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Jason C. Neff
The Environmental Studies Program, University of Colorado at Boulder, Boulder, CO 80309, USA

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Journal article
Published: 24 April 2021 in Land
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Smallholder agriculture is a major source of income and food for developing nations. With more frequent drought and increasing scarcity of arable land, more accurate land-use planning tools are needed to allocate land resources to support regional agricultural activity. To address this need, we created Land Capability Classification (LCC) system maps using data from two digital soil maps, which were compared with measurements from 1305 field sites in the Dosso region of Niger. Based on these, we developed 250 m gridded maps of LCC values across the region. Across the region, land is severely limited for agricultural use because of low available water-holding capacity (AWC) that limits dry season agricultural potential, especially without irrigation, and requires more frequent irrigation where supplemental water is available. If the AWC limitation is removed in the LCC algorithm (i.e., simulating the use of sufficient irrigation or a much higher and more evenly distributed rainfall), the dominant limitations become less severe and more spatially varied. Finally, we used additional soil fertility data from the field samples to illustrate the value of collecting contemporary data for dynamic soil properties that are critical for crop production, including soil organic carbon, phosphorus and nitrogen.

ACS Style

Tara Ippolito; Jeffrey Herrick; Ekwe Dossa; Maman Garba; Mamadou Ouattara; Upendra Singh; Zachary Stewart; P. Prasad; Idrissa Oumarou; Jason Neff. A Comparison of Approaches to Regional Land-Use Capability Analysis for Agricultural Land-Planning. Land 2021, 10, 458 .

AMA Style

Tara Ippolito, Jeffrey Herrick, Ekwe Dossa, Maman Garba, Mamadou Ouattara, Upendra Singh, Zachary Stewart, P. Prasad, Idrissa Oumarou, Jason Neff. A Comparison of Approaches to Regional Land-Use Capability Analysis for Agricultural Land-Planning. Land. 2021; 10 (5):458.

Chicago/Turabian Style

Tara Ippolito; Jeffrey Herrick; Ekwe Dossa; Maman Garba; Mamadou Ouattara; Upendra Singh; Zachary Stewart; P. Prasad; Idrissa Oumarou; Jason Neff. 2021. "A Comparison of Approaches to Regional Land-Use Capability Analysis for Agricultural Land-Planning." Land 10, no. 5: 458.

Journal article
Published: 12 February 2021 in Earth's Future
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The United States is a world leader in the production of maize and other crops and the agricultural success of the country is directly linked to the intensive use of fertilizers and irrigation. However, even in advanced agricultural systems, soils can become degraded over time due to factors such as soil organic matter loss and erosion. Here, we use a series of scenario‐based model analyses to show that about one third of current annual U.S. N fertilizer use in maize agriculture is used to compensate for the long‐term loss of soil fertility through erosion and organic matter loss. This leads to over a half billion dollars per year in extra fertilizer supply costs to U.S. farmers. These results highlight the potential to reduce both the input costs and environmental impacts of agriculture through the restoration of soil organic matter in agricultural soils.This article is protected by copyright. All rights reserved.

ACS Style

W. S. Jang; J. C. Neff; Y. Im; L. Doro; J. E. Herrick. The Hidden Costs of Land Degradation in US Maize Agriculture. Earth's Future 2021, 9, 1 .

AMA Style

W. S. Jang, J. C. Neff, Y. Im, L. Doro, J. E. Herrick. The Hidden Costs of Land Degradation in US Maize Agriculture. Earth's Future. 2021; 9 (2):1.

Chicago/Turabian Style

W. S. Jang; J. C. Neff; Y. Im; L. Doro; J. E. Herrick. 2021. "The Hidden Costs of Land Degradation in US Maize Agriculture." Earth's Future 9, no. 2: 1.

Journal article
Published: 21 November 2020 in Journal of Geophysical Research: Biogeosciences
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Acid deposition associated with precipitation is an ecological problem that has affected watersheds in industrialized parts of North America and Europe, but remote landscapes, such as the Colorado Rocky Mountains, have also been impacted. The deposition of strong acids, including nitric and sulfuric acids, has decreased substantially over the past 30 years at Niwot Ridge, a high‐alpine watershed of Colorado. The pH of precipitation has followed these declines and has increased to ~5.5. Meanwhile, NH4+, another important constituent of acid/base balance, and a fertilizing nutrient, has more than doubled in precipitation between 1984 and 2017. A statistical model of long‐term water chemistry concentrations and loads revealed a variety of trends in watershed export of acids and bases, some of which were unexpected, and remain unexplained. For example, despite declining sulfate deposition, sulfate export has increased. On the other hand, watershed nitrate export has remained constant despite decreases in atmospheric deposition, while watershed NH4+ export has increased, albeit minimally, relative to total nitrogen export. Watershed pH and alkalinity appear to have stabilized in response to decreased acid precipitation, which may be explained by geochemical processes, such as carbonate weathering. Overall, in this high‐alpine watershed, atmospheric deposition is trending toward preindustrial conditions, and there is a need to conduct targeted, process‐based studies to determine the mechanisms underlying these trends. The unexpected watershed responses that we identify here require a new framework for understanding acid precipitation recovery.

