The Experts below are selected from a list of 6123 Experts worldwide ranked by ideXlab platform
Jose Leonardo De Moraes Goncalves - One of the best experts on this subject based on the ideXlab platform.
-
partitioning of net primary Production in eucalyptus and acacia stands and in mixed species plantations two case studies in contrasting tropical environments
Forest Ecology and Management, 2013Co-Authors: Daniel Epron, Louis Mareschal, Jean-paul Laclau, Yann Nouvellon, Rildo Moreira E Moreira, Lydiestella Koutika, Blandine Geneste, Juan Sinforiano Delgadorojas, Gael Sola, Jose Leonardo De Moraes GoncalvesAbstract:The introduction of nitrogen fixing species (NFS) in fast-growing tree plantations is an alternative option to reduce fertilizer inputs. However, the success of mixed-species plantations depends on the balance between positive interactions among species (resulting from facilitation and/or complementarity) and the negative effects of interspecific competition. Using a carbon budget approach and coupling measurements of standing biomass, aboveground litterfall and soil CO2 efflux, we assessed the influence of replacing half of eucalypt trees by Acacia mangium on total Belowground carbon flux (TBCF), net primary Production (NPP) and its partitioning between above- and Belowground growth at two tropical sites in Brazil (Itatinga) and in Congo (Kissoko) exhibiting contrasting climates, edaphic conditions and wood Productions. Annual soil CO2 efflux (F-S) was significantly lower in the acacia monocultures than in eucalypt monocultures and mixed-species stands at both sites. Annual F-S was significantly lower at Itatinga compared to Kissoko for all stands while TBCF was significantly lower in the eucalypt stands only. In the eucalypt monocultures we found a significantly lower aboveground NPP (ANPP) and wood Production (wood NPP) at Kissoko compared to Itatinga that was almost fully balanced by a significantly higher Belowground NPP (BNPP), leading to similar NPP. Similarly, acacia monocultures exhibited significantly higher ANPP and wood NPP at Itatinga than at Kissoko. The mixed-species stands exhibited a significantly lower wood NPP and ANPP than the eucalypt monocultures at the Brazilian site while NPP of the mixture was not significantly different than the average NPP of the two monocultures. At the Congolese site, NPP of the mixture was significantly higher than the average NPP of the two monocultures. NPP was similar in the mixed-species stand and the eucalypt monoculture with a significantly lower partitioning of NPP to Belowground Production, leading to a one third higher wood biomass at harvest in the mixed-species stand. A positive effect of growing eucalypts with the nitrogen fixing acacia trees on stand wood Production occurred at Kissoko but not at Itatinga. Mixed-species plantations with NFS can be advocated at sites where the productive gains resulting from nitrogen fixation are not compromised by other resource limitations. (c) 2012 Elsevier B.V. All rights reserved.
