Search

Search Results

• 41. [Article] Dynamics of water-soluble carbon in forest soils of contrasting fertility

  Most soil organic C is in a stable form, associated with clay minerals in the upper soil profile. Upon environmental and land-use changes, stable soil C is subject to losses, which influence the global ...

  Citation × Citation Citation Abstract Copy Title: Dynamics of water-soluble carbon in forest soils of contrasting fertility Author: Wagai, Rota Most soil organic C is in a stable form, associated with clay minerals in the upper soil profile. Upon environmental and land-use changes, stable soil C is subject to losses, which influence the global C cycle and the productivity of terrestrial ecosystems. However, mechanisms controlling soil C destabilization are not well understood. Microbial respiration and leaching are the two major fates of destabilized C. I hypothesized that water-soluble C plays an important role in soil C turnover and studied the susceptibility of water-soluble C both to leaching and to microbial degradation. Furthermore, I studied factors influencing the amount of water-soluble C and its biodegradability using five soils from a wide fertility gradient. First, soil columns (20 cm of top soil) with and without Douglas-fir seedlings were leached every 2 weeks for 20 weeks and the soils were extracted with water before and after the 20-week study period. Extracts contained 8 to 17 times more dissolved organic C (DOC) than did leachates. Similarly, biodegradable DOC (BDOC) in extracts was 4 to 96 times that in leachates. The leachable C pool was constant over the 20 weeks regardless of the presence of tree seedlings in soil leaching columns, while the extractable C pooi declined by 31 to 40% over time. A soil C destabilization model was proposed based on the changes in measured C pools (particulate, water-extractable, and leachable C) and the estimates of soil respiration and microbial biomass from a previous work. Microbial respiration accounted for 86 to 92% of the C destabilized. Leached C accounted for the remaining 8 to 14%, indicating its minor role in C mobilization in the system studied. However, the model didn't rule out the possibility that extractable C accounts for a significant portion of microbial respiration. Second, the hypothesis that water-extractable C is a major energy source for microbes was tested using Douglas-fir forest soils from two sites (Cascade Head and Wind River) and with and without red-alder influence. Despite a large range of soil fertility (C:N ratio of 13 to 31), C extracted before and after the 2-month soil incubation showed a strong correlation with the C respired during the incubation period (r2 = 0.71 and 0.92), suggesting the efficacy of extractable C pools to predict the availability of C to soil microbes. Furthermore, DOC and BDOC pool were relatively constant during the 2- month incubation, indicating the possibility that a rapid regeneration and degradation of extractable C explain the measured microbial respiration during the study period. No clear correlation was found between DOC and dissolved organic N. Across all stands, soil C:N ratio showed a strong correlation with the relative amount of BDOC in the DOC incubation (r2 = 0.72) and with the relative amount of C respired from bulk soil (per g C basis) at the end of incubation period (r2 = 0.72), suggesting a strong influence of soil C:N on the overall C availability to soil microbes both in solution and solid phase. Water-extractable C deserves continued attention as a strong predictor of available C for soil microbes and as a potentially significant energy source for microbial respiration. More information is needed to estimate the regeneration rate of labile extractable C and to identify factors controlling soil C degradation. Title: Dynamics of water-soluble carbon in forest soils of contrasting fertility Author: Wagai, Rota Most soil organic C is in a stable form, associated with clay minerals in the upper soil profile. Upon environmental and land-use changes, stable soil C is subject to losses, which influence the global C cycle and the productivity of terrestrial ecosystems. However, mechanisms controlling soil C destabilization are not well understood. Microbial respiration and leaching are the two major fates of destabilized C. I hypothesized that water-soluble C plays an important role in soil C turnover and studied the susceptibility of water-soluble C both to leaching and to microbial degradation. Furthermore, I studied factors influencing the amount of water-soluble C and its biodegradability using five soils from a wide fertility gradient. First, soil columns (20 cm of top soil) with and without Douglas-fir seedlings were leached every 2 weeks for 20 weeks and the soils were extracted with water before and after the 20-week study period. Extracts contained 8 to 17 times more dissolved organic C (DOC) than did leachates. Similarly, biodegradable DOC (BDOC) in extracts was 4 to 96 times that in leachates. The leachable C pool was constant over the 20 weeks regardless of the presence of tree seedlings in soil leaching columns, while the extractable C pooi declined by 31 to 40% over time. A soil C destabilization model was proposed based on the changes in measured C pools (particulate, water-extractable, and leachable C) and the estimates of soil respiration and microbial biomass from a previous work. Microbial respiration accounted for 86 to 92% of the C destabilized. Leached C accounted for the remaining 8 to 14%, indicating its minor role in C mobilization in the system studied. However, the model didn't rule out the possibility that extractable C accounts for a significant portion of microbial respiration. Second, the hypothesis that water-extractable C is a major energy source for microbes was tested using Douglas-fir forest soils from two sites (Cascade Head and Wind River) and with and without red-alder influence. Despite a large range of soil fertility (C:N ratio of 13 to 31), C extracted before and after the 2-month soil incubation showed a strong correlation with the C respired during the incubation period (r2 = 0.71 and 0.92), suggesting the efficacy of extractable C pools to predict the availability of C to soil microbes. Furthermore, DOC and BDOC pool were relatively constant during the 2- month incubation, indicating the possibility that a rapid regeneration and degradation of extractable C explain the measured microbial respiration during the study period. No clear correlation was found between DOC and dissolved organic N. Across all stands, soil C:N ratio showed a strong correlation with the relative amount of BDOC in the DOC incubation (r2 = 0.72) and with the relative amount of C respired from bulk soil (per g C basis) at the end of incubation period (r2 = 0.72), suggesting a strong influence of soil C:N on the overall C availability to soil microbes both in solution and solid phase. Water-extractable C deserves continued attention as a strong predictor of available C for soil microbes and as a potentially significant energy source for microbial respiration. More information is needed to estimate the regeneration rate of labile extractable C and to identify factors controlling soil C degradation. Close