ACS Style

John T. Crawford; Eve‐Lyn S. Hinckley; Jason C. Neff. Long‐Term Trends in Acid Precipitation and Watershed Elemental Export From an Alpine Catchment of the Colorado Rocky Mountains, USA. Journal of Geophysical Research: Biogeosciences 2020, 125, 1 .

AMA Style

John T. Crawford, Eve‐Lyn S. Hinckley, Jason C. Neff. Long‐Term Trends in Acid Precipitation and Watershed Elemental Export From an Alpine Catchment of the Colorado Rocky Mountains, USA. Journal of Geophysical Research: Biogeosciences. 2020; 125 (11):1.

Chicago/Turabian Style

John T. Crawford; Eve‐Lyn S. Hinckley; Jason C. Neff. 2020. "Long‐Term Trends in Acid Precipitation and Watershed Elemental Export From an Alpine Catchment of the Colorado Rocky Mountains, USA." Journal of Geophysical Research: Biogeosciences 125, no. 11: 1.

Journal article
Published: 16 December 2019 in Sustainability
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The South Korean government has recently focused on environmental protection efforts to improve water quality which has been degraded by nonpoint sources of water pollution from runoff. In order to take care of environmental issues, many physically-based models have been used. However, the physically-based models take a large amount of work to carry out site simulations, and there is a need to find faster and more efficient approaches. For an alternative approach for sediment management using the physically-based models, the machine learning-based models were used for estimating sediment trapping efficiency of vegetative filter strips. The seven nonlinear regression algorithms of machine learning models (e.g., decision tree, multilayer perceptron, k-nearest neighbors, support vector machine, random forest, AdaBoost and gradient boosting) were applied to select the model which best estimates the sediment trapping efficiency of vegetative filter strips. The sediment trapping efficiencies calculated by the machine learning models showed similar results as those of vegetative filter strip modeling system (VFSMOD-W) model. As a result of the accuracy evaluation among the seven machine learning models, the multilayer perceptron model-derived the best fit with VFSMOD-W model. It is expected that the sediment trapping efficiency of the vegetative filter strips in various cases in agricultural fields in South Korea can be predicted easier, faster and accurately by the machine learning models developed in this study. Machine learning models can be used to evaluate sediment trapping efficiency without complicated physically-based model design and high computational cost. Therefore, decision makers can maximize the quality of their outputs by minimizing their efforts in the decision-making process.

ACS Style

Joo Hyun Bae; Jeongho Han; Dongjun Lee; Jae E Yang; Jonggun Kim; Kyoung Jae Lim; Jason C Neff; Won Seok Jang. Evaluation of Sediment Trapping Efficiency of Vegetative Filter Strips Using Machine Learning Models. Sustainability 2019, 11, 7212 .

AMA Style

Joo Hyun Bae, Jeongho Han, Dongjun Lee, Jae E Yang, Jonggun Kim, Kyoung Jae Lim, Jason C Neff, Won Seok Jang. Evaluation of Sediment Trapping Efficiency of Vegetative Filter Strips Using Machine Learning Models. Sustainability. 2019; 11 (24):7212.

Chicago/Turabian Style

Joo Hyun Bae; Jeongho Han; Dongjun Lee; Jae E Yang; Jonggun Kim; Kyoung Jae Lim; Jason C Neff; Won Seok Jang. 2019. "Evaluation of Sediment Trapping Efficiency of Vegetative Filter Strips Using Machine Learning Models." Sustainability 11, no. 24: 7212.

Journal article
Published: 06 May 2019 in Journal of Geophysical Research: Biogeosciences
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Mineral aerosols (dust) generated in the dryland regions of Australia have the potential to reach New Zealand through atmospheric transport. Although a large portion of dust in New Zealand originates in Australia, little is known about how dust deposition has varied over time in New Zealand or what may have caused this variation. We used geochemical dust proxies to examine the recent history of dust deposition to two alpine lakes in Kahurangi National Park, South Island, New Zealand. Geochemical indicators suggest that dust deposition began to increase around 1900, with the greatest deposition rates occurring from ~1920 to ~1990. In subsequent decades dust deposition rates to New Zealand lakes appear to have declined. This rise and fall of dust deposition recorded in New Zealand lakes is consistent with dust records from the Antarctic Ice Sheet, Eastern Australia, and incidents of low visibility due to dust events recorded at Australian climate stations. The dust deposition rate over time also follows the temporal pattern of land use in south and central Australia over the time scale of the 20th‐century suggesting a causal linkage. It is possible, and perhaps likely, that drought cycles also affected both emissions and transport pathways but over shorter time periods this was difficult to discern at the temporal resolution of these lake sediment cores. The increase in dust deposition to the high elevation regions of New Zealand likely has implications for the biogeochemistry of alpine lakes in the Tasman Mountains.