-
Partitioning of net primary Production in Eucalyptus and Acacia stands and in mixed-species plantations: Two case-studies in contrasting tropical environments
Forest Ecology and Management, 2013Co-Authors: Daniel Epron, Louis Mareschal, Jean-paul Laclau, Yann Nouvellon, Lydiestella Koutika, Blandine Geneste, Gael Sola, Rildo Moreira E Moreira, Juan Sinforiano Delgado-rojas, Jose Leonardo De Moraes GoncalvesAbstract:The introduction of nitrogen fixing species (NFS) in fast-growing tree plantations is an alternative option to reduce fertilizer inputs. However, the success of mixed-species plantations depends on the balance between positive interactions among species (resulting from facilitation and/or complementarity) and the negative effects of interspecific competition. Using a carbon budget approach and coupling measurements of standing biomass, aboveground litterfall and soil CO2 efflux, we assessed the influence of replacing half of eucalypt trees by Acacia mangium on total Belowground carbon flux (TBCF), net primary Production (NPP) and its partitioning between above- and Belowground growth at two tropical sites in Brazil (Itatinga) and in Congo (Kissoko) exhibiting contrasting climates, edaphic conditions and wood Productions. Annual soil CO2 efflux (F-S) was significantly lower in the acacia monocultures than in eucalypt monocultures and mixed-species stands at both sites. Annual F-S was significantly lower at Itatinga compared to Kissoko for all stands while TBCF was significantly lower in the eucalypt stands only. In the eucalypt monocultures we found a significantly lower aboveground NPP (ANPP) and wood Production (wood NPP) at Kissoko compared to Itatinga that was almost fully balanced by a significantly higher Belowground NPP (BNPP), leading to similar NPP. Similarly, acacia monocultures exhibited significantly higher ANPP and wood NPP at Itatinga than at Kissoko. The mixed-species stands exhibited a significantly lower wood NPP and ANPP than the eucalypt monocultures at the Brazilian site while NPP of the mixture was not significantly different than the average NPP of the two monocultures. At the Congolese site, NPP of the mixture was significantly higher than the average NPP of the two monocultures. NPP was similar in the mixed-species stand and the eucalypt monoculture with a significantly lower partitioning of NPP to Belowground Production, leading to a one third higher wood biomass at harvest in the mixed-species stand. A positive effect of growing eucalypts with the nitrogen fixing acacia trees on stand wood Production occurred at Kissoko but not at Itatinga. Mixed-species plantations with NFS can be advocated at sites where the productive gains resulting from nitrogen fixation are not compromised by other resource limitations.
Robert W. Mccomas - One of the best experts on this subject based on the ideXlab platform.
-
A Landscape-Scale Assessment of Above- and Belowground Primary Production in Coastal Wetlands: Implications for Climate Change-Induced Community Shifts
Estuaries and Coasts, 2017Co-Authors: Camille L. Stagg, Sarai C. Piazza, Gregg Snedden, Gregory D. Steyer, Craig J. Fischenich, Donald R. Schoolmaster, Robert W. MccomasAbstract:Above-and Belowground Production in coastal wetlands are important contributors to carbon accumulation and ecosystem sustainability. As sea level rises, we can expect shifts to more salt-tolerant communities, which may alter these ecosystem functions and services. Although the direct influence of salinity on species-level primary Production has been documented, we lack an understanding of the landscape-level response of coastal wetlands to increasing salinity. What are the indirect effects of sea-level rise, i.e., how does primary Production vary across a landscape gradient of increasing sa-linity that incorporates changes in wetland type? This is the first study to measure both above-and Belowground Production in four wetland types that span an entire coastal gradient from fresh to saline wetlands. We hypothesized that increasing salinity would limit rates of primary Production, and saline marshes would have lower rates of above-and Belowground Production than fresher marshes. However, along the Northern Gulf of Mexico Coast in Louisiana, USA, we found that aboveground Production was highest in brackish marshes, compared with fresh, intermediate, and saline marshes, and Belowground Production was similar among all wetland types along the salinity gradient. Multiple regression analysis indicated that salinity was the only significant predictor of Production, and its influence was dependent upon wetland type. We concluded that (1) salinity had a negative effect on Production within wetland type, and this relationship was strongest in the fresh marsh (0-2 PSU) and (2) along the overall landscape gradient, Production was maintained by mechanisms at the scale of wetland type, which were likely related to plant energetics. Regardless of wetland type, we found that Belowground Production was significantly greater than aboveground Production. Additionally, inter-annual variation , associated with severe drought conditions, was observed exclusively for Belowground Production, which may be a more sensitive indicator of ecosystem health than above-ground Production.
Daniel Epron - One of the best experts on this subject based on the ideXlab platform.