• 42. [Article] Performance of Linear and Nonlinear Two-Leaf Light Use Efficiency Models at Different Temporal Scales

  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 MDPI and ...

  Citation × Citation Citation Abstract Copy Title: Performance of Linear and Nonlinear Two-Leaf Light Use Efficiency Models at Different Temporal Scales Author: Law, Beverly E., Wu, Xiaocui, Ju, Weimin, et al., Zhou, Yanlian 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 MDPI and can be found at: http://www.mdpi.com/journal/remotesensing Title: Performance of Linear and Nonlinear Two-Leaf Light Use Efficiency Models at Different Temporal Scales Author: Law, Beverly E., Wu, Xiaocui, Ju, Weimin, et al., Zhou, Yanlian 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 MDPI and can be found at: http://www.mdpi.com/journal/remotesensing Close

• 43. [Article] Soil respiration response to experimental disturbances over 3 years

  Soil respiration is a major pathway for carbon cycling in terrestrial ecosystems yet little is known about its response to natural and anthropogenic disturbances. This study examined soil respiration response ...

  Citation × Citation Citation Abstract Copy Title: Soil respiration response to experimental disturbances over 3 years Soil respiration is a major pathway for carbon cycling in terrestrial ecosystems yet little is known about its response to natural and anthropogenic disturbances. This study examined soil respiration response to prescribed burning and thinning treatments in an old-growth, mixedconifer forest on the western slope of the Sierra Nevada Mountains. Experimental treatments were applied in 2001 using a full factorial design consisting of two levels of burning and three levels of thinning, and included: unburned–unthinned (UN), unburned–overstory thinned (US), unburned–understory thinned (UC), burned–unthinned (BN), burned–understory thinned (BC), and burned–overstory thinned (BS).We measured soil respiration rate (SRR), soil moisture (MS), soil temperature (TS), and litter depth (LD) for three replicates of each of three dominant patch types (closed canopy, open canopy, and ceanothus shrub) within each of the six treatments (n = 54). The same sampling points were measured from May to August in 2000 (pre-treatment) and in 2002, 2003, and 2004 (post-treatment). Within our sampling period there was as much as 37% variation ( p = 0.0005) between years in the undisturbed patches, which appeared to be driven by changes in precipitation. SRR also varied by year in all treated plots (US: p = 0.0516; UC: p = 0.0006; BN: p = 0.0158; and BC: p = 0.0040), with the exception of BS ( p = 0.3344). SRR response to disturbance varied with patch type, year, and treatment type. In most cases, burning and the combination of burning and thinning had less of an effect on mean SRR than thinning alone. Ceanothus patches appear to have recovered fastest, while treatment effects remained 3 years after thinning in closed canopy ( p = 0.0483 and 0.0333 in UC and US, respectively) and open canopy patches ( p = 0.0191 in US). Open canopy patches showed no response to any treatment aside from US. Both UC and US increased SRR in closed canopy and ceanothus patches, and US decreased SRR in open canopy patches. BS increased SRR in 2004 in closed canopy patches ( p = 0.0108), but no significant changes occurred in any patch type in response to BN or BC treatments. Across all treatments, the relationship of SRR with temperature, moisture, and litter depth changed in post-disturbance years. The results of this study can be used to help understand how management of Sierran mixed-conifer forests affects soil carbon sequestration. Title: Soil respiration response to experimental disturbances over 3 years Soil respiration is a major pathway for carbon cycling in terrestrial ecosystems yet little is known about its response to natural and anthropogenic disturbances. This study examined soil respiration response to prescribed burning and thinning treatments in an old-growth, mixedconifer forest on the western slope of the Sierra Nevada Mountains. Experimental treatments were applied in 2001 using a full factorial design consisting of two levels of burning and three levels of thinning, and included: unburned–unthinned (UN), unburned–overstory thinned (US), unburned–understory thinned (UC), burned–unthinned (BN), burned–understory thinned (BC), and burned–overstory thinned (BS).We measured soil respiration rate (SRR), soil moisture (MS), soil temperature (TS), and litter depth (LD) for three replicates of each of three dominant patch types (closed canopy, open canopy, and ceanothus shrub) within each of the six treatments (n = 54). The same sampling points were measured from May to August in 2000 (pre-treatment) and in 2002, 2003, and 2004 (post-treatment). Within our sampling period there was as much as 37% variation ( p = 0.0005) between years in the undisturbed patches, which appeared to be driven by changes in precipitation. SRR also varied by year in all treated plots (US: p = 0.0516; UC: p = 0.0006; BN: p = 0.0158; and BC: p = 0.0040), with the exception of BS ( p = 0.3344). SRR response to disturbance varied with patch type, year, and treatment type. In most cases, burning and the combination of burning and thinning had less of an effect on mean SRR than thinning alone. Ceanothus patches appear to have recovered fastest, while treatment effects remained 3 years after thinning in closed canopy ( p = 0.0483 and 0.0333 in UC and US, respectively) and open canopy patches ( p = 0.0191 in US). Open canopy patches showed no response to any treatment aside from US. Both UC and US increased SRR in closed canopy and ceanothus patches, and US decreased SRR in open canopy patches. BS increased SRR in 2004 in closed canopy patches ( p = 0.0108), but no significant changes occurred in any patch type in response to BN or BC treatments. Across all treatments, the relationship of SRR with temperature, moisture, and litter depth changed in post-disturbance years. The results of this study can be used to help understand how management of Sierran mixed-conifer forests affects soil carbon sequestration. Close

