Treesearch

Estimation of belowground carbon stocks in tropical wetland forests requires funding for laboratory analyses and suitable facilities, which are often lacking in developing nations where most tropical wetlands are found. It is therefore beneficial to develop simple analytical tools to assist belowground carbon estimation where financial and technical limitations are common. Here we use published and original data to describe soil carbon density (kgCm−3; Cd) as a function of bulk density (gC cm−3; Bd), which can be used to rapidly estimate belowground carbon storage using Bd measurements...

Foliar nitrogen has been shown to be positively correlated with midsummer canopy albedo and canopy near infrared (NIR) reflectance over a broad range of plant functional types (e.g., forests, grasslands, and agricultural lands). To date, the mechanism(s) driving the nitrogen-albedo relationship have not been established, and it is unknown whether factors affecting nitrogen availability will also influence albedo. To address these questions, we examined variation in foliar nitrogen in relation to leaf spectral properties, leaf mass per unit area, and leaf water content for three deciduous...

To better understand the diversity and ecology of indigenous arthropods at risk from the invasive emerald ash borer (Agrilus planipennis Fairmaire) in North American forests, saproxylic beetles (Insecta: Coleoptera) were reared from ash (Fraxinus sp.) limbs suspended in the canopy, ~10–17m above the ground, and from those placed on the ground in a mature mixed hardwood forest. In total, 209 specimens from 9 families and 18 species were collected from 30.0m2 of limbs. The generalist cerambycid Neoclytus acuminatus (Fabricius) was the most commonly captured taxon, followed by an assemblage...

Fernleaf biscuitroot naturally occurs from British Columbia and Saskatchewan south to California and New Mexico and extends eastward to Wyoming and Colorado. Seed matures in July into August. Wildland seed disarticulates readily and is easily hand collected. Very clean collections can be made by shaking ripened inflorescences over a bag or tarp.

Indian ricegrass (Achnatherum hymenoides [Roemer & J.A. Schultes] Barkworth) is a widely distributed, highly desirable native species in desert ecosystems in the western United States. Yet there are no studies linking genetic variation in Indian ricegrass with climate across major areas of its natural distribution. In this study, seeds from 106 collection locations from the southwestern United States were established in common gardens and four phenological traits (Phen; such as blooming date), six production traits (Pro; such as dry weight), and eight morphology traits (Morph; such as leaf...

Recent studies have highlighted the importance of the post-fledging period to bird populations, suggesting that the importance of this portion of the life cycle is equal to or greater than the nesting period. Nevertheless, few studies have compared abundance of forest nesting species between mature forest and early-successional habitats while controlling for differences in detectibility and for biases associated with comparing low stature shrubby vegetation and tall stature forests. We investigated habitat use by forest-nesting birds during the post-fledging period in 2004 using both point...

We monitored 15 radio-collared raccoons (Procyon lotor) on Davies Island in March 1987 - May 1988 to determine the extent to which individual tree attributes or spatial configuration of plant associations (habitat types) across the land-scape influenced den use. Of 1091 verified den sites, 428 were in tree cavities. Raccoon occurrence among 4 cover types differed from that expected based on the total area of each across the island and varied across all seasons for all habitat types except Cedar Wood. Preference varied among age and sex groups and across seasons with some groups showing...

Seasonal forest pools (SFPs) are common, widespread, and provide critical habitat for amphibians and invertebrates. The ephemeral hydrology of SFPs has been identified as an important factor in the production of biologically active methylmercury (MeHg). To investigate mercury (Hg) in SFPs, we collected water, fine benthic organic matter (FBOM), detrital materials, and faunal samples from 10 pools in Massachusetts and Minnesota, across a range of basin morphometry, water chemistry, canopy closure, and hydroperiod. Total Hg (THg) and MeHg concentrations were comparable to other small, lentic...

The influence of sampling strategy on estimates of effective population size (Ne) from single-sample genetic methods has not been rigorously examined, though these methods are increasingly used. For headwater salmonids, spatially close kin association among age-0 individuals suggests that sampling strategy (number of individuals and location from which they are collected) will influence estimates of Ne through family representation effects. We collected age-0 brook trout by completely sampling three headwater habitat patches, and used microsatellite data and empirically parameterized...

Modelling approaches for relating discharge to the biology of Atlantic salmon, Salmo salar L., and brown trout, Salmo trutta L., growing in rivers are reviewed. Process-based and empirical models are set within a common framework of input of water flow and output of characteristics of fish, such as growth and survival, which relate directly to population dynamics. A continuum is envisaged incorporating various contributions of process and empirical structure as practical and appropriate to specific goals. This framework is compared with, and shown to differ from, approaches whose output is...