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Full-Text Articles in Life Sciences

Forest Ecosystems Of Temperate Climatic Regions: From Ancient Use To Climate Change, Frank S. Gilliam Dec 2016

Forest Ecosystems Of Temperate Climatic Regions: From Ancient Use To Climate Change, Frank S. Gilliam

Biological Sciences Faculty Research

Humans have long utilized resources from all forest biomes, but the most indelible anthropogenic signature has been the expanse of human populations in temperate forests. The purpose of this review is to bring into focus the diverse forests of the temperate region of the biosphere, including those of hardwood, conifer and mixed dominance, with a particular emphasis on crucial challenges for the future of these forested areas. Implicit in the term ‘temperate’ is that the predominant climate of these forest regions has distinct cyclic, seasonal changes involving periods of growth and dormancy. The specific temporal patterns of seasonal change, however, …


Agricultural Trade Publications And The 2012 Midwestern U.S. Drought: A Missed Opportunity For Climate Risk Communication, Sarah P. Church, Tonya Haigh, Melissa Widhalm, Silvestre Garcia De Jalon, Nicholas Babin, Stuart Carlton, Michael Dunn, Katie Fagan, Cody L. Knutson, Linda Stalker Prokopy Nov 2016

Agricultural Trade Publications And The 2012 Midwestern U.S. Drought: A Missed Opportunity For Climate Risk Communication, Sarah P. Church, Tonya Haigh, Melissa Widhalm, Silvestre Garcia De Jalon, Nicholas Babin, Stuart Carlton, Michael Dunn, Katie Fagan, Cody L. Knutson, Linda Stalker Prokopy

Department of Forestry & Natural Resources Faculty Publications

The Midwestern United States experienced a devastating drought in 2012, leading to reduced corn and soybean yields and increased instances of pests and disease. Climate change induced weather variability and extremes are expected to increase in the future, and have and will continue to impact the agricultural sector. This study investigated how agricultural trade publications portrayed the 2012 U.S. Midwestern drought, whether climate change was associated with drought, and whether these publications laid out transformative adaptation measures farmers could undertake in order to increase their adaptive capacity for future climate uncertainty. We performed a content analysis of 1000 media reports …


Useful To Usable: Developing Usable Climate Science For Agriculture, Linda S. Prokopy, J Stuart Carlton, Tonya Haigh, Maria Carmen Lemos, Amber Saylor Mase, Melissa Widhalm Oct 2016

Useful To Usable: Developing Usable Climate Science For Agriculture, Linda S. Prokopy, J Stuart Carlton, Tonya Haigh, Maria Carmen Lemos, Amber Saylor Mase, Melissa Widhalm

Department of Forestry & Natural Resources Faculty Publications

The Useful to Usable (U2U) project was a six-year research and extension project funded by the United States Department of Agriculture to provide both useful and usable climate information for the agricultural (corn) sector in the Midwestern United States. The project adopted an extensive co-production of knowledge and decision-making approach that involved intense iteration with potential end-users, including farmers and a variety of pro- fessional agricultural advisors, through focus groups and surveys, feedback at outreach events, and frequent informal interactions to develop both decision support tools and delivery mechanisms that met stakeholder needs. This overview paper for this special issue …


Modeling Historical And Future Range Of Variability Scenarios In The Yuba River Watershed, Tahoe National Forest, California, Maritza Mallek Jul 2016

Modeling Historical And Future Range Of Variability Scenarios In The Yuba River Watershed, Tahoe National Forest, California, Maritza Mallek

Masters Theses

In California's northern Sierra Nevada mountains, the fire-dependent processes of forest ecosystems have been interrupted and altered by human land use and fire suppression. U.S. Forest Service policy directs land managers to plan for a future that includes multiple use and the restoration of resilient ecosystems. Planning decisions are to be informed by an analysis of the range of variability of ecological processes at multiple scales. Current climate trends in the northern Sierra are of increasing temperatures, increased precipitation, and earlier snowmelt, as well as changes to the frequency and duration of drought. These climate changes have and continue to …


A Multiple‐Scale Assessment Of Long‐Term Aspen Persistence And Elevational Range Shifts In The Colorado Front Range, Mario Bretfeld, Scott B. Franklin, Robert K. Peet May 2016

A Multiple‐Scale Assessment Of Long‐Term Aspen Persistence And Elevational Range Shifts In The Colorado Front Range, Mario Bretfeld, Scott B. Franklin, Robert K. Peet