• 44. [Article] Soil respiration response to experimental disturbances over 3 years

  Soil respiration is a major pathway for carbon cycling in terrestrial ecosystems yet little is known about its response to natural and anthropogenic disturbances. This study examined soil respiration response ...

  Citation × Citation Citation Abstract Copy Title: Soil respiration response to experimental disturbances over 3 years Author: Ma, Siyan, Concilio, Amy, Ryu, Soung-Ryoul, Chen, Jiquan, North, Malcolm Soil respiration is a major pathway for carbon cycling in terrestrial ecosystems yet little is known about its response to natural and anthropogenic disturbances. This study examined soil respiration response to prescribed burning and thinning treatments in an old-growth, mixedconifer forest on the western slope of the Sierra Nevada Mountains. Experimental treatments were applied in 2001 using a full factorial design consisting of two levels of burning and three levels of thinning, and included: unburned–unthinned (UN), unburned–overstory thinned (US), unburned–understory thinned (UC), burned–unthinned (BN), burned–understory thinned (BC), and burned–overstory thinned (BS).We measured soil respiration rate (SRR), soil moisture (MS), soil temperature (TS), and litter depth (LD) for three replicates of each of three dominant patch types (closed canopy, open canopy, and ceanothus shrub) within each of the six treatments (n = 54). The same sampling points were measured from May to August in 2000 (pre-treatment) and in 2002, 2003, and 2004 (post-treatment). Within our sampling period there was as much as 37% variation ( p = 0.0005) between years in the undisturbed patches, which appeared to be driven by changes in precipitation. SRR also varied by year in all treated plots (US: p = 0.0516; UC: p = 0.0006; BN: p = 0.0158; and BC: p = 0.0040), with the exception of BS ( p = 0.3344). SRR response to disturbance varied with patch type, year, and treatment type. In most cases, burning and the combination of burning and thinning had less of an effect on mean SRR than thinning alone. Ceanothus patches appear to have recovered fastest, while treatment effects remained 3 years after thinning in closed canopy ( p = 0.0483 and 0.0333 in UC and US, respectively) and open canopy patches ( p = 0.0191 in US). Open canopy patches showed no response to any treatment aside from US. Both UC and US increased SRR in closed canopy and ceanothus patches, and US decreased SRR in open canopy patches. BS increased SRR in 2004 in closed canopy patches ( p = 0.0108), but no significant changes occurred in any patch type in response to BN or BC treatments. Across all treatments, the relationship of SRR with temperature, moisture, and litter depth changed in post-disturbance years. The results of this study can be used to help understand how management of Sierran mixed-conifer forests affects soil carbon sequestration. Title: Soil respiration response to experimental disturbances over 3 years Author: Ma, Siyan, Concilio, Amy, Ryu, Soung-Ryoul, Chen, Jiquan, North, Malcolm Soil respiration is a major pathway for carbon cycling in terrestrial ecosystems yet little is known about its response to natural and anthropogenic disturbances. This study examined soil respiration response to prescribed burning and thinning treatments in an old-growth, mixedconifer forest on the western slope of the Sierra Nevada Mountains. Experimental treatments were applied in 2001 using a full factorial design consisting of two levels of burning and three levels of thinning, and included: unburned–unthinned (UN), unburned–overstory thinned (US), unburned–understory thinned (UC), burned–unthinned (BN), burned–understory thinned (BC), and burned–overstory thinned (BS).We measured soil respiration rate (SRR), soil moisture (MS), soil temperature (TS), and litter depth (LD) for three replicates of each of three dominant patch types (closed canopy, open canopy, and ceanothus shrub) within each of the six treatments (n = 54). The same sampling points were measured from May to August in 2000 (pre-treatment) and in 2002, 2003, and 2004 (post-treatment). Within our sampling period there was as much as 37% variation ( p = 0.0005) between years in the undisturbed patches, which appeared to be driven by changes in precipitation. SRR also varied by year in all treated plots (US: p = 0.0516; UC: p = 0.0006; BN: p = 0.0158; and BC: p = 0.0040), with the exception of BS ( p = 0.3344). SRR response to disturbance varied with patch type, year, and treatment type. In most cases, burning and the combination of burning and thinning had less of an effect on mean SRR than thinning alone. Ceanothus patches appear to have recovered fastest, while treatment effects remained 3 years after thinning in closed canopy ( p = 0.0483 and 0.0333 in UC and US, respectively) and open canopy patches ( p = 0.0191 in US). Open canopy patches showed no response to any treatment aside from US. Both UC and US increased SRR in closed canopy and ceanothus patches, and US decreased SRR in open canopy patches. BS increased SRR in 2004 in closed canopy patches ( p = 0.0108), but no significant changes occurred in any patch type in response to BN or BC treatments. Across all treatments, the relationship of SRR with temperature, moisture, and litter depth changed in post-disturbance years. The results of this study can be used to help understand how management of Sierran mixed-conifer forests affects soil carbon sequestration. Close