ACS Style

Janice Brahney; Ashley P. Ballantyne; Marcus Vandergoes; Troy Baisden; Jason C. Neff. Increased Dust Deposition in New Zealand Related to Twentieth Century Australian Land Use. Journal of Geophysical Research: Biogeosciences 2019, 124, 1181 -1193.

AMA Style

Janice Brahney, Ashley P. Ballantyne, Marcus Vandergoes, Troy Baisden, Jason C. Neff. Increased Dust Deposition in New Zealand Related to Twentieth Century Australian Land Use. Journal of Geophysical Research: Biogeosciences. 2019; 124 (5):1181-1193.

Chicago/Turabian Style

Janice Brahney; Ashley P. Ballantyne; Marcus Vandergoes; Troy Baisden; Jason C. Neff. 2019. "Increased Dust Deposition in New Zealand Related to Twentieth Century Australian Land Use." Journal of Geophysical Research: Biogeosciences 124, no. 5: 1181-1193.

Journal article
Published: 04 January 2017 in Ecosphere
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ACS Style

Xuyang Lu; Katharine Kelsey; Yan Yan; Jian Sun; Xiaodan Wang; Genwei Cheng; Jason C. Neff. Effects of grazing on ecosystem structure and function of alpine grasslands in Qinghai-Tibetan Plateau: a synthesis. Ecosphere 2017, 8, e01656 .

AMA Style

Xuyang Lu, Katharine Kelsey, Yan Yan, Jian Sun, Xiaodan Wang, Genwei Cheng, Jason C. Neff. Effects of grazing on ecosystem structure and function of alpine grasslands in Qinghai-Tibetan Plateau: a synthesis. Ecosphere. 2017; 8 (1):e01656.

Chicago/Turabian Style

Xuyang Lu; Katharine Kelsey; Yan Yan; Jian Sun; Xiaodan Wang; Genwei Cheng; Jason C. Neff. 2017. "Effects of grazing on ecosystem structure and function of alpine grasslands in Qinghai-Tibetan Plateau: a synthesis." Ecosphere 8, no. 1: e01656.

Journal article
Published: 07 June 2016 in Environmental Management
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Federal lands in the United States have been identified as important areas where forests could be managed to enhance carbon storage and help mitigate climate change. However, there has been little work examining the context for decision making for carbon in a multiple-use public land environment, and how science can support decision making. This case study of the San Juan National Forest and the Bureau of Land Management Tres Rios Field Office in southwestern Colorado examines whether land managers in these offices have adequate tools, information, and management flexibility to practice effective carbon stewardship. To understand how carbon was distributed on the management landscape we added a newly developed carbon map for the SJNF–TRFO area based on Landsat TM texture information (Kelsey and Neff in Remote Sens 6:6407–6422. doi:10.​3390/​rs6076407, 2014). We estimate that only about 22 % of the aboveground carbon in the SJNF–TRFO is in areas designated for active management, whereas about 38 % is in areas with limited management opportunities, and 29 % is in areas where natural processes should dominate. To project the effects of forest management actions on carbon storage, staff of the SJNF are expected to use the Forest Vegetation Simulator (FVS) and extensions. While identifying FVS as the best tool generally available for this purpose, the users and developers we interviewed highlighted the limitations of applying an empirically based model over long time horizons. Future research to improve information on carbon storage should focus on locations and types of vegetation where carbon management is feasible and aligns with other management priorities.

ACS Style

Lisa Dilling; Katharine C. Kelsey; Daniel P. Fernandez; Yin D. Huang; Jana B. Milford; Jason C. Neff. Managing Carbon on Federal Public Lands: Opportunities and Challenges in Southwestern Colorado. Environmental Management 2016, 58, 283 -296.

AMA Style

Lisa Dilling, Katharine C. Kelsey, Daniel P. Fernandez, Yin D. Huang, Jana B. Milford, Jason C. Neff. Managing Carbon on Federal Public Lands: Opportunities and Challenges in Southwestern Colorado. Environmental Management. 2016; 58 (2):283-296.

