Well-Read-Robyn_4_30_15

Compilation by Robyn Darbyshire

Bar-Massada, A., V. C. Radeloff, et al. (2014). “Biotic and Abiotic Effects of Human Settlements in the Wildland–Urban Interface.” BioScience 64(5): 429-437.

The wildland–urban interface (WUI) is the area in which human settlements adjoin or intermix with ecosystems. Although research on the WUI has been focused on wildfire risk to settlements, we argue here that there is a need to quantify the extent of areas in which human settlements interact with adjoining ecosystems, regardless of their ability to support fire spread. Besides wildfires, human settlements affect neighboring ecosystems through biotic processes, including exotic species introduction, wildlife subsidization, disease transfer, landcover conversion, fragmentation, and habitat loss. The effects of WUI settlements on ecosystems are two tiered, starting with habitat modification and fragmentation and progressing to various diffusion processes in which direct and indirect effects of anthropogenic activities spread into neighboring ecosystems at varying scales. New scientific, management, and policy tools are needed in order to better understand the WUI as a unique social–ecological zone and to mitigate negative consequences of its continued growth.

FULL TEXT LINK:

http://bioscience.oxfordjournals.org/content/64/5/429.abstract

 

Carwardine, J., C. Hawkins, et al. (2015). “Spatial Priorities for Restoring Biodiverse Carbon Forests.” BioScience 65(4): 372-382.

A price on carbon is driving land-use changes globally, including the establishment of biodiverse carbon plantings to sequester carbon. The biodiversity benefits of these plantings depend on many factors, including their spatial locations. We provide an approach for assessing the opportunities and spatial priorities for carbon sequestration and biodiversity restoration through biodiverse carbon plantings. Using Australia as a case study, we show how carbon market conditions affect the potential for achieving biodiversity benefits through restoring heavily cleared vegetation types to 30% of their original extent. Using a midrange carbon price, AU$20 per ton, we discovered that the top 25% of priority areas for biodiverse carbon plantings could sequester 132 megatons of carbon dioxide equivalents annually—more than 5% of Australia’s emissions. Lower carbon prices limit biodiversity outcomes. Spatial priorities for sequestering carbon are different from those for restoring biodiversity; therefore, accounting for both factors maximizes efficiency and opportunities.

FULL TEXT LINK: http://bioscience.oxfordjournals.org/content/65/4/372.abstract

 

Sloat, M. R. and G. H. Reeves (2014). “Demographic and phenotypic responses of juvenile steelhead trout to spatial predictability of food resources.” Ecology 95(9): 2423-2433.

We manipulated food inputs among patches within experimental streams to determine how variation in foraging behavior influenced demographic and phenotypic responses of juvenile steelhead trout (Oncorhynchus mykiss) to the spatial predictability of food resources. Demographic responses included compensatory adjustments in fish abundance, mean fish size, and size inequality. These responses paralleled shifts in individual foraging behavior, which increased the strength of exploitative competition relative to interference competition in streams with lower spatial predictability of food resources. Variation in the spatial predictability of food resources also favored different physiological phenotypes, as inferred from selection on an index of standard metabolic rate (SMR) based on fish otolith size. We observed positive directional selection on SMR in streams with spatially predictable food resources, disruptive selection for SMR at intermediate levels of spatial predictability, and negative directional selection for SMR in streams with the lowest level of spatial predictability of food resources. Thus, variation in the spatial predictability of food resources resulted in changes in individual behavior and modes of population regulation, and produced physiologically divergent cohorts of stream salmonids.

FULL TEXT LINK: http://dx.doi.org/10.1890/13-1442.1

 

Balfour, V. N., S. H. Doerr, et al. (2014). “The temporal evolution of wildfire ash and implications for post-fire infiltration.” International Journal of Wildland Fire 23(5): 733-745.

Changes in the properties of an ash layer with time may affect the amount of post-fire runoff, particularly by the formation of ash surface crusts. The formation of depositional crusts by ash have been observed at the pore and plot scales, but the causes and temporal evolution of ash layers and associated crusts have not yet been thoroughly investigated. In the long term, ash crusting effects will decrease as the ash layer is removed by wind and water erosion, but in the short term ash crusting could contribute to the observed changes in post-fire runoff. This research addresses these topics by studying the evolution over time of highly combusted ash layers from two high-severity wildfires that occurred in Montana in 2011. More specifically, this research was designed to assess the potential for ash crusts to form and thereby contribute to the observed decreases in infiltration after forest fires. Results indicate that high-combustion ash can evolve due to post-fire rainfall. Plots that exhibited a visible ash crust also displayed a significant decrease in effective porosity and hydraulic conductivity. These decreases in ash layer characteristics were attributed to raindrop compaction and ash hydration resulting in the formation of carbonate crystals, which decreased effective porosity and flow within the ash layer. During this same time period, inorganic carbon content more than doubled from 11 to 26% and bulk density significantly increased from 0.22 to 0.39 g cm–3 on crusted plots. Although raindrop impact increased the robustness of the ash crust, mineralogical transformations must occur to produce a hydrologically relevant ash crust. These results indicate that post-fire rainfall is an important control on the properties of the ash layer after burning and on crust formation. The observed temporal changes indicate that the timing of ash sampling can alter the predictions as to whether the ash layer is effecting post-fire infiltration and runoff. Despite the reduction in infiltration capacity, the formation of post-fire ash crusts could prove beneficial to post-fire hazard mitigation by stabilising the ash layer, and reducing aeolian mixing and erosion.

FULL TEXT LINK: http://www.publish.csiro.au/paper/WF13159

 

Siegel, R. B., R. L. Wilkerson, et al. (2014). “Roost sites of the Black-backed Woodpecker in burned forest.” Western Birds 45(4): 296-303.

The Black-backed Woodpecker (Picoides arcticus) is strongly associated with recently burned forest, which makes it vulnerable to salvage logging or other post-fire forest management that removes snags. As part of a larger radio-telemetry study of the species’ resource use and habitat selection in a burned forest in California, we located radio-tagged Black-backed Woodpeckers at night to find and describe their roost sites. We found 14 unique roost locations during night-time searches for five individual birds. Description of the micro-site on the tree that the bird used was impossible at five roosts where we could not visually locate the bird in the dark. At the nine roosts confirmed visually, none of the birds roosted in excavated cavities. Rather, they roosted in sheltered spaces within burned-out hollows of trunks (5 instances), in the crook of a forked trunk (1 instance), wedged between adjacent trunks of two closely spaced trees (1 instance), in a deep, natural bark furrow (1 instance), and clinging to a trunk directly above a horizontal branch (1 instance). Eleven of the 14 roosts (79%) were in dead trees. Our results suggest that in burned forests the Black-backed Woodpecker may benefit if, during salvage logging, emphasis is placed on retaining snags with burned-out hollows, forked trunks, or other relatively unusual structures that may create crevices or other opportunities for shelter.

NO FULL TEXT LINK: full text available from FS Library Services http://fsweb.wo.fs.fed.us/library/document-delivery.htm