• 45. [Article] Soil respiration response to experimental disturbances over 3 years

  Soil respiration is a major pathway for carbon cycling in terrestrial ecosystems yet little is known about its response to natural and anthropogenic disturbances. This study examined soil respiration response ...

  Citation × Citation Citation Abstract Copy Title: Soil respiration response to experimental disturbances over 3 years Author: North, Malcolm, Concilio, Amy, Ryu, Soung-Ryoul, Chen, Jiquan, Ma, Siyan Soil respiration is a major pathway for carbon cycling in terrestrial ecosystems yet little is known about its response to natural and anthropogenic disturbances. This study examined soil respiration response to prescribed burning and thinning treatments in an old-growth, mixed-conifer forest on the western slope of the Sierra Nevada Mountains. Experimental treatments were applied in 2001 using a full factorial design consisting of two levels of burning and three levels of thinning, and included: unburned–unthinned (UN), unburned–overstory thinned (US), unburned–understory thinned (UC), burned–unthinned (BN), burned–understory thinned (BC), and burned–overstory thinned (BS).We measured soil respiration rate (SRR), soil moisture (MS), soil temperature (TS), and litter depth (LD) for three replicates of each of three dominant patch types (closed canopy, open canopy, and ceanothus shrub) within each of the six treatments (n = 54). The same sampling points were measured from May to August in 2000 (pre-treatment) and in 2002, 2003, and 2004 (post-treatment). Within our sampling period there was as much as 37% variation (p = 0.0005) between years in the undisturbed patches, which appeared to be driven by changes in precipitation. SRR also varied by year in all treated plots (US: p = 0.0516; UC: p = 0.0006; BN: p = 0.0158; and BC: p = 0.0040), with the exception of BS (p = 0.3344). SRR response to disturbance varied with patch type, year, and treatment type. In most cases, burning and the combination of burning and thinning had less of an effect on mean SRR than thinning alone. Ceanothus patches appear to have recovered fastest, while treatment effects remained 3 years after thinning in closed canopy (p = 0.0483 and 0.0333 in UC and US, respectively) and open canopy patches (p = 0.0191 in US). Open canopy patches showed no response to any treatment aside from US. Both UC and US increased SRR in closed canopy and ceanothus patches, and US decreased SRR in open canopy patches. BS increased SRR in 2004 in closed canopy patches (p = 0.0108), but no significant changes occurred in any patch type in response to BN or BC treatments. Across all treatments, the relationship of SRR with temperature, moisture, and litter depth changed in post-disturbance years. The results of this study can be used to help understand how management of Sierran mixed-conifer forests affects soil carbon sequestration. Title: Soil respiration response to experimental disturbances over 3 years Author: North, Malcolm, Concilio, Amy, Ryu, Soung-Ryoul, Chen, Jiquan, Ma, Siyan Soil respiration is a major pathway for carbon cycling in terrestrial ecosystems yet little is known about its response to natural and anthropogenic disturbances. This study examined soil respiration response to prescribed burning and thinning treatments in an old-growth, mixed-conifer forest on the western slope of the Sierra Nevada Mountains. Experimental treatments were applied in 2001 using a full factorial design consisting of two levels of burning and three levels of thinning, and included: unburned–unthinned (UN), unburned–overstory thinned (US), unburned–understory thinned (UC), burned–unthinned (BN), burned–understory thinned (BC), and burned–overstory thinned (BS).We measured soil respiration rate (SRR), soil moisture (MS), soil temperature (TS), and litter depth (LD) for three replicates of each of three dominant patch types (closed canopy, open canopy, and ceanothus shrub) within each of the six treatments (n = 54). The same sampling points were measured from May to August in 2000 (pre-treatment) and in 2002, 2003, and 2004 (post-treatment). Within our sampling period there was as much as 37% variation (p = 0.0005) between years in the undisturbed patches, which appeared to be driven by changes in precipitation. SRR also varied by year in all treated plots (US: p = 0.0516; UC: p = 0.0006; BN: p = 0.0158; and BC: p = 0.0040), with the exception of BS (p = 0.3344). SRR response to disturbance varied with patch type, year, and treatment type. In most cases, burning and the combination of burning and thinning had less of an effect on mean SRR than thinning alone. Ceanothus patches appear to have recovered fastest, while treatment effects remained 3 years after thinning in closed canopy (p = 0.0483 and 0.0333 in UC and US, respectively) and open canopy patches (p = 0.0191 in US). Open canopy patches showed no response to any treatment aside from US. Both UC and US increased SRR in closed canopy and ceanothus patches, and US decreased SRR in open canopy patches. BS increased SRR in 2004 in closed canopy patches (p = 0.0108), but no significant changes occurred in any patch type in response to BN or BC treatments. Across all treatments, the relationship of SRR with temperature, moisture, and litter depth changed in post-disturbance years. The results of this study can be used to help understand how management of Sierran mixed-conifer forests affects soil carbon sequestration. Close