Chicago/Turabian Style

Lisa Dilling; Katharine C. Kelsey; Daniel P. Fernandez; Yin D. Huang; Jana B. Milford; Jason C. Neff. 2016. "Managing Carbon on Federal Public Lands: Opportunities and Challenges in Southwestern Colorado." Environmental Management 58, no. 2: 283-296.

Article
Published: 01 March 2016 in Ecosystem Health and Sustainability
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Massive investments in climate change mitigation and adaptation are projected during coming decades. Many of these investments will seek to modify how land is managed. The return on both types of investments can be increased through an understanding of land potential: the potential of the land to support primary production and ecosystem services, and its resilience. A Land-Potential Knowledge System (LandPKS) is being developed and implemented to provide individual users with point-based estimates of land potential based on the integration of simple, geo-tagged user inputs with cloud-based information and knowledge. This system will rely on mobile phones for knowledge and information exchange, and use cloud computing to integrate, interpret, and access relevant knowledge and information, including local knowledge about land with similar potential. The system will initially provide management options based on long-term land potential, which depends on climate, topography, and relatively static soil properties, such as soil texture, depth, and mineralogy. Future modules will provide more specific management information based on the status of relatively dynamic soil properties such as organic matter and nutrient content, and of weather. The paper includes a discussion of how this system can be used to help distinguish between meteorological and edaphic drought.

ACS Style

Jeffrey E. Herrick; Ioana Bouvier; Marina Coetzee; Emile Elias; Jason W. Karl; Hanspeter Liniger; John Matuszak; Lilian Wangui Ndungu; Michael Obersteiner; Keith D. Shepherd; Rik Bosch; Adam Beh; Edmundo Barrios; David Dent; Tomislav Hengl; Jason C. Neff; Kevin C. Urama; Nicholas P. Webb. The land?potential knowledge system (landpks): mobile apps and collaboration for optimizing climate change investments. Ecosystem Health and Sustainability 2016, 2, 1 .

AMA Style

Jeffrey E. Herrick, Ioana Bouvier, Marina Coetzee, Emile Elias, Jason W. Karl, Hanspeter Liniger, John Matuszak, Lilian Wangui Ndungu, Michael Obersteiner, Keith D. Shepherd, Rik Bosch, Adam Beh, Edmundo Barrios, David Dent, Tomislav Hengl, Jason C. Neff, Kevin C. Urama, Nicholas P. Webb. The land?potential knowledge system (landpks): mobile apps and collaboration for optimizing climate change investments. Ecosystem Health and Sustainability. 2016; 2 (3):1.

Chicago/Turabian Style

Jeffrey E. Herrick; Ioana Bouvier; Marina Coetzee; Emile Elias; Jason W. Karl; Hanspeter Liniger; John Matuszak; Lilian Wangui Ndungu; Michael Obersteiner; Keith D. Shepherd; Rik Bosch; Adam Beh; Edmundo Barrios; David Dent; Tomislav Hengl; Jason C. Neff; Kevin C. Urama; Nicholas P. Webb. 2016. "The land?potential knowledge system (landpks): mobile apps and collaboration for optimizing climate change investments." Ecosystem Health and Sustainability 2, no. 3: 1.

Journal article
Published: 17 February 2016 in BioScience
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An increasing number of network observatories have been established globally to collect long-term biogeochemical data at multiple spatial and temporal scales. Although many outstanding questions in biogeochemistry would benefit from network science, the ability of the earth- and environmental-sciences community to conduct synthesis studies within and across networks is limited and seldom done satisfactorily. We identify the ideal characteristics of networks, common problems with using data, and key improvements to strengthen intra- and internetwork compatibility. We suggest that targeted improvements to existing networks should include promoting standardization in data collection, developing incentives to promote rapid data release to the public, and increasing the ability of investigators to conduct their own studies across sites. Internetwork efforts should include identifying a standard measurement suite—we propose profiles of plant canopy and soil properties—and an online, searchable data portal that connects network, investigator-led, and citizen-science projects.

ACS Style

Eve-Lyn S. Hinckley; Suzanne P. Anderson; Jill S. Baron; Peter D. Blanken; Gordon B. Bonan; William D. Bowman; Sarah Elmendorf; Noah Fierer; Andrew M. Fox; Keli J. Goodman; Katherine D. Jones; Danica L. Lombardozzi; Claire K. Lunch; Jason C. Neff; Michael D. SanClements; Katharine N. Suding; William R. Wieder. Optimizing Available Network Resources to Address Questions in Environmental Biogeochemistry. BioScience 2016, 66, 317 -326.

