be among the most severe. This study presents the first field estimate of island-wide carbon storage in ecosystems of Oceania, with...

Structurally complex mangrove roots are thought to provide foraging habitat, predation refugia, and typhoon protection for resident fish, shrimp, and crabs. The spatially compact nature of Micronesian mangroves results in model ecosystems to test these ideas. Tidal creek nekton assemblages were compared among mangrove forests impacted by Typhoon Sudal and differing in stand structure. Structurally complex Rhizophora spp. stands were predicted to support higher densities and different communities of nekton and to provide greater protection from typhoons compared to less complex Sonneratia...

Horticultural nurseries are heterogeneous and spatially complex agricultural systems, which present formidable challenges to management of diseases and pests. Moreover, nursery plants shipped interstate and internationally can serve as important vectors for pathogens and pests that threaten both agriculture and forestry. Current regulatory strategies to prevent this movement of pathogens and pests with nursery plants are based on visual inspections of plants just before shipping, a process that is costly and inadequate. Here we propose the application of a systems approach for horticultural...

The wood oils of Pinus jeffreyi and P. sabiniana contain considerable amounts of heptane (76.6%, 92%), on a monoterpene basis. However, when entire wood extractables is considered, the amounts drop considerably (3.4%, 36.8%) with the major portion of the wood oils being diterpene acids. The leaf oil of P. jeffreyi is dominated by α-pinene (20.9%) and, a diterpene, thunbergol (9.2%) with moderate amounts of β-pinene, δ-3-carene, limonene, β-phellandrene, (Z)-β-ocimene, (E)-caryophyllene, δ-cadinene and cembrene. The leaf oil of P. sabiniana is dominated by α-pinene (39.1%) with moderate...

Defining best management practices for forests requires quantification of the variability of stream sediment loads for managed and unmanaged forest conditions and their associated sediment sources. Although "best management practices" are used, the public has concerns about effects from forest restoration activities and commercial timber harvests. It is necessary to know the current and/or natural range of variability to be able to determine if management activity has a significant negative impact; only long-term research can provide such data. The Forest Service in the United States has...

Conifers comprise an ancient and widespread plant lineage of enormous commercial and ecological value. However, compared to model woody angiosperms, such as Populus and Eucalyptus, our understanding of conifers remains quite limited at a genomic level. Large genome sizes (10,000-40,000 Mbp) and large amounts of repetitive DNA have limited efforts to produce a conifer reference genome, and genomic resource development has focused primarily on characterization of expressed sequences. Here we report the completion of a conifer transcriptome sequencing project undertaken in collaboration with...

A high spatial resolution QuickBird satellite image and a low spatial but high spectral resolution Landsat Thermatic Mapper image were used to linearly regress fuel loads of 70 plots with size 30X30m over the Daxinganling region of north-east China. The results were compared with loads from field surveys and from regression estimations by surveyed stand characteristics. The results show that fuel loads were related to stand characteristics, such as stand mean diameter at breast height and stand height. As the QuickBird image using the shadow fraction method represented the stand characteris...