• 46. [Article] Climate seasonality limits leaf carbon assimilation and wood productivity in tropical forests

  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 the author(s) ...

  Citation × Citation Citation Abstract Copy Title: Climate seasonality limits leaf carbon assimilation and wood productivity in tropical forests Author: Chidumayo, Emmanuel N., Okada, Naoki, Toledo, José Julio, Rutishauser, Ervan, Volland, Franziska, Baker, Timothy R., Botosso, Paulo Cesar, Kanieski, Maria Raquel, Maza Chamba, Hector, Maria, Vivian R. B., Oberbauer, Steven F., Boanerges Souza, Danilo, Bräuning, Achim, Finger, César Augusto Guimarães, Elifuraha, Elisha, Graça, Paulo Maurício Lima de Alencastro, Figueiredo Filho, Afonso, Homeier, Jürgen, Toledo, Marisol, Marques, Renato, Pélissier, Raphaël, Verbesselt, Jan, Griffiths, Anthony D., Hérault, Bruno, Carvalho, Fabrício Alvim, de Oliveira, Edilson Consuelo, Mendivelso, Hooz Angela, Mbwambo, Lawrence, Anderson, Liana O., da Silva Mauricio, Paulo Henrique, Fedele, Marcio, Toma, Takeshi, Spannl, Susanne, O'Brien, Joseph J., Rowland, Lucy, Costa, Flavia Regina Capellotto, Lieberman, Milton Eugene, Brown, Foster Irving, Galvão, Franklin, Dalitz, Helmut, Clark, Deborah A., de Castro, Vinicius Resende, Couralet, Camille, Bowman, David M. J. S., Tomazello Filho, Mario, Gebrekirstos, Aster, Lisi, Claudio Sergio, Swaine, Michael D., Silva, Williamar Rodrigues, Drew, David M., Brede, Benjamin, Bonal, Damien, Kho, Lip Khoon, Roig, Fidel Alejandro, Silveira, Marcos, Grogan, James, Ross, Michael, Rossatto, Davi Rodrigo, Worbes, Martin, Malhi, Yadvinder, Camargo, Plínio Barbosa, Kohler, Sintia Valerio, Chagas, Rubens Koloski, Chave, Jérome, Ferreira Fedele, Ligia, Lieberman, Diana, Becker, Gabriel Sebastian, Dünisch, Oliver, Beeckman, Hans, de Souza Arruda, Luciano, Durigan, Giselda, Prior, Lynda D., Castro, Wendeson, Franco, Augusto César, Zanon, Magda Lea Bolzan, Guan, Kaiyu, Selhorst, Diogo, Krepkowski, Julia, Camarero, Jesus Julio, Koenig, Jennifer, Rossi, Vivien, Volkmer de Castilho, Carolina, Melgaço, Karina Liana Lisboa, Marques, Marcia C. M., López Ayala, José Luis, Wagner, Fabien H., Maeda, Eduardo Eijji, Aragão, Luiz E. O. C., Vincent, Grégoire, de Freitas Milani, Jaçanan Eloisa, Valdez Hernández, Juan Ignacio, Devineau, Jean-Louis, Freitas Júnior, João Lima, Stahl, Clément, Longhi Santos, Tomaz, Vieira, Simone Aparecida, Cardoso, Fernanda C. G., Murphy, Brett P., Santana, Hellen, Gliniars, Robert, Lemos-Filho, José Pires, Toledo, Marcos Miranda, Schulze, Mark 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 the author(s) and published by Copernicus Publications on behalf of the European Geosciences Union. The article can be found at: http://www.biogeosciences.net/ Title: Climate seasonality limits leaf carbon assimilation and wood productivity in tropical forests Author: Chidumayo, Emmanuel N., Okada, Naoki, Toledo, José Julio, Rutishauser, Ervan, Volland, Franziska, Baker, Timothy R., Botosso, Paulo Cesar, Kanieski, Maria Raquel, Maza Chamba, Hector, Maria, Vivian R. B., Oberbauer, Steven F., Boanerges Souza, Danilo, Bräuning, Achim, Finger, César Augusto Guimarães, Elifuraha, Elisha, Graça, Paulo Maurício Lima de Alencastro, Figueiredo Filho, Afonso, Homeier, Jürgen, Toledo, Marisol, Marques, Renato, Pélissier, Raphaël, Verbesselt, Jan, Griffiths, Anthony D., Hérault, Bruno, Carvalho, Fabrício Alvim, de Oliveira, Edilson Consuelo, Mendivelso, Hooz Angela, Mbwambo, Lawrence, Anderson, Liana O., da Silva Mauricio, Paulo Henrique, Fedele, Marcio, Toma, Takeshi, Spannl, Susanne, O'Brien, Joseph J., Rowland, Lucy, Costa, Flavia Regina Capellotto, Lieberman, Milton Eugene, Brown, Foster Irving, Galvão, Franklin, Dalitz, Helmut, Clark, Deborah A., de Castro, Vinicius Resende, Couralet, Camille, Bowman, David M. J. S., Tomazello Filho, Mario, Gebrekirstos, Aster, Lisi, Claudio Sergio, Swaine, Michael D., Silva, Williamar Rodrigues, Drew, David M., Brede, Benjamin, Bonal, Damien, Kho, Lip Khoon, Roig, Fidel Alejandro, Silveira, Marcos, Grogan, James, Ross, Michael, Rossatto, Davi Rodrigo, Worbes, Martin, Malhi, Yadvinder, Camargo, Plínio Barbosa, Kohler, Sintia Valerio, Chagas, Rubens Koloski, Chave, Jérome, Ferreira Fedele, Ligia, Lieberman, Diana, Becker, Gabriel Sebastian, Dünisch, Oliver, Beeckman, Hans, de Souza Arruda, Luciano, Durigan, Giselda, Prior, Lynda D., Castro, Wendeson, Franco, Augusto César, Zanon, Magda Lea Bolzan, Guan, Kaiyu, Selhorst, Diogo, Krepkowski, Julia, Camarero, Jesus Julio, Koenig, Jennifer, Rossi, Vivien, Volkmer de Castilho, Carolina, Melgaço, Karina Liana Lisboa, Marques, Marcia C. M., López Ayala, José Luis, Wagner, Fabien H., Maeda, Eduardo Eijji, Aragão, Luiz E. O. C., Vincent, Grégoire, de Freitas Milani, Jaçanan Eloisa, Valdez Hernández, Juan Ignacio, Devineau, Jean-Louis, Freitas Júnior, João Lima, Stahl, Clément, Longhi Santos, Tomaz, Vieira, Simone Aparecida, Cardoso, Fernanda C. G., Murphy, Brett P., Santana, Hellen, Gliniars, Robert, Lemos-Filho, José Pires, Toledo, Marcos Miranda, Schulze, Mark 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 the author(s) and published by Copernicus Publications on behalf of the European Geosciences Union. The article can be found at: http://www.biogeosciences.net/ Close

