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• 21. [Article] Carbon Dynamics in Response to Land Cover Change in Tropical Peatlands, Kalimantan, Indonesia

  This study focuses in providing the knowledge on carbon (C) stocks, emission and ecosystem productivity related to land use/land cover change in tropical peatlands. The field research activities were ...

  Citation × Citation Citation Abstract Copy Title: Carbon Dynamics in Response to Land Cover Change in Tropical Peatlands, Kalimantan, Indonesia Author: Basuki, Imam This study focuses in providing the knowledge on carbon (C) stocks, emission and ecosystem productivity related to land use/land cover change in tropical peatlands. The field research activities were conducted for about 17 months between August 2013 to December 2015, at Pematang Gadung peat dome (peat depth up to 10.5 m), Ketapang Regency, West Kalimantan, Indonesia. The objectives of this study were: a). to quantify C stocks of tropical coastal peat swamp forest, and the potential impact of forest degradation due to draining and logging activities on the forest’s carbon stocks; b). to examine the change in ecosystem C stocks and the potential C emissions in relation to land conversion from intact peat swamp forest (PSF) to logged peat forest (LPSF), early seral (ES) and oil palm plantation (OP); and c). to estimate net primary production (NPP) and net ecosystem production (NEP) in peat swamp forests, logged peat forest, early seral and smallholder - oil palm plantations. The intact peat forest sites have higher total aboveground C stocks (125 Mg C ha-1) than the logged peat forest sites (77 Mg C ha-1). Mean depths of the LPSF was 725 cm and the PSF was 915 cm (p= 0.06). Mean peat carbon stocks at PSF was 4,243 Mg C ha-1, higher than at LPSF that was 3,675 Mg C ha-1. Logging and draining had reduced the biomass of trees and the peat carbon pools. My study demonstrated that tropical coastal PSF has the largest total carbon stocks among terrestrial ecosystems on earth. The large carbon stocks and high rates of PSF degradation, points to the relevance for inclusion of PSF in nationally appropriate climate change mitigation and adaptation strategies. The mean ecosystem carbon stock for the PSF sites was 4,401 Mg C ha-1. Ecosystem C stocks of LPSF, ES and OP was 3,768, 3,147, and 3,442 Mg C ha-1, respectively. PSF stocks was significantly higher than the degraded land covers. At all sites, soils comprised > 96% of the mean ecosystem carbon stock. Using the estimation based on ecosystem carbon loss to total peat depths, the conversion of PSF to LPSF, ES and OP was estimated to result in a net loss of 1,982, 4,259 and 3,176 Mg C-CO2 ha-1, respectively. My results confirm that land cover change significantly impacted soil properties and reduced ecosystem carbon stocks. The tropical peatlands need urgent and significant efforts in conservation and restoration, to regain its function as a C sink and mitigate climate change. I found that land use/land cover change resulted in large shifts in NPP and NEP. LPSF, ES and OP have significantly lower NPP (11.1 Mg C ha-1 yr-1, 10.8 Mg C ha-1 yr-1 and 3.7 Mg C ha-1 yr-1, respectively) than PSF (13.2 Mg C ha-1 yr-1). ES showed lower heterotrophic respiration (30.7 Mg CO2 ha-1 yr-1) than PSF, LPSF and OP (37.7 Mg CO2 ha-1 yr-1, 40.7 Mg CO2 ha-1 yr-1, 38.7 Mg CO2 ha-1 yr-1, respectively). LPSF and OP were net carbon sources; they have negative mean NEP values (-0.1 Mg CO2-e ha-1 yr-1 and -25.1 Mg CO2-e ha-1 yr-1, respectively). In contrast PSF and ES were net carbon sinks (10.8 Mg CO2-e ha-1 yr-1 and 9.1 CCO2 ha-1 yr-1, respectively). PSF is among the most productive of terrestrial ecosystems, with an NPP exceeding that of many tropical rain forests and similar to the most productive mangrove ecosystems. I found that land use decreases productivity of the LPSF and OP sites. The ES had a similar NEP to the PSF, but frequent fires in this ecosystem likely offset carbon gains during the fire intervals. Land use change and forest degradation have shifted tropical PSFs from net carbon sinks to net carbon sources. My study demonstrated that land conversion in tropical peat swamp forests should be halted and degraded peatlands need to be