AMA Style

Eve-Lyn S. Hinckley, Suzanne P. Anderson, Jill S. Baron, Peter D. Blanken, Gordon B. Bonan, William D. Bowman, Sarah Elmendorf, Noah Fierer, Andrew M. Fox, Keli J. Goodman, Katherine D. Jones, Danica L. Lombardozzi, Claire K. Lunch, Jason C. Neff, Michael D. SanClements, Katharine N. Suding, William R. Wieder. Optimizing Available Network Resources to Address Questions in Environmental Biogeochemistry. BioScience. 2016; 66 (4):317-326.

Chicago/Turabian Style

Eve-Lyn S. Hinckley; Suzanne P. Anderson; Jill S. Baron; Peter D. Blanken; Gordon B. Bonan; William D. Bowman; Sarah Elmendorf; Noah Fierer; Andrew M. Fox; Keli J. Goodman; Katherine D. Jones; Danica L. Lombardozzi; Claire K. Lunch; Jason C. Neff; Michael D. SanClements; Katharine N. Suding; William R. Wieder. 2016. "Optimizing Available Network Resources to Address Questions in Environmental Biogeochemistry." BioScience 66, no. 4: 317-326.

Journal article
Published: 01 January 2015 in Agricultural and Forest Meteorology
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ACS Style

Zhaosheng Fan; Jason C. Neff; Niall Hanan. Modeling pulsed soil respiration in an African savanna ecosystem. Agricultural and Forest Meteorology 2015, 200, 282 -292.

AMA Style

Zhaosheng Fan, Jason C. Neff, Niall Hanan. Modeling pulsed soil respiration in an African savanna ecosystem. Agricultural and Forest Meteorology. 2015; 200 ():282-292.

Chicago/Turabian Style

Zhaosheng Fan; Jason C. Neff; Niall Hanan. 2015. "Modeling pulsed soil respiration in an African savanna ecosystem." Agricultural and Forest Meteorology 200, no. : 282-292.

Journal article
Published: 01 December 2014 in Aeolian Research
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Aeolian dust can influence nutrient availability, soil fertility, plant interactions, and water-holding capacity in both source and downwind environments. A network of 85 passive collectors for aeolian sediment spanning numerous plant communities, soil types, and land-use histories covering approximately 4000 square kilometers across southeastern Utah was used to sample horizontal emissions of aeolian sediment. The sample archive dates to 2004 and is currently the largest known record of field-scale dust emissions for the southwestern United States. Sediment flux peaked during the spring months in all plant communities (mean: 38.1gm−2d−1), related to higher, sustained wind speeds that begin in the early spring. Dust flux was lowest during the winter period (mean: 5gm−2d−1) when surface wind speeds are typically low. Sites dominated by blackbrush and sagebrush shrubs had higher sediment flux (mean: 19.4gm−2d−1) compared to grasslands (mean: 11.2gm−2d−1), saltbush shrublands (mean: 10.3gm−2d−1), and woodlands (mean: 8.1gm−2d−1). Contrary to other studies on dust emissions, antecedent precipitation during one, two, and three seasons prior to sample collection did not significantly influence emission rates. Physical site-scale factors controlling dust emissions were complex and varied from one vegetation type to another

ACS Style

Cody B. Flagg; Jason Neff; Richard L. Reynolds; Jayne Belnap. Spatial and temporal patterns of dust emissions (2004–2012) in semi-arid landscapes, southeastern Utah, USA. Aeolian Research 2014, 15, 31 -43.

AMA Style

Cody B. Flagg, Jason Neff, Richard L. Reynolds, Jayne Belnap. Spatial and temporal patterns of dust emissions (2004–2012) in semi-arid landscapes, southeastern Utah, USA. Aeolian Research. 2014; 15 ():31-43.

Chicago/Turabian Style

Cody B. Flagg; Jason Neff; Richard L. Reynolds; Jayne Belnap. 2014. "Spatial and temporal patterns of dust emissions (2004–2012) in semi-arid landscapes, southeastern Utah, USA." Aeolian Research 15, no. : 31-43.

Journal article
Published: 03 September 2014 in Carbon Balance and Management
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Forests store large amounts of carbon in forest biomass, and this carbon can be released to the atmosphere following forest disturbance or management. In the western US, forest fuel reduction treatments designed to reduce the risk of high severity wildfire can change forest carbon balance by removing carbon in the form of biomass, and by altering future potential wildfire behavior in the treated stand. Forest treatment carbon balance is further affected by the fate of this biomass removed from the forest, and the occurrence and intensity of a future wildfire in this stand. In this study we investigate the carbon balance of a forest treatment with varying fates of harvested biomass, including use for bioenergy electricity production, and under varying scenarios of future disturbance and regeneration.