• 47. [Article] Lichen communities and caribou habitat in Denali National Park and Preserve, Alaska, USA

  Lichens play many important roles in subarctic terrestrial ecosystems by fixing nitrogen, colonizing rock and gravel, stabilizing otherwise bare soil, adding significantly to vegetation biodiversity and ...

  Citation × Citation Citation Abstract Copy Title: Lichen communities and caribou habitat in Denali National Park and Preserve, Alaska, USA Author: Nelson, Peter, 1970- Lichens play many important roles in subarctic terrestrial ecosystems by fixing nitrogen, colonizing rock and gravel, stabilizing otherwise bare soil, adding significantly to vegetation biodiversity and serving as the primary food for caribou in the winter. In these chapters, I analyzed lichen community and ecological trait structure along environmental gradients, map lichens using some of their unique spectral properties to generate lichen maps and study caribou habitat selection patterns in relation to lichens and other habitat variables. Morphological and life history traits of lichens influence their ecological roles through physiological limitations imposed by their form and photobionts, the algal or cyanobacterial partner. In chapter 2, I analyzed the lichen traits in relationship to environmental gradients, other forms of vegetation and time since fire in Denali National Park and Preserve, Alaska. Lichens with different photobionts reached different maxima along environmental gradients, these corresponding to variable water availability or specific biotic factors thought to favor that photobiont. Green algal lichens were most abundant in the alpine whereas cyanolichens peaked where shrub cover increased. Tripartite lichens were most abundant in middle elevation, mossy areas. Lichen growthforms peaked along desiccation and water absorption gradients. Lichens with small vegetative propagules were most abundant in lowland forests. Recent fire favored simple, Cladonia-form lichens with soredia that grow on wood whereas erect branched fruticose lichens, the "reindeer lichens", had only partially recovered 20-100 years after fire. These results imply interacting forces of water regulation, dispersal and optimum conditions for photosynthesis drive lichen trait frequency and abundance. The fungal partner within the lichen symbiosis produces many unique compounds that are often brightly colored. Other studies have attempted to map lichens using their distinctive spectral properties but no study has yet to target specific lichen compounds in order to better model lichen cover. In chapter 3, I focused on one yellow lichen compound, usnic acid, as the target for modeling lichen cover using Landsat 7 ETM+ satellite data. Usnic lichen cover had non-linear relationships with the three best predictors; elevation, blue and near-infrared bandpasses. Using these three predictors, I generated an usnic lichen map for Denali, which I use in chapter 4 for analyzing caribou habitat selection. I also modeled and mapped other vegetation groups corresponding to caribou diet items used later. My results show that some lichens may be directly mapped from space by targeting this specific compound produced by the fungus. Caribou depend on lichens for up to 66% of their winter diet but other factors, such as snow, affect their access to the lichens. In chapter 4, I analyzed caribou habitat selection over 20 years in Denali using vegetation maps from chapter 3, climate data and other environmental variables. Over the two-decade period, caribou selected middle elevation, open areas with high graminoid cover and earlier snow-free dates. As each winter progressed, caribou aggregated where there was higher lichen cover and earlier snow-melt. Caribou selected habitat differently between years, which I collapsed into three different habitat/year groups: (1) years where most animals were in low elevation, flat terrain where there was low lichen and conifer cover but high graminoid and shrub cover with variable snow; (2) years caribou went to middle elevations with deeper snow and rugged terrain and moderate graminoid and lichen cover; and (3) years where caribou were dispersed west in low elevation woodlands with high lichen cover. My results show interacting factors determine caribou habitat selection at multiple spatial scales, specifically the importance of open, tussock tundra and long-term trends in snow melt at long time scales and lichen and snow-melt at shorter time scales. This research improves our understanding of the regional distribution and abundance of lichens in relation to higher plants, fire, and