Treesearch

Stubble height, streambank alteration, and woody species use are indicators used to monitor livestock impacts on riparian areas in the western United States. Effects of wild ungulates on riparian conditions are often not monitored and assumed to be represented by indicators developed for livestock. We tested this assumption by evaluating effects of elk (Cervus canadensis) and mule deer (Odocoileus hemionus) on grazing indicators along Meadow Creek, a salmonid-bearing stream in northeastern Oregon. Wild ungulates reduced stubble height by 20% to 30%. Mean streambank alteration was 1.1%...

Family forest owners in the United States have an important role in providing social and ecological benefits across landscapes. Thus, a detailed understanding of their land management behavior is critical to determine whether or not these benefits will be realized. In this paper, we report on a vote-count meta-analysis of peerreviewed quantitative studies in the U.S. to examine an array of forest landowner behaviors. We extend other reviews of this literature by including papers with any behavioral dependent variable, rather than only timber harvesting or land management behavior. We...

Natural forests are increasingly invaded by nonnative pests and pathogens that threaten host species with population extirpation and cascading ecological impacts. The regeneration for resilience (R4R) framework provides a decision structure to prioritize limited resources and utilize artificial and natural regeneration management to offer the best likelihood of success in positioning stands and landscapes to support multi-generational selfsustaining host populations in the presence of the nonnative invader by (1) increasing host population size to offset invader-caused mortality, (2)...

Pedogenic processes imprint their signature on soils over the course of thousands to millions of years in most soil systems. Variation in soil forming processes - such as parent material weathering, organic material additions, hydrologic processes, and atmospheric additions - account for the distribution and sourcing of cations in ecosystems, and hence exert a strong influence on ecosystem productivity. Soil nutrient dynamics of cations also provide an indication of the dominant soil forming processes at work in a particular system. To gain insight into the generation and distribution of...

Monitoring understory plant diversity is important, allowing managers to track current diversity status and trends both spatially and temporally at a landscape-scale. Improving precision in quantifying patterns in understory plant diversity improves efficiency in monitoring design and more accurate measures of success of management intervention over time. Patterns of species diversity are dependent upon the scale in which they are examined - an increase in small-scale diversity across a gradient can convert to a decrease in large-scale diversity across that same gradient. Using two...

Large, high-severity wildfires alter the physical and biological conditions that determine how catchments retain and release nutrients and regulate streamwater quality. The short-term water quality impacts of severe wildfire are often dramatic, but the longer-term responses may better reflect terrestrial and aquatic ecosystem recovery. We followed streamwater chemistry for 14 years after the largest fire in recorded Colorado history, the 2002 Hayman Fire, to characterize patterns in nitrogen (N) and carbon (C) export. Throughout the postfire period, stream nitrate and total dissolved N...

One of the primary physiological issues with cultivation of pomegranate (Punica granatum L. cv Post Sefid Darjazin) is excessive fruit cracking. Foliar applications of chemical and organic mixtures to limit or prevent pomegranate cracking were evaluated in this work. This 2 year study (2014–2015) was conducted in Darjazin, Iran and designed to evaluate the impacts of foliar application of 2 and 5mll–1 humic acid, 6% kaolin, and 3% Calcium-1% Boron (CB) separately or in combination. Pomegranate fruits were examined under two irrigation regimes at three time periods during the growing...

The objective of this paper is to present a relatively simplified model to predict daily water table (WT) by solving ordinary differential equation dWT (t)/dt = F (α1, α2, α3, WT0(t), RF (t), PET (t)), with α1, α2, α3, WT0 as parameters, and RF (rainfall) and PET (potential evapotranspiration), respectively, as inputs. The model was calibrated and validated with WT on four poorly to moderately drained soils (Lenoir, Rains, Lynchburg, and Goldsboro) on a forested wetland. Calibration results were in good agreement with the measured WT for all soils, except the Goldsboro with deeper WT. r2...

Dormancy break and germination requirements for Quercus pagoda (Raf.) acorns were determined, as well as the effects of acorn pretreatment and post-germination temperatureson epicotyl emergence, seedling development, and seedling biomass accumulation.There was an inverse linear relationship between length of cold stratification (5/1 °C for0–12 weeks) and cumulative germination percentages in all incubation temperatures (15/6,20/10, 25/15, 30/20 °C). Acorns required 12 weeks of cold stratification to break dormancy.Gibberellic acid substituted for cold stratification; although, it was not...

In this study, we evaluated 'Crandon' coarse root biomass and architecture grown at different topographic positions and fertilizer rates. Complete excavations were conducted on a subset of trees after the first growing season and showed that root biomass was strongly related to stem biomass (R2 = 0.93), but not topographic position or fertilizer rate. After the third growing season, subsamples of roots were collected from another subset of trees and showed coarse root architecture variables to be strongly related to several metrics of the tree and root size (R2 = 0.61 to 0.82), while also...