ACS Style

Katharine C Kelsey; Kallie L Barnes; Michael G Ryan; Jason C Neff. Short and long-term carbon balance of bioenergy electricity production fueled by forest treatments. Carbon Balance and Management 2014, 9, 6 -6.

AMA Style

Katharine C Kelsey, Kallie L Barnes, Michael G Ryan, Jason C Neff. Short and long-term carbon balance of bioenergy electricity production fueled by forest treatments. Carbon Balance and Management. 2014; 9 (1):6-6.

Chicago/Turabian Style

Katharine C Kelsey; Kallie L Barnes; Michael G Ryan; Jason C Neff. 2014. "Short and long-term carbon balance of bioenergy electricity production fueled by forest treatments." Carbon Balance and Management 9, no. 1: 6-6.

Journal article
Published: 09 July 2014 in Remote Sensing
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Maps of forest biomass are important tools for managing natural resources and reporting terrestrial carbon stocks. Using the San Juan National Forest in Southwest Colorado as a case study, we evaluate regional biomass maps created using physical variables, spectral vegetation indices, and image textural analysis on Landsat TM imagery. We investigate eight gray level co-occurrence matrix based texture measures (mean, variance, homogeneity, contrast, dissimilarity, entropy, second moment and correlation) on four window sizes (3 × 3, 5 × 5, 7 × 7, 9 × 9) at four offsets ([1,0], [1,1], [0,1], [1,−1]) on four Landsat TM bands (2, 3, 4, and 5). The map with the highest prediction quality was created using three texture metrics calculated from Landsat Band 2 on a 3 × 3 window and an offset of [0,1]: entropy, mean and correlation; and one physical variable: slope. The correlation of predicted versus observed biomass values for our texture-based biomass map is r = 0.86, the Root Mean Square Error is 45.6 Mg∙ha−1, and the Coefficient of Variation of the Root Mean Square Error is 0.31. We find that models including image texture variables are more strongly correlated with biomass than models using only physical and spectral variables. Additionally, we suggest that the use of texture appears to better capture the magnitude and direction of biomass change following disturbance compared to spectral approaches. The biomass mapping methods we present here are widely applicable throughout the US, as they are based on publically available datasets and utilize relatively simple analytical routines.

ACS Style

Katharine C. Kelsey; Jason C. Neff. Estimates of Aboveground Biomass from Texture Analysis of Landsat Imagery. Remote Sensing 2014, 6, 6407 -6422.

AMA Style

Katharine C. Kelsey, Jason C. Neff. Estimates of Aboveground Biomass from Texture Analysis of Landsat Imagery. Remote Sensing. 2014; 6 (7):6407-6422.

Chicago/Turabian Style

Katharine C. Kelsey; Jason C. Neff. 2014. "Estimates of Aboveground Biomass from Texture Analysis of Landsat Imagery." Remote Sensing 6, no. 7: 6407-6422.

Journal article
Published: 21 May 2014 in Biogeochemistry
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Alpine lakes receive a large fraction of their nutrients from atmospheric sources and are consequently sensitive to variations in both the amount and chemistry of atmospheric deposition. In this study we explored the spatial changes in lake water chemistry and biology along a gradient of dust deposition in the Wind River Range, Wyoming. Regional differences were explored using the variation in bulk deposition, lake water, sediment, and bedrock geochemistry and catchment characteristics. Dust deposition rates in the Southwestern region averaged 3.34 g m−2 year−1, approximately three times higher than deposition rates in the Northwestern region (average 1.06 g m−2 year−1). Dust-P deposition rates ranged from 87 µg P m2 day−1 in the Northwestern region to 276 µg P m2 day−1 in the Southwestern region. Subalpine and alpine lakes in the Southwestern region had greater total phosphorus (TP) concentrations (5–13 µg L−1) and greater sediment phosphorus (SP) concentrations (2–5 mg g−1) than similar lakes elsewhere in the region (1–8 µg L−1 TP, 0.5–2 mg g−1 SP). Lake phosphorus concentrations were related to dissolved organic carbon (DOC) across vegetation gradients, but related to the percent of bare rock, catchment area to lake area, and catchment steepness across dust deposition gradients. Modern phytoplankton and zooplankton biomasses were two orders of magnitude greater in the Southwest than in the Northwest, and alpine lakes in the Southwest had a unique diatom species assemblage with relatively higher concentrations of Asterionella formosa, Pseudostaurosira pseudoconstruens, and Pseudostaurosira brevistriata. These results suggests that catchment controls on P export to lakes (i.e. DOC) are overridden in dominantly bare rock basins where poor soils cannot effectively retain dust deposited P.