-
partitioning of net primary Production in eucalyptus and acacia stands and in mixed species plantations two case studies in contrasting tropical environments
Forest Ecology and Management, 2013Co-Authors: Daniel Epron, Louis Mareschal, Jean-paul Laclau, Yann Nouvellon, Rildo Moreira E Moreira, Lydiestella Koutika, Blandine Geneste, Juan Sinforiano Delgadorojas, Gael Sola, Jose Leonardo De Moraes GoncalvesAbstract:The introduction of nitrogen fixing species (NFS) in fast-growing tree plantations is an alternative option to reduce fertilizer inputs. However, the success of mixed-species plantations depends on the balance between positive interactions among species (resulting from facilitation and/or complementarity) and the negative effects of interspecific competition. Using a carbon budget approach and coupling measurements of standing biomass, aboveground litterfall and soil CO2 efflux, we assessed the influence of replacing half of eucalypt trees by Acacia mangium on total Belowground carbon flux (TBCF), net primary Production (NPP) and its partitioning between above- and Belowground growth at two tropical sites in Brazil (Itatinga) and in Congo (Kissoko) exhibiting contrasting climates, edaphic conditions and wood Productions. Annual soil CO2 efflux (F-S) was significantly lower in the acacia monocultures than in eucalypt monocultures and mixed-species stands at both sites. Annual F-S was significantly lower at Itatinga compared to Kissoko for all stands while TBCF was significantly lower in the eucalypt stands only. In the eucalypt monocultures we found a significantly lower aboveground NPP (ANPP) and wood Production (wood NPP) at Kissoko compared to Itatinga that was almost fully balanced by a significantly higher Belowground NPP (BNPP), leading to similar NPP. Similarly, acacia monocultures exhibited significantly higher ANPP and wood NPP at Itatinga than at Kissoko. The mixed-species stands exhibited a significantly lower wood NPP and ANPP than the eucalypt monocultures at the Brazilian site while NPP of the mixture was not significantly different than the average NPP of the two monocultures. At the Congolese site, NPP of the mixture was significantly higher than the average NPP of the two monocultures. NPP was similar in the mixed-species stand and the eucalypt monoculture with a significantly lower partitioning of NPP to Belowground Production, leading to a one third higher wood biomass at harvest in the mixed-species stand. A positive effect of growing eucalypts with the nitrogen fixing acacia trees on stand wood Production occurred at Kissoko but not at Itatinga. Mixed-species plantations with NFS can be advocated at sites where the productive gains resulting from nitrogen fixation are not compromised by other resource limitations. (c) 2012 Elsevier B.V. All rights reserved.
-
Partitioning of net primary Production in Eucalyptus and Acacia stands and in mixed-species plantations: Two case-studies in contrasting tropical environments
Forest Ecology and Management, 2013Co-Authors: Daniel Epron, Louis Mareschal, Jean-paul Laclau, Yann Nouvellon, Lydiestella Koutika, Blandine Geneste, Gael Sola, Rildo Moreira E Moreira, Juan Sinforiano Delgado-rojas, Jose Leonardo De Moraes GoncalvesAbstract:The introduction of nitrogen fixing species (NFS) in fast-growing tree plantations is an alternative option to reduce fertilizer inputs. However, the success of mixed-species plantations depends on the balance between positive interactions among species (resulting from facilitation and/or complementarity) and the negative effects of interspecific competition. Using a carbon budget approach and coupling measurements of standing biomass, aboveground litterfall and soil CO2 efflux, we assessed the influence of replacing half of eucalypt trees by Acacia mangium on total Belowground carbon flux (TBCF), net primary Production (NPP) and its partitioning between above- and Belowground growth at two tropical sites in Brazil (Itatinga) and in Congo (Kissoko) exhibiting contrasting climates, edaphic conditions and wood Productions. Annual soil CO2 efflux (F-S) was significantly lower in the acacia monocultures than in eucalypt monocultures and mixed-species stands at both sites. Annual F-S was significantly lower at Itatinga compared to Kissoko for all stands while TBCF was significantly lower in the eucalypt stands only. In the eucalypt monocultures we found a significantly lower aboveground NPP (ANPP) and wood Production (wood NPP) at Kissoko compared to Itatinga that was almost fully balanced by a significantly higher Belowground NPP (BNPP), leading to similar NPP. Similarly, acacia monocultures exhibited significantly higher ANPP and wood NPP at Itatinga than at Kissoko. The mixed-species stands exhibited a significantly lower wood NPP and ANPP than the eucalypt monocultures at the Brazilian site while NPP of the mixture was not significantly different than the average NPP of the two monocultures. At the Congolese site, NPP of the mixture was significantly higher than the average NPP of the two monocultures. NPP was similar in the mixed-species stand and the eucalypt monoculture with a significantly lower partitioning of NPP to Belowground Production, leading to a one third higher wood biomass at harvest in the mixed-species stand. A positive effect of growing eucalypts with the nitrogen fixing acacia trees on stand wood Production occurred at Kissoko but not at Itatinga. Mixed-species plantations with NFS can be advocated at sites where the productive gains resulting from nitrogen fixation are not compromised by other resource limitations.