caribou. Title: Lichen communities and caribou habitat in Denali National Park and Preserve, Alaska, USA Author: Nelson, Peter, 1970- Lichens play many important roles in subarctic terrestrial ecosystems by fixing nitrogen, colonizing rock and gravel, stabilizing otherwise bare soil, adding significantly to vegetation biodiversity and serving as the primary food for caribou in the winter. In these chapters, I analyzed lichen community and ecological trait structure along environmental gradients, map lichens using some of their unique spectral properties to generate lichen maps and study caribou habitat selection patterns in relation to lichens and other habitat variables. Morphological and life history traits of lichens influence their ecological roles through physiological limitations imposed by their form and photobionts, the algal or cyanobacterial partner. In chapter 2, I analyzed the lichen traits in relationship to environmental gradients, other forms of vegetation and time since fire in Denali National Park and Preserve, Alaska. Lichens with different photobionts reached different maxima along environmental gradients, these corresponding to variable water availability or specific biotic factors thought to favor that photobiont. Green algal lichens were most abundant in the alpine whereas cyanolichens peaked where shrub cover increased. Tripartite lichens were most abundant in middle elevation, mossy areas. Lichen growthforms peaked along desiccation and water absorption gradients. Lichens with small vegetative propagules were most abundant in lowland forests. Recent fire favored simple, Cladonia-form lichens with soredia that grow on wood whereas erect branched fruticose lichens, the "reindeer lichens", had only partially recovered 20-100 years after fire. These results imply interacting forces of water regulation, dispersal and optimum conditions for photosynthesis drive lichen trait frequency and abundance. The fungal partner within the lichen symbiosis produces many unique compounds that are often brightly colored. Other studies have attempted to map lichens using their distinctive spectral properties but no study has yet to target specific lichen compounds in order to better model lichen cover. In chapter 3, I focused on one yellow lichen compound, usnic acid, as the target for modeling lichen cover using Landsat 7 ETM+ satellite data. Usnic lichen cover had non-linear relationships with the three best predictors; elevation, blue and near-infrared bandpasses. Using these three predictors, I generated an usnic lichen map for Denali, which I use in chapter 4 for analyzing caribou habitat selection. I also modeled and mapped other vegetation groups corresponding to caribou diet items used later. My results show that some lichens may be directly mapped from space by targeting this specific compound produced by the fungus. Caribou depend on lichens for up to 66% of their winter diet but other factors, such as snow, affect their access to the lichens. In chapter 4, I analyzed caribou habitat selection over 20 years in Denali using vegetation maps from chapter 3, climate data and other environmental variables. Over the two-decade period, caribou selected middle elevation, open areas with high graminoid cover and earlier snow-free dates. As each winter progressed, caribou aggregated where there was higher lichen cover and earlier snow-melt. Caribou selected habitat differently between years, which I collapsed into three different habitat/year groups: (1) years where most animals were in low elevation, flat terrain where there was low lichen and conifer cover but high graminoid and shrub cover with variable snow; (2) years caribou went to middle elevations with deeper snow and rugged terrain and moderate graminoid and lichen cover; and (3) years where caribou were dispersed west in low elevation woodlands with high lichen cover. My results show interacting factors determine caribou habitat selection at multiple spatial scales, specifically the importance of open, tussock tundra and long-term trends in snow melt at long time scales and lichen and snow-melt at shorter time scales. This research improves our understanding of the regional distribution and abundance of lichens in relation to higher plants, fire, and caribou. Close

• 48. [Article] Trends in cation, nitrogen, sulfate and hydrogen ion concentrations in precipitation in the United States and Europe from 1978 to 2010: a new look at an old problem

  This is an author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by Springer and can be found at: http://link.springer.com/journal/10533.