restored in order to mitigate climate change. Title: Carbon Dynamics in Response to Land Cover Change in Tropical Peatlands, Kalimantan, Indonesia Author: Basuki, Imam This study focuses in providing the knowledge on carbon (C) stocks, emission and ecosystem productivity related to land use/land cover change in tropical peatlands. The field research activities were conducted for about 17 months between August 2013 to December 2015, at Pematang Gadung peat dome (peat depth up to 10.5 m), Ketapang Regency, West Kalimantan, Indonesia. The objectives of this study were: a). to quantify C stocks of tropical coastal peat swamp forest, and the potential impact of forest degradation due to draining and logging activities on the forest’s carbon stocks; b). to examine the change in ecosystem C stocks and the potential C emissions in relation to land conversion from intact peat swamp forest (PSF) to logged peat forest (LPSF), early seral (ES) and oil palm plantation (OP); and c). to estimate net primary production (NPP) and net ecosystem production (NEP) in peat swamp forests, logged peat forest, early seral and smallholder - oil palm plantations. The intact peat forest sites have higher total aboveground C stocks (125 Mg C ha-1) than the logged peat forest sites (77 Mg C ha-1). Mean depths of the LPSF was 725 cm and the PSF was 915 cm (p= 0.06). Mean peat carbon stocks at PSF was 4,243 Mg C ha-1, higher than at LPSF that was 3,675 Mg C ha-1. Logging and draining had reduced the biomass of trees and the peat carbon pools. My study demonstrated that tropical coastal PSF has the largest total carbon stocks among terrestrial ecosystems on earth. The large carbon stocks and high rates of PSF degradation, points to the relevance for inclusion of PSF in nationally appropriate climate change mitigation and adaptation strategies. The mean ecosystem carbon stock for the PSF sites was 4,401 Mg C ha-1. Ecosystem C stocks of LPSF, ES and OP was 3,768, 3,147, and 3,442 Mg C ha-1, respectively. PSF stocks was significantly higher than the degraded land covers. At all sites, soils comprised > 96% of the mean ecosystem carbon stock. Using the estimation based on ecosystem carbon loss to total peat depths, the conversion of PSF to LPSF, ES and OP was estimated to result in a net loss of 1,982, 4,259 and 3,176 Mg C-CO2 ha-1, respectively. My results confirm that land cover change significantly impacted soil properties and reduced ecosystem carbon stocks. The tropical peatlands need urgent and significant efforts in conservation and restoration, to regain its function as a C sink and mitigate climate change. I found that land use/land cover change resulted in large shifts in NPP and NEP. LPSF, ES and OP have significantly lower NPP (11.1 Mg C ha-1 yr-1, 10.8 Mg C ha-1 yr-1 and 3.7 Mg C ha-1 yr-1, respectively) than PSF (13.2 Mg C ha-1 yr-1). ES showed lower heterotrophic respiration (30.7 Mg CO2 ha-1 yr-1) than PSF, LPSF and OP (37.7 Mg CO2 ha-1 yr-1, 40.7 Mg CO2 ha-1 yr-1, 38.7 Mg CO2 ha-1 yr-1, respectively). LPSF and OP were net carbon sources; they have negative mean NEP values (-0.1 Mg CO2-e ha-1 yr-1 and -25.1 Mg CO2-e ha-1 yr-1, respectively). In contrast PSF and ES were net carbon sinks (10.8 Mg CO2-e ha-1 yr-1 and 9.1 CCO2 ha-1 yr-1, respectively). PSF is among the most productive of terrestrial ecosystems, with an NPP exceeding that of many tropical rain forests and similar to the most productive mangrove ecosystems. I found that land use decreases productivity of the LPSF and OP sites. The ES had a similar NEP to the PSF, but frequent fires in this ecosystem likely offset carbon gains during the fire intervals. Land use change and forest degradation have shifted tropical PSFs from net carbon sinks to net carbon sources. My study demonstrated that land conversion in tropical peat swamp forests should be halted and degraded peatlands need to be restored in order to mitigate climate change. Close

• 22. [Article] Examination of Human Impacts on the Biodiversity and Ecology of Lichen and Moss Communities

  Globally, more than half of the world's population is living in urban areas and it is well accepted that human activities (e.g. climate warming, pollution, landscape homogenization) pose a multitude of ...