Dale Goehringer D Tonerb - One of the best experts on this subject based on the ideXlab platform.
-
salt marshes and eutrophication an unsustainable outcome
Limnology and Oceanography, 2009Co-Authors: Eugene R Turner, Erick M. Swenson, Charles S. Milan, John M. Teal, Brian L Howes, Dale Goehringer D TonerbAbstract:Most plant Production by emergent coastal marshes occurs Belowground. This Belowground Production adds to the accumulation of organic matter sustaining salt marshes as sea level rises, thus preventing excessive flooding, eventual plant death, and habitat loss. The ubiquitous nutrient enrichment of coastal salt marshes stimulating aboveground plant growth may result in higher rates of inorganic matter accumulation that compensates for marsh flooding caused by sea level rise. Results from several short-term experiments, however, demonstrate that root and rhizome biomass and carbon accumulation is reduced with nutrient enrichment, suggesting that eutrophication of coastal waters may not be a compensatory counterbalance to the effects of global sea level rise on salt marshes. We show that the net effects of 36 yr of nutrient enrichment in replicated field experiments do not lead to higher organic or inorganic accumulation. Enrichment reduces organic matter Belowground and may result in a significant loss in marsh elevation equivalent to about half the average global sea level rise rates. Sustaining and restoring coastal emergent marshes is more likely if they receive less, not more, nutrient loading.
Shimon C Anisfeld - One of the best experts on this subject based on the ideXlab platform.
-
coastal wetland response to sea level rise in connecticut and new york
Estuarine Coastal and Shelf Science, 2015Co-Authors: Troy D Hill, Shimon C AnisfeldAbstract:Abstract The persistence of salt marshes in the landscape depends on their ability to accommodate rising sea level and minimize additional flooding stress. We use sediment cores and water level data from 14 marshes in Connecticut and New York to evaluate how marsh accretion, mineral and organic accumulation, carbon storage, and hydroperiod have changed from 1900 to 2012. We observe a regional acceleration in marsh accretion beginning around 1940, although marsh accretion did not reach parity with sea level rise for several additional decades. Despite a rise in marsh accretion from 1.0 mm yr−1 circa 1900 to 3.6 mm yr−1 at present, the marsh surface has lost elevation relative to tidal datums. Declining relative elevations have led to increased tidal flooding, particularly in high marsh settings. As flooding increased, organic matter accumulation accelerated at all marshes. Accelerating mineral deposition was only observed in areas of short-form Spartina alterniflora. Mineral and organic sediment accumulation co-limit accretion, but organic accumulation was the stronger limiting factor, suggesting that marsh response to sea level rise in the region is sensitive to processes affecting rates of Belowground Production and decomposition. Marsh carbon storage over the period of study averaged 84 g C m−2 yr−1, increasing as accretion accelerated. If marshes remain spatially intact as sea levels rise, these results suggest that marshes have the capacity to become even greater C sinks.