  Citation × Citation Citation Abstract Copy Title: Trends in cation, nitrogen, sulfate and hydrogen ion concentrations in precipitation in the United States and Europe from 1978 to 2010: a new look at an old problem Author: Lajtha, Kate, Jones, Julia This is an author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by Springer and can be found at: http://link.springer.com/journal/10533. Title: Trends in cation, nitrogen, sulfate and hydrogen ion concentrations in precipitation in the United States and Europe from 1978 to 2010: a new look at an old problem Author: Lajtha, Kate, Jones, Julia This is an author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by Springer and can be found at: http://link.springer.com/journal/10533. Close

• 49. [Article] Adapting to Climate Change on Western Public Lands: Addressing the Ecological Effects of Domestic, Wild, and Feral Ungulates

  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/XFBYe2

  Citation × Citation Citation Abstract Copy Title: Adapting to Climate Change on Western Public Lands: Addressing the Ecological Effects of Domestic, Wild, and Feral Ungulates Author: DellaSala, Dominick A., Donahue, Deborah L., Rhodes, Jonathan J., O'Brien, Mary H., Beschta, Robert L., Fleischner, Thomas L., Karr, James R., Deacon-Williams, Cindy 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/XFBYe2 Title: Adapting to Climate Change on Western Public Lands: Addressing the Ecological Effects of Domestic, Wild, and Feral Ungulates Author: DellaSala, Dominick A., Donahue, Deborah L., Rhodes, Jonathan J., O'Brien, Mary H., Beschta, Robert L., Fleischner, Thomas L., Karr, James R., Deacon-Williams, Cindy 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/XFBYe2 Close

• 50. [Article] Effects of forest management on fish habitat and macroinvertebrates in northeast Oregon streams

  This study describes streams in the Blue Mountains and Wallowa Mountains of Northeastern Oregon in order to characterize the interactions between the terrestrial and aquatic ecosystems and to determine ...

  Citation × Citation Citation Abstract Copy Title: Effects of forest management on fish habitat and macroinvertebrates in northeast Oregon streams Author: Carlson, Joan Y. This study describes streams in the Blue Mountains and Wallowa Mountains of Northeastern Oregon in order to characterize the interactions between the terrestrial and aquatic ecosystems and to determine how logging affects those relationships. Five stream reach pairs, each consisting of an undisturbed reach and a similar reach flowing through an area where the riparian zone had been logged, along with six additional undisturbed reaches were studied. The riparian stand, large woody debris, stream channel morphology and the benthic macroinvertebrate community were measured at each reach. Large woody debris volume ranged from 91.1 to 284.0 m³/ha and was greater in the logged reaches than undisturbed reaches. Stream channel morphology, as indicated by the pool-riffle ratio, in the logged reaches was not significantly different than undisturbed reaches and percent pool area was less than 30 percent in all reaches. Macroinvertebrate density ranged from 146.6 to 963.2 individuals/sample and was greater in the logged reach of each stream pair. Community diversity, as expressed by the Shannon-Wiener Diversity Index, at logged reaches was not significantly different from that at undisturbed reaches. Although some differences were found between logged stream reaches and undisturbed reaches, there was no indication that overall fish habitat was greatly diminished or improved as a result of logging. Title: Effects of forest management on fish habitat and macroinvertebrates in northeast Oregon streams Author: Carlson, Joan Y. This study describes streams in the Blue Mountains and Wallowa Mountains of Northeastern Oregon in order to characterize the interactions between the terrestrial and aquatic ecosystems and to determine how logging affects those relationships. Five stream reach pairs, each consisting of an undisturbed reach and a similar reach flowing through an area where the riparian zone had been logged, along with six additional undisturbed reaches were studied. The riparian stand, large woody debris, stream channel morphology and the benthic macroinvertebrate community were measured at each reach. Large woody debris volume ranged from 91.1 to 284.0 m³/ha and was greater in the logged reaches than undisturbed reaches. Stream channel morphology, as indicated by the pool-riffle ratio, in the logged reaches was not significantly different than undisturbed reaches and percent pool area was less than 30 percent in all reaches. Macroinvertebrate density ranged from 146.6 to 963.2 individuals/sample and was greater in the logged reach of each stream pair. Community diversity, as expressed by the Shannon-Wiener Diversity Index, at logged reaches was not significantly different from that at undisturbed reaches. Although some differences were found between logged stream reaches and undisturbed reaches, there was no indication that overall fish habitat was greatly diminished or improved as a result of logging. Close