ACS Style

J. Brahney; A. P. Ballantyne; P. Kociolek; S. Spaulding; M. Otu; T. Porwoll; Jason Neff. Dust mediated transfer of phosphorus to alpine lake ecosystems of the Wind River Range, Wyoming, USA. Biogeochemistry 2014, 120, 259 -278.

AMA Style

J. Brahney, A. P. Ballantyne, P. Kociolek, S. Spaulding, M. Otu, T. Porwoll, Jason Neff. Dust mediated transfer of phosphorus to alpine lake ecosystems of the Wind River Range, Wyoming, USA. Biogeochemistry. 2014; 120 (1-3):259-278.

Chicago/Turabian Style

J. Brahney; A. P. Ballantyne; P. Kociolek; S. Spaulding; M. Otu; T. Porwoll; Jason Neff. 2014. "Dust mediated transfer of phosphorus to alpine lake ecosystems of the Wind River Range, Wyoming, USA." Biogeochemistry 120, no. 1-3: 259-278.

Journal article
Published: 01 December 2013 in Atmospheric Environment
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ACS Style

Justine M. Nyaga; Michael D. Cramer; Jason C. Neff. Atmospheric nutrient deposition to the west coast of South Africa. Atmospheric Environment 2013, 81, 625 -632.

AMA Style

Justine M. Nyaga, Michael D. Cramer, Jason C. Neff. Atmospheric nutrient deposition to the west coast of South Africa. Atmospheric Environment. 2013; 81 ():625-632.

Chicago/Turabian Style

Justine M. Nyaga; Michael D. Cramer; Jason C. Neff. 2013. "Atmospheric nutrient deposition to the west coast of South Africa." Atmospheric Environment 81, no. : 625-632.

Journal article
Published: 10 October 2013 in Journal of Geophysical Research: Atmospheres
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ACS Style

J. C. Neff; R. L. Reynolds; S. M. Munson; D. Fernandez; J. Belnap. The role of dust storms in total atmospheric particle concentrations at two sites in the western U.S. Journal of Geophysical Research: Atmospheres 2013, 118, 11,201 -11,212.

AMA Style

J. C. Neff, R. L. Reynolds, S. M. Munson, D. Fernandez, J. Belnap. The role of dust storms in total atmospheric particle concentrations at two sites in the western U.S. Journal of Geophysical Research: Atmospheres. 2013; 118 (19):11,201-11,212.

Chicago/Turabian Style

J. C. Neff; R. L. Reynolds; S. M. Munson; D. Fernandez; J. Belnap. 2013. "The role of dust storms in total atmospheric particle concentrations at two sites in the western U.S." Journal of Geophysical Research: Atmospheres 118, no. 19: 11,201-11,212.

Journal article
Published: 05 September 2013 in Carbon Balance and Management
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Increases in the spatial extent and density of woody plants relative to herbaceous species have been observed across many ecosystems. These changes can have large effects on ecosystem carbon stocks and therefore are of interest for regional and national carbon inventories and for potential carbon sequestration or management activities. However, it is challenging to estimate the effect of woody plant encroachment on carbon because aboveground carbon stocks are very heterogeneous spatially and belowground carbon stocks exhibit complex and variable responses to changing plant cover. As a result, estimates of carbon stock changes with woody plant cover remain highly uncertain. In this study, we use a combination of plot- and remote sensing-based techniques to estimate the carbon impacts of piñon and juniper (PJ) encroachment in SE Utah across a variety of spatial scales with a specific focus on the role of spatial heterogeneity in carbon estimates. At a plot scale (300 m2) areas piñon juniper (PJ) encroached areas had 0.26 kg C m-2 less understory vegetation carbon compared to un-encroached sites. This lower amount of carbon was offset by an average of 1.82 kg C m-2 higher carbon in PJ vegetation and 0.50 kg m-2 of C in PJ surface-litter carbon. Soil mineral carbon stocks were unaffected by woody plant cover and density. Aboveground carbon stocks were highly dependent on PJ vegetation density. At a 300 m2 plot-scale, plots with low and high density of PJ forest had 1.40 kg C m-2 and 3.69 kg m-2 more carbon than the un-encroached plot. To examine how these 300 m2 variations influence landscape scale C estimates, historical and contemporary aerial photos were analyzed to develop forest density maps in order to estimate above ground PJ associated C stock changes in a 25 ha area. This technique yielded an average estimate of 1.43 kg m-2 of C accumulation with PJ encroachment. Combining this estimate with analysis of tree growth increments from dendrochronologies, we estimate that these PJ stands are accumulating aboveground C at an annual rate of 0.02 kg C m-2 with no slowing of this rate in healthy PJ. This result is in contrast to what has been observed in large areas of drought related PJ mortality, where C accumulation has ceased. These results illustrate that the encroachment of PJ forests in SE Utah over the last century has resulted in a large (and ongoing) accumulation of carbon in PJ trees and surface litter. However, the magnitude of the increase depends to on the density of vegetation across the landscape and the health of forest stands. Both management activities that remove forest carbon and forest mortality due to drought or wildfire have the potential to quickly reverse the multi-decadal accumulation of carbon in these stands.