  Citation × Citation Citation Abstract Copy Title: Examination of Human Impacts on the Biodiversity and Ecology of Lichen and Moss Communities Author: Prather, Hannah Marie Year: 2017 Globally, more than half of the world's population is living in urban areas and it is well accepted that human activities (e.g. climate warming, pollution, landscape homogenization) pose a multitude of threats to ecosystems. Largely, human-related impacts on biodiversity will hold consequences for larger ecological processes and research looking into human impacts on sensitive epiphytic lichen and moss communities is an emerging area of research. While seemingly small, lichen and moss communities exist on nearly every terrestrial ecosystem on Earth and contribute to whole-system processes (e.g. hydrology, mineral cycling, food web energetics) worldwide. To further examine human impacts on epiphytic communities, I conducted three studies examining urbanization and climate warming effects on epiphytic lichen and moss biodiversity and ecology. In the first study I revisited a historic urban lichen community study to assess how urban lichen communities have responded to regional air quality changes occurring over the last nearly two decades. I further investigated, for the first time, the biodiversity of urban tree canopy-dwelling lichen communities in a native coniferous tree species, Pseudotsuga menziesii. I found that urban parks and forested areas harbor a species rich community of lichens epiphytes. Further, I found evidence for the distinct homogenization of urban epiphytic lichen communities, suggesting that expanding beyond simplistic measures of biodiversity to consider community composition and functional biodiversity may be necessary when assessing the ecology and potential ecosystem services of epiphyte communites within urbanizing landscapes. Next, I present the first tall tree canopy study across a regional gradient of urbanization near Portland, Oregon, USA. I found that tall tree canopy epiphyte communities change dramatically along gradients of increasing urbanization, most notably by the transitioning of species functional groups from sensitive, oligotrophic species to a dominance of urban-tolerant, eutrophic species. The implications these dramatic shifts in species composition have on essential PNW ecosystem processes, like N-fixation and canopy microclimate regulation, is still not well understood and is difficult to formally evaluate. However, I find strong evidence that native conifer trees in urban areas may provide a diversity of essential ecosystem services, including providing stratified habitat for epiphyte communities and their associated micro arthropod communities and the scavenging of atmospherically deposited nutrients. Future work is needed to understand how losses in canopy N fixation and species with large biomass (both lichens and bryophytes) will affect nutrient and hydrologic cycling in the PNW region, which continue to undergo rapid growth and urbanization. The final chapter investigates the impacts of passive warming by Open Top Chambers (OTCs) in moss-dominated ecosystems located on the Western Antarctic Peninsula, an area of increasing climate warming. I compared species-specific temperature effects, moss canopy morphology, sexual reproductive effort and invertebrate communities between OTC and control moss communities for two moss species, Polytrichastrum alpinum and Sanionia uncinata, that make up over 65% of the terrestrial vegetative cover in the area. I found distinct reproductive shifts in P. alpinum under passive warming compared to controls. Moss communities under warming also had substantially larger total invertebrate communities than those in control moss communities, and invertebrate communities were significantly affected by moss species and moss reproductive effort. Further, substantial species-specific thermal differences among contiguous patches of these dominant moss species were revealed. These results suggest that continued warming will differentially impact the reproductive output of Antarctic moss species and is likely to dramatically alter terrestrial ecosystems dynamics from the bottom up. This combined work provides a diverse contribution to the field of epiphyte ecology and biology by providing new insights on how human impacts will affect epiphyte lichen and moss communities across diverse ecosystems, in light of a rapidly