Aspen Bibliography

Aspen forests and woodlands are some of the most species‐rich forest communities in the northern hemisphere. Changing climate, altered disturbance regimes, land use, and increased herbivore pressure threaten these forests both in Eurasia and North America. In addition, rapid mortality dubbed “Sudden Aspen Decline” is a concern for aspen's long‐term presence in the western United States, especially Colorado and Utah. Yet it is still unclear whether aspen is persistent or declining at the landscape scale. We assessed aspen persistence at different spatial scales in the Colorado Front Range by resampling 89 plots containing aspen from among 305 vegetation plots sampled …


A Systems Approach To Modelling The Effects Of Climate Change On Agroforestry: A Case Study In Western Tanzania, Elaine M. Samuel May 2016

A Systems Approach To Modelling The Effects Of Climate Change On Agroforestry: A Case Study In Western Tanzania, Elaine M. Samuel

Electronic Thesis and Dissertation Repository

Climate change is anticipated to have significant effects on agricultural production in sub-Saharan Africa as the magnitude of weather events increase in severity. Smallholder farmers in western Tanzania are potentially vulnerable to climate change impact as crops rely on precipitation as the only source of water. It is prudent to evaluate different modes of agricultural adaptations, such as agroforestry, that these farmers can easily adopt to improve their resiliency to the effects of climate change. System dynamics modelling is a cost-effective tool to simulate the long-term behaviour of agroforestry systems under future climate conditions. Water, Nutrient, and Light Capture in …


Short-Term Effects Of Warming Treatment And Precipitation Manipulation On The Ecophysiological Responses Of Pinus Densiflora Seedlings, Soon Jin Yun, Saerom Han, Seung Hyun Han, Seongjun Kim, Guanlin Li, Minji Park, Yowhan Son Jan 2016

Short-Term Effects Of Warming Treatment And Precipitation Manipulation On The Ecophysiological Responses Of Pinus Densiflora Seedlings, Soon Jin Yun, Saerom Han, Seung Hyun Han, Seongjun Kim, Guanlin Li, Minji Park, Yowhan Son

Turkish Journal of Agriculture and Forestry

The aim of this study was to investigate the short-term effects of warming treatment and precipitation manipulation on the growth, photosynthetic rate, and chlorophyll content of Pinus densiflora seedlings based on a climate change scenario in Korea. Two-year-old P. densiflora seedlings were planted in a nursery in April 2013. The air temperature of warmed plots (W) was set to increase by 3 °C compared to control plots (C) using an infrared heater in May 2013. The three precipitation manipulations consisted of decreased precipitation using transparent panels (-30%; P-), increased precipitation using pumps and drip irrigation (+30%; P+), and a control …


Riparian Trees And Aridland Streams Of The Southwestern United States: An Assessment Of The Past, Present, And Future, D. Max Smith, Deborah M. Finch Jan 2016

Riparian Trees And Aridland Streams Of The Southwestern United States: An Assessment Of The Past, Present, And Future, D. Max Smith, Deborah M. Finch

USDA Forest Service / UNL Faculty Publications

Riparian ecosystems are vital components of aridlands within the southwestern United States. Historically, surface flows influenced population dynamics of native riparian trees. Many southwestern streams has been altered by regulation, however, and will be further affected by greenhouse warming. Our analysis of stream gage data revealed that decreases in volume of annual discharge and mean peak discharge and a shift to earlier peak discharge will occur in the Southern Rockies region of Colorado, New Mexico, and Utah. These changes will likely decrease rates of reproduction and survival of cottonwood (Populus fremontii and Populus deltoides ssp. wislizenii), Goodding's willow …


A Forest Vulnerability Index Based On Drought And High Temperatures, David Mildrexler, Zhiqiang Yang, Warren B. Cohen, David M. Bell Jan 2016

A Forest Vulnerability Index Based On Drought And High Temperatures, David Mildrexler, Zhiqiang Yang, Warren B. Cohen, David M. Bell

USDA Forest Service / UNL Faculty Publications

Increasing forest stress and tree mortality has been directly linked to combinations of drought and high temperatures. The climatic changes expected during the next decades – large increases in mean temperature, increased heat waves, and significant long-term regional drying in the western USA – will likely increase chronic forest stress and mortality. The aim of this research is to develop and apply a new forest vulnerability index (FVI) associated with drought and high temperatures across the Pacific Northwest region (PNW; Oregon and Washington) of the USA during the MODIS Aqua era (since 2003). Our technique incorporates the alterations to canopy …