ACS Style

Daniel P Fernandez; Jason C Neff; Cho-Ying Huang; Gregory P Asner; Nichole N Barger. Twentieth century carbon stock changes related to Piñon-Juniper expansion into a black sagebrush community. Carbon Balance and Management 2013, 8, 8 -8.

AMA Style

Daniel P Fernandez, Jason C Neff, Cho-Ying Huang, Gregory P Asner, Nichole N Barger. Twentieth century carbon stock changes related to Piñon-Juniper expansion into a black sagebrush community. Carbon Balance and Management. 2013; 8 (1):8-8.

Chicago/Turabian Style

Daniel P Fernandez; Jason C Neff; Cho-Ying Huang; Gregory P Asner; Nichole N Barger. 2013. "Twentieth century carbon stock changes related to Piñon-Juniper expansion into a black sagebrush community." Carbon Balance and Management 8, no. 1: 8-8.

Journal article
Published: 01 September 2013 in Aeolian Research
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Janice Brahney; A.P. Ballantyne; C. Sievers; Jason Neff. Increasing Ca2+ deposition in the western US: The role of mineral aerosols. Aeolian Research 2013, 10, 77 -87.

AMA Style

Janice Brahney, A.P. Ballantyne, C. Sievers, Jason Neff. Increasing Ca2+ deposition in the western US: The role of mineral aerosols. Aeolian Research. 2013; 10 ():77-87.

Chicago/Turabian Style

Janice Brahney; A.P. Ballantyne; C. Sievers; Jason Neff. 2013. "Increasing Ca2+ deposition in the western US: The role of mineral aerosols." Aeolian Research 10, no. : 77-87.

Journal article
Published: 15 June 2013 in Oecologia
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The importance of rock-derived mineral nutrients (P, K, Mn, Mg, and Ca) in plant physiological function is well established. However, one important and relatively unexplored question is whether or not the same rules of plant nutrient use efficiency apply to these essential elements even if they are not limiting to primary production. We examined conifer growth and nutrient use dynamics across sites with contrasting geologies (sedimentary and volcanic) that vary in both rock-derived mineral nutrient and N availability. Differences in bedrock geochemistry generally corresponded to differences in available soil nutrients, such that the volcanic site tended to have greater available nutrients. Foliar nutrient concentrations reflected both differences in bedrock chemistry and indices of available soil nutrients for P, K, and Mn. Aboveground biomass production did not follow expected patterns and was greater for trees growing on low nutrient sites, but only with respect to the annual woody increment. Fine litter production did not differ between sites. Finally, we found evidence for trade-offs between two commonly examined components of nutrient use efficiency (NUE): nutrient productivity (A n) and mean residence time of nutrients. However, we did not find evidence for higher plant NUE in soils with lower nutrient availability for N or rock-derived nutrients.

ACS Style

S. C. Castle; J. C. Neff. What controls plant nutrient use in high elevation ecosystems? Oecologia 2013, 173, 1551 -1561.

AMA Style

S. C. Castle, J. C. Neff. What controls plant nutrient use in high elevation ecosystems? Oecologia. 2013; 173 (4):1551-1561.

Chicago/Turabian Style

S. C. Castle; J. C. Neff. 2013. "What controls plant nutrient use in high elevation ecosystems?" Oecologia 173, no. 4: 1551-1561.

Journal article
Published: 01 April 2013 in Geochimica et Cosmochimica Acta
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Corey Lawrence; Richard L. Reynolds; Michael E. Ketterer; Jason Neff. Aeolian controls of soil geochemistry and weathering fluxes in high-elevation ecosystems of the Rocky Mountains, Colorado. Geochimica et Cosmochimica Acta 2013, 107, 27 -46.

AMA Style

Corey Lawrence, Richard L. Reynolds, Michael E. Ketterer, Jason Neff. Aeolian controls of soil geochemistry and weathering fluxes in high-elevation ecosystems of the Rocky Mountains, Colorado. Geochimica et Cosmochimica Acta. 2013; 107 ():27-46.

Chicago/Turabian Style

Corey Lawrence; Richard L. Reynolds; Michael E. Ketterer; Jason Neff. 2013. "Aeolian controls of soil geochemistry and weathering fluxes in high-elevation ecosystems of the Rocky Mountains, Colorado." Geochimica et Cosmochimica Acta 107, no. : 27-46.