changing planet. Title: Examination of Human Impacts on the Biodiversity and Ecology of Lichen and Moss Communities Author: Prather, Hannah Marie Year: 2017 Globally, more than half of the world's population is living in urban areas and it is well accepted that human activities (e.g. climate warming, pollution, landscape homogenization) pose a multitude of threats to ecosystems. Largely, human-related impacts on biodiversity will hold consequences for larger ecological processes and research looking into human impacts on sensitive epiphytic lichen and moss communities is an emerging area of research. While seemingly small, lichen and moss communities exist on nearly every terrestrial ecosystem on Earth and contribute to whole-system processes (e.g. hydrology, mineral cycling, food web energetics) worldwide. To further examine human impacts on epiphytic communities, I conducted three studies examining urbanization and climate warming effects on epiphytic lichen and moss biodiversity and ecology. In the first study I revisited a historic urban lichen community study to assess how urban lichen communities have responded to regional air quality changes occurring over the last nearly two decades. I further investigated, for the first time, the biodiversity of urban tree canopy-dwelling lichen communities in a native coniferous tree species, Pseudotsuga menziesii. I found that urban parks and forested areas harbor a species rich community of lichens epiphytes. Further, I found evidence for the distinct homogenization of urban epiphytic lichen communities, suggesting that expanding beyond simplistic measures of biodiversity to consider community composition and functional biodiversity may be necessary when assessing the ecology and potential ecosystem services of epiphyte communites within urbanizing landscapes. Next, I present the first tall tree canopy study across a regional gradient of urbanization near Portland, Oregon, USA. I found that tall tree canopy epiphyte communities change dramatically along gradients of increasing urbanization, most notably by the transitioning of species functional groups from sensitive, oligotrophic species to a dominance of urban-tolerant, eutrophic species. The implications these dramatic shifts in species composition have on essential PNW ecosystem processes, like N-fixation and canopy microclimate regulation, is still not well understood and is difficult to formally evaluate. However, I find strong evidence that native conifer trees in urban areas may provide a diversity of essential ecosystem services, including providing stratified habitat for epiphyte communities and their associated micro arthropod communities and the scavenging of atmospherically deposited nutrients. Future work is needed to understand how losses in canopy N fixation and species with large biomass (both lichens and bryophytes) will affect nutrient and hydrologic cycling in the PNW region, which continue to undergo rapid growth and urbanization. The final chapter investigates the impacts of passive warming by Open Top Chambers (OTCs) in moss-dominated ecosystems located on the Western Antarctic Peninsula, an area of increasing climate warming. I compared species-specific temperature effects, moss canopy morphology, sexual reproductive effort and invertebrate communities between OTC and control moss communities for two moss species, Polytrichastrum alpinum and Sanionia uncinata, that make up over 65% of the terrestrial vegetative cover in the area. I found distinct reproductive shifts in P. alpinum under passive warming compared to controls. Moss communities under warming also had substantially larger total invertebrate communities than those in control moss communities, and invertebrate communities were significantly affected by moss species and moss reproductive effort. Further, substantial species-specific thermal differences among contiguous patches of these dominant moss species were revealed. These results suggest that continued warming will differentially impact the reproductive output of Antarctic moss species and is likely to dramatically alter terrestrial ecosystems dynamics from the bottom up. This combined work provides a diverse contribution to the field of epiphyte ecology and biology by providing new insights on how human impacts will affect epiphyte lichen and moss communities across diverse ecosystems, in light of a rapidly changing planet. Close

