Life Sciences Commons^™

Differential Effects Of Canopy Trimming And Litter Deposition On Litterfall And Nutrient Dynamics In A Wet Subtropical Forest, Steven J. Hall, Whendee L. Silver, Grizelle González

Steven J. Hall

Humid tropical forests have the highest rates of litterfall production globally, which fuels rapid nutrient recycling and high net ecosystem production. Severe storm events significantly alter patterns in litterfall mass and nutrient dynamics through a combination of canopy disturbance and litter deposition. In this study, we used a large-scale long-term manipulation experiment to explore the separate and combined effects of canopy trimming and litter deposition on litterfall rates and litter nutrient concentrations and content. The deposition of fine litter associated with the treatments was equivalent to more than two times the annual fine litterfall mass and nutrient content in control …

Changing Forest Structure Across The Landscape Of The Sierra Nevada, Ca, Usa, Since The 1930s, Christopher R. Dolanc, Hugh D. Safford, James H. Thorne, Solomon Z. Dobrowski

Forest Management Faculty Publications

Understanding the dynamics of forest structure aids inference regarding future forests and their distributions around the world. Over the last few decades, several papers have addressed changing forest structure in the Sierra Nevada, CA, USA, but these studies were limited in scope. We carried out a broad comparison of forest density and composition in the 1930s versus the 2000s for the west slope of the central and northern Sierra Nevada, using the two most extensive data sets available. Forests in this region have endured a long, complex history of human disturbance, and are now experiencing climatic shifts. We subdivided the …

Can Fire Atlas Data Improve Species Distribution Model Projections?, Shawn M. Crimmins, Solomon Z. Dobrowski, Alison R. Mynsberge, Hugh D. Safford

Forest Management Faculty Publications

Correlative species distribution models (SDMs) are widely used in studies of climate change impacts, yet are often criticized for failing to incorporate disturbance processes that can influence species distributions. Here we use two temporally independent data sets of vascular plant distributions, climate data, and fire atlas data to examine the influence of disturbance history on SDM projection accuracy through time in the mountain ranges of California, USA. We used hierarchical partitioning to examine the influence of fire occurrence on the distribution of 144 vascular plant species and built a suite of SDMs to examine how the inclusion of fire-related predictors …

Management For Mountain Pine Beetle Outbreak Suppression: Does Relevant Science Support Current Policy?, Diana Six, Eric Biber, Elisabeth Long

Ecosystem and Conservation Sciences Faculty Publications

While the use of timber harvests is generally accepted as an effective approach to controlling bark beetles during outbreaks, in reality there has been a dearth of monitoring to assess outcomes, and failures are often not reported. Additionally, few studies have focused on how these treatments affect forest structure and function over the long term, or our forests’ ability to adapt to climate change. Despite this, there is a widespread belief in the policy arena that timber harvesting is an effective and necessary tool to address beetle infestations. That belief has led to numerous proposals for, and enactment of, significant …

Monteverde: Ecology And Conservation Of A Tropical Cloud Forest - 2014 Updated Chapters, Nalini M. Nadkarni, Nathaniel T. Wheelwright

Bowdoin Scholars' Bookshelf

The Monteverde Cloud Forest Reserve has captured the worldwide attention of biologists, conservationists, and ecologists and has been the setting for extensive investigation over the past 40 years. Roughly 40,000 ecotourists visit the Cloud Forest each year, and it is often considered the archetypal high-altitude rain forest. “Monteverde: Ecology and Conservation of a Tropical Cloud Forest”, edited by Nalini Nadkarni and Nathaniel T. Wheelwright (Oxford University Press, 2000 and Bowdoin’s Scholar’s Bookshelf. Book 1 ), features synthetic chapters and specific accounts written by more than 100 biologist and local residents, presenting in a single volume everything known in 2000 about …

Changing Forest Water Yields In Response To Climate Warming: Results From Long-Term Experimental Watershed Sites Across North America, Irena F. Creed, Adam T. Spargo, Julia A. Jones, Jim M. Buttle, Mary B. Adams, Fred D. Beall, Eric G. Booth, John L. Campbell, Dave Clow, Kelly Elder, Mark B. Green, Nancy B. Grimm, Chelcy Miniat, Patricia Ramlal, Amartya Saha, Stephen Sebestyen, Dave Spittlehouse, Shannon Sterling, Mark W. Williams, Rita Wrinkler, Huaxia Yao

USDA Forest Service / UNL Faculty Publications

Climate warming is projected to affect forest water yields but the effects are expected to vary. We investigated how forest type and age affect water yield resilience to climate warming. To answer this question, we examined the variability in historical water yields at long-term experimental catchments across Canada and the United States over 5-year cool and warm periods. Using the theoretical framework of the Budyko curve, we calculated the effects of climate warming on the annual partitioning of precipitation (P) into evapotranspiration (ET) and water yield. Deviation (d) was defined as a catchment’s change in actual ET divided by P …

Drought-Induced Woody Plant Mortality In An Encroached Semi-Arid Savanna Depends On Topoedaphic Factors And Land Management, Dirac L. Twidwell Jr, Carissa L. Wonkka, Charles A. Taylor, Chris B. Zou, Jeremiah J. Twidwell, William E. Rogers

Department of Agronomy and Horticulture: Faculty Publications

Questions: How do recent patterns of drought-induced woody plant mortality in Texas semi-arid savanna compare to the extended drought of the 1950s? Does the relative composition of the woody plant community shift ubiquitously across the landscape following woody plant mortality and dieback or are shifts dependent on differences among species, soils, land use and plant demography?

Location: Texas Agrilife Research Station, Sonora, Texas, USA (30.1° N 100.3° W).

Methods: Following an exceptional drought from 1951 to 1957, a study was conducted to quantify rates of mortality for various woody plant species. In 2011, we repeated this study within three long-term …