Contributing Factors For Drought In United States Forest Ecosystems Under Projected Future Climates And Their Uncertainty, Charles H. Luce, James M. Vose, Neil Pederson, John Campbell, Connie Millar, Patrick Kormos, Ross Woods Jan 2016

Contributing Factors For Drought In United States Forest Ecosystems Under Projected Future Climates And Their Uncertainty, Charles H. Luce, James M. Vose, Neil Pederson, John Campbell, Connie Millar, Patrick Kormos, Ross Woods

USDA Forest Service / UNL Faculty Publications

Observations of increasing global forest die-off related to drought are leading to more questions about potential increases in drought occurrence, severity, and ecological consequence in the future. Dry soils and warm temperatures interact to affect trees during drought; so understanding shifting risks requires some understanding of changes in both temperature and precipitation. Unfortunately, strong precipitation uncertainties in climate models yield substantial uncertainty in projections of drought occurrence. We argue that disambiguation of drought effects into temperature and precipitation-mediated processes can alleviate some of the implied uncertainty. In particular, the disambiguation can clarify geographic diversity in forest sensitivity to multifarious drivers …


Short-Term Changes Of Leaf Area Index, Light Transmission, And Gap In A Temperate Mixed Deciduous Forest Ecosystem In Bartın, Turkey, İlyas Bolat, Ömer Kara, Meli̇h Öztürk Jan 2016

Short-Term Changes Of Leaf Area Index, Light Transmission, And Gap In A Temperate Mixed Deciduous Forest Ecosystem In Bartın, Turkey, İlyas Bolat, Ömer Kara, Meli̇h Öztürk

Turkish Journal of Agriculture and Forestry

In this study, leaf area index (LAI), light transmission, and gap were estimated by using the hemispherical photograph analysis technique with Hemisfer software version 1.5.3 for a temperate mixed deciduous forest. The height of the overall vegetation in the stand ranged from 15 to 20 m, and the diameters of the trees in the stand at breast height varied between 14 and 28 cm. This study showed that the mean value of LAI increased by 4% in the 5-year period from 2007 to 2012. LAI was significantly (P < 0.05) greater in 2012 than in 2007, whereas the mean percentage of light transmission was significantly lower in 2012 than it was in 2007. In addition, there was a significant (P < 0.01) correlation between LAI and light transmission, and there was also a statistically significant correlation between the gap and light transmission (P < 0.05). According to long-term meteorological data (1982-2012), this study also demonstrated that the mean air temperature rose approximately 1.0 °C between 2007 and 2012. Consequently, this study indicated that LAI varies with respect to time and the increase of LAI leads to a decrease in light transmission. Additionally, the air temperature and precipitation have a significant influence on the LAI.


Fire Severity Controlled Susceptibility To A 1940s Spruce Beetle Outbreak In Colorado, Usa, Dominik Kulakowski, Thomas T. Veblen, Peter Beb Jan 2016

Fire Severity Controlled Susceptibility To A 1940s Spruce Beetle Outbreak In Colorado, Usa, Dominik Kulakowski, Thomas T. Veblen, Peter Beb

Geography

The frequency, magnitude, and size of forest disturbances are increasing globally. Much recent research has focused on how the occurrence of one disturbance may affect susceptibility to subsequent disturbances. While much has been learned about such linked disturbances, the strength of the interactions is likely to be contingent on the severity of disturbances as well as climatic conditions, both of which can affect disturbance intensity and tree resistance to disturbances. Subalpine forests in western Colorado were affected by extensive and severe wildfires in the late 19th century and an extensive and severe outbreak of spruce beetle (Dendroctonus rufipennis) in the …


Not Only Climate: Interacting Drivers Of Treeline Change In Europe, Dominik Kulakowski, Ignacio Barbeito, Alejandro Casteller, Ryszard J. Kaczka, Peter Bebi Jan 2016

Not Only Climate: Interacting Drivers Of Treeline Change In Europe, Dominik Kulakowski, Ignacio Barbeito, Alejandro Casteller, Ryszard J. Kaczka, Peter Bebi

Geography

Treelines have long been recognized as important ecotones and likely harbingers of climate change. However, over the last century many treelines have been affected not only by global warming, but also by the interactions of climate, forest disturbance and the consequences of abrupt demographic and economic changes. Recent research has increasingly stressed how multiple ecological, biophysical, and human factors interact to shape ecological dynamics. Here we highlight the need to consider interactions among multiple drivers to more completely understand and predict treeline dynamics in Europe.