• 23. [Article] Large Predators Limit Herbivore Densities in Northern Forest Ecosystems

  This is the author's peer-reviewed accepted manuscript. The original publication is copyrighted and published by Springer and is available at www.springerlink.com. NEWS COVERAGE: A news release based ...

  Citation × Citation Citation Abstract Copy Title: Large Predators Limit Herbivore Densities in Northern Forest Ecosystems Author: Beschta, Robert L., Ripple, William J. This is the author's peer-reviewed accepted manuscript. The original publication is copyrighted and published by Springer and is available at www.springerlink.com. NEWS COVERAGE: A news release based on this journal publication, which is written for a lay audience and has been approved by an author of the study, is available online: http://bit.ly/HscXfe Title: Large Predators Limit Herbivore Densities in Northern Forest Ecosystems Author: Beschta, Robert L., Ripple, William J. This is the author's peer-reviewed accepted manuscript. The original publication is copyrighted and published by Springer and is available at www.springerlink.com. NEWS COVERAGE: A news release based on this journal publication, which is written for a lay audience and has been approved by an author of the study, is available online: http://bit.ly/HscXfe Close

• 24. [Article] Susceptibility of riparian soil invertebrates to the herbicide triclopyr

  Riparian zones of Pacific Northwest forests have high species diversity and abundance and act as an important interface between the aquatic and terrestrial ecosystems. In addition, riparian zones comprise ...

  Citation × Citation Citation Abstract Copy Title: Susceptibility of riparian soil invertebrates to the herbicide triclopyr Author: Moran, Patrick (Patrick William) Riparian zones of Pacific Northwest forests have high species diversity and abundance and act as an important interface between the aquatic and terrestrial ecosystems. In addition, riparian zones comprise a significant portion of the total buffer zone established during commercial forest production to protect aquatic ecosystems from adjacent management activities. Riparian soil invertebrates indigenous to Pacific Northwest forest ecosystems were chosen to investigate impacts from herbicide use. Species chosen for toxicity testing inhabit riparian zones of western Oregon Forests and were collected from the field. The species tested included; two ground beetles, Coleoptera; Carabidae, (Pterostichu inanis) Horn, and, (Scaphinotus marginalus) Fisher; an isopod (Ligidium sp); and a millipede (Harpaphe haydeniana haydeniana) Wood, Polydesmida; Xestodesmidaie. The formulated product of a herbicide widely used in western Oregon forests, Garlon 4, and a specialty formulation of Garlon 4, (XRM-4714 Blank) without the active ingredient triclopyr, were applied via a cabinet sprayer to a soil surface in accordance with a standard soil test method. At the recommended field rate of 4.48kg/ha, the isopod displayed significant mortality after 7-Day exposure, however the other four species were unaffected. The order of susceptibility based on 14-Day LC₅₀ estimates, (kg/ha), for these four species was, P. inanis (38.6)>S. marginalis (34.2)>H. haydeniana (5.1)>Ligidum sp (4.7). The isopod and millipede species exposed to the Garton 4 blank formulation for fourteen days resulted LC₅₀ estimates twice and nine-times higher than from the formulated product, respectively. The potential for this data in estimating the Hazardous Concentration to 5% of the species in the riparian forest community is also discussed. Title: Susceptibility of riparian soil invertebrates to the herbicide triclopyr Author: Moran, Patrick (Patrick William) Riparian zones of Pacific Northwest forests have high species diversity and abundance and act as an important interface between the aquatic and terrestrial ecosystems. In addition, riparian zones comprise a significant portion of the total buffer zone established during commercial forest production to protect aquatic ecosystems from adjacent management activities. Riparian soil invertebrates indigenous to Pacific Northwest forest ecosystems were chosen to investigate impacts from herbicide use. Species chosen for toxicity testing inhabit riparian zones of western Oregon Forests and were collected from the field. The species tested included; two ground beetles, Coleoptera; Carabidae, (Pterostichu inanis) Horn, and, (Scaphinotus marginalus) Fisher; an isopod (Ligidium sp); and a millipede (Harpaphe haydeniana haydeniana) Wood, Polydesmida; Xestodesmidaie. The formulated product of a herbicide widely used in western Oregon forests, Garlon 4, and a specialty formulation of Garlon 4, (XRM-4714 Blank) without the active ingredient triclopyr, were applied via a cabinet sprayer to a soil surface in accordance with a standard soil test method. At the recommended field rate of 4.48kg/ha, the isopod displayed significant mortality after 7-Day exposure, however the other four species were unaffected. The order of susceptibility based on 14-Day LC₅₀ estimates, (kg/ha), for these four species was, P. inanis (38.6)>S. marginalis (34.2)>H. haydeniana (5.1)>Ligidum sp (4.7). The isopod and millipede species exposed to the Garton 4 blank formulation for fourteen days resulted LC₅₀ estimates twice and nine-times higher than from the formulated product, respectively. The potential for this data in estimating the Hazardous Concentration to 5% of the species in the riparian forest community is also discussed. Close

• 25. [Article] N₂-Fixing Red Alder Indirectly Accelerates Ecosystem Nitrogen Cycling

  This is the publisher’s final pdf. The published article is copyrighted by Springer and can be found at: http://www.springerlink.com/content/101552/. To the best of our knowledge, one or more authors of ...

  Citation × Citation Citation Abstract Copy Title: N₂-Fixing Red Alder Indirectly Accelerates Ecosystem Nitrogen Cycling Author: Matkins, Joselin J., Hibbs, David E., Perakis, Steven S. This is the publisher’s final pdf. The published article is copyrighted by Springer and can be found at: http://www.springerlink.com/content/101552/. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. Title: N₂-Fixing Red Alder Indirectly Accelerates Ecosystem Nitrogen Cycling Author: Matkins, Joselin J., Hibbs, David E., Perakis, Steven S. This is the publisher’s final pdf. The published article is copyrighted by Springer and can be found at: http://www.springerlink.com/content/101552/. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. Close

• 26. [Article] Detecting Trends in Landuse and Landcover Change of Nech Sar National Park, Ethiopia

  To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Springer ...

  Citation × Citation Citation Abstract Copy Title: Detecting Trends in Landuse and Landcover Change of Nech Sar National Park, Ethiopia Author: Fetene, Aramde, Prasse, Ruediger, Yang, Zhiqiang, Yeshitela, Kumelachew, Hilker, Thomas, Cohen, Warren To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Springer Verlag and can be found at: http://link.springer.com/journal/267 Title: Detecting Trends in Landuse and Landcover Change of Nech Sar National Park, Ethiopia Author: Fetene, Aramde, Prasse, Ruediger, Yang, Zhiqiang, Yeshitela, Kumelachew, Hilker, Thomas, Cohen, Warren To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Springer Verlag and can be found at: http://link.springer.com/journal/267 Close

• 27. [Article] Honeggeriella complexa gen. et sp. nov., a heteromerous lichen from the lower cretaceous of Vancouver Island (British Columbia, Canada)

  This is the publisher’s final pdf. The published article is copyrighted by Botanical Society of America and can be found at: http://www.botany.org/.

  Citation × Citation Citation Abstract Copy Title: Honeggeriella complexa gen. et sp. nov., a heteromerous lichen from the lower cretaceous of Vancouver Island (British Columbia, Canada) Author: Tomescu, Alexandru M. F., Stockey, Ruth A., Matsunaga, Kelly K. S. This is the publisher’s final pdf. The published article is copyrighted by Botanical Society of America and can be found at: http://www.botany.org/. Title: Honeggeriella complexa gen. et sp. nov., a heteromerous lichen from the lower cretaceous of Vancouver Island (British Columbia, Canada) Author: Tomescu, Alexandru M. F., Stockey, Ruth A., Matsunaga, Kelly K. S. This is the publisher’s final pdf. The published article is copyrighted by Botanical Society of America and can be found at: http://www.botany.org/. Close

• 28. [Article] Winter Climate Change Affects Growing-Season Soil Microbial Biomass and Activity in Northern Hardwood Forests

  Understanding the responses of terrestrial ecosystems to global change remains a major challenge of ecological research. We exploited a natural elevation gradient in a northern hardwood forest to determine ...

  Citation × Citation Citation Abstract Copy Title: Winter Climate Change Affects Growing-Season Soil Microbial Biomass and Activity in Northern Hardwood Forests Author: Durán, Jorge, Morse, Jennifer L., Groffman, Peter M., Campbell, John L., Christenson, Lynn M., Driscoll, Charles T., Fahey, Timothy J., Fisk, Melany C., Mitchell, Mryon J., Templer, Pamela H. Year: 2014 Understanding the responses of terrestrial ecosystems to global change remains a major challenge of ecological research. We exploited a natural elevation gradient in a northern hardwood forest to determine how reductions in snow accumulation, expected with climate change, directly affect dynamics of soil winter frost, and indirectly soil microbial biomass and activity during the growing season. Soils from lower elevation plots, which accumulated less snow and experienced more soil temperature variability during the winter (and likely more freeze/thaw events), had less extractable inorganic nitrogen (N), lower rates of microbial N production via potential net N mineralization and nitrification, and higher potential microbial respiration during the growing season. Potential nitrate production rates during the growing season were particularly sensitive to changes in winter snow pack accumulation and winter soil temperature variability, especially in spring. Effects of elevation and winter conditions on N transformation rates dif­ fered from those on potential microbial respiration, suggesting that N-related processes might respond differently to winter climate change in northern hardwood forests than C-related processes. Title: Winter Climate Change Affects Growing-Season Soil Microbial Biomass and Activity in Northern Hardwood Forests Author: Durán, Jorge, Morse, Jennifer L., Groffman, Peter M., Campbell, John L., Christenson, Lynn M., Driscoll, Charles T., Fahey, Timothy J., Fisk, Melany C., Mitchell, Mryon J., Templer, Pamela H. Year: 2014 Understanding the responses of terrestrial ecosystems to global change remains a major challenge of ecological research. We exploited a natural elevation gradient in a northern hardwood forest to determine how reductions in snow accumulation, expected with climate change, directly affect dynamics of soil winter frost, and indirectly soil microbial biomass and activity during the growing season. Soils from lower elevation plots, which accumulated less snow and experienced more soil temperature variability during the winter (and likely more freeze/thaw events), had less extractable inorganic nitrogen (N), lower rates of microbial N production via potential net N mineralization and nitrification, and higher potential microbial respiration during the growing season. Potential nitrate production rates during the growing season were particularly sensitive to changes in winter snow pack accumulation and winter soil temperature variability, especially in spring. Effects of elevation and winter conditions on N transformation rates dif­ fered from those on potential microbial respiration, suggesting that N-related processes might respond differently to winter climate change in northern hardwood forests than C-related processes. Close

• 29. [Article] On the origin and timing of rapid changes in atmospheric methane during the Last Glacial Period

  This is the publisher’s final pdf. The published article is copyrighted by the American Geophysical Union and can be found at: http://www.agu.org/journals/gb/index.shtml.

  Citation × Citation Citation Abstract Copy Title: On the origin and timing of rapid changes in atmospheric methane during the Last Glacial Period Author: Steig, Eric J., Harder, Susan, Brook, Edward J., Severinghaus, Jeff, Sucher, Cara M. This is the publisher’s final pdf. The published article is copyrighted by the American Geophysical Union and can be found at: http://www.agu.org/journals/gb/index.shtml. Title: On the origin and timing of rapid changes in atmospheric methane during the Last Glacial Period Author: Steig, Eric J., Harder, Susan, Brook, Edward J., Severinghaus, Jeff, Sucher, Cara M. This is the publisher’s final pdf. The published article is copyrighted by the American Geophysical Union and can be found at: http://www.agu.org/journals/gb/index.shtml. Close

• 30. [Article] Empirical assessment of uncertainties of meteorological parameters and turbulent fluxes in the AmeriFlux network

  This is the publisher’s final pdf. The published article is copyrighted by the American Geophysical Union and can be found at: http://onlinelibrary.wiley.com/journal/10.1002/%28ISSN%292169-8961.

  Citation × Citation Citation Abstract Copy Title: Empirical assessment of uncertainties of meteorological parameters and turbulent fluxes in the AmeriFlux network Author: Law, Beverly E., Schmidt, Andres, Chan, W. Stephen, Hanson, Chad This is the publisher’s final pdf. The published article is copyrighted by the American Geophysical Union and can be found at: http://onlinelibrary.wiley.com/journal/10.1002/%28ISSN%292169-8961. Title: Empirical assessment of uncertainties of meteorological parameters and turbulent fluxes in the AmeriFlux network Author: Law, Beverly E., Schmidt, Andres, Chan, W. Stephen, Hanson, Chad This is the publisher’s final pdf. The published article is copyrighted by the American Geophysical Union and can be found at: http://onlinelibrary.wiley.com/journal/10.1002/%28ISSN%292169-8961. Close