Tree-based intercropping: a land use for greenhouse gas mitigation in canadian agricultural systems

PosterIn tree-based intercropping (TBI) systems, the potential influence of trees in relation to carbon (C ) sequestration and Greenhouse Gas (GHG) emissions reduction has been documented but the mechanisms, remain poorly understood, especially for below-ground processes. Recently, several studies in this area were undertaken in Ontario, Canada under the auspices of Canada’s involvement in the Global Research Alliance. C sequestration potential, nitrous oxide reduction potential and soil voids were quantified in a 25-year-old TBI system in southern Ontario for five tree species: hybrid poplar (Populus spp.), Norway spruce (Picae abies), red oak (Quercus rubra), black walnut (Juglans nigra), and white cedar (Thuja occidentalis) which were intercropped with soybean (Glycine max). Results were compared with a conventional agricultural system in which soybean was grown as the sole crop. The net C flux for poplar, spruce, oak, walnut, cedar and the soybean sole-crop were + 2.1, + 1.6, + 0.8, + 1.8, +1.4 and – 1.2 t C ha-1, y-1, respectively. The results suggest a greater atmospheric CO2 sequestration potential for all five tree species when compared to a conventional agricultural system. DNA was also extracted from soil cores collected around four of the tree species (walnut, red oak, Norway spruce, poplar) and used for quantitative real-time PCR to determine the abundance of key functional genes in the nitrification and denitrification pathways. Results indicate that both tree species and proximity to the tree, can influence the abundance of key microbial groups associated with N2O production, particularly organisms associated with denitrification, nosZ and nirS. Soil void analysis showed that there was a positive correlation between x-ray bulk radio-density and soil bulk density, and a negative correlation between mean intra-aggregate x-ray radio-density and soil organic carbon (rs=-0.48, p=0.033), suggesting that the X-ray CT method could therefore be used to predict these soil properties

Tree-based intercropping: a land use for greenhouse gas mitigation in canadian agricultural systems

PosterIn tree-based intercropping (TBI) systems, the potential influence of trees in relation to carbon (C ) sequestration and Greenhouse Gas (GHG) emissions reduction has been documented but the mechanisms, remain poorly understood, especially for below-ground processes. Recently, several studies in this area were undertaken in Ontario, Canada under the auspices of Canada’s involvement in the Global Research Alliance. C sequestration potential, nitrous oxide reduction potential and soil voids were quantified in a 25-year-old TBI system in southern Ontario for five tree species: hybrid poplar (Populus spp.), Norway spruce (Picae abies), red oak (Quercus rubra), black walnut (Juglans nigra), and white cedar (Thuja occidentalis) which were intercropped with soybean (Glycine max). Results were compared with a conventional agricultural system in which soybean was grown as the sole crop. The net C flux for poplar, spruce, oak, walnut, cedar and the soybean sole-crop were + 2.1, + 1.6, + 0.8, + 1.8, +1.4 and – 1.2 t C ha-1, y-1, respectively. The results suggest a greater atmospheric CO2 sequestration potential for all five tree species when compared to a conventional agricultural system. DNA was also extracted from soil cores collected around four of the tree species (walnut, red oak, Norway spruce, poplar) and used for quantitative real-time PCR to determine the abundance of key functional genes in the nitrification and denitrification pathways. Results indicate that both tree species and proximity to the tree, can influence the abundance of key microbial groups associated with N2O production, particularly organisms associated with denitrification, nosZ and nirS. Soil void analysis showed that there was a positive correlation between x-ray bulk radio-density and soil bulk density, and a negative correlation between mean intra-aggregate x-ray radio-density and soil organic carbon (rs=-0.48, p=0.033), suggesting that the X-ray CT method could therefore be used to predict these soil properties

Tree-based intercropping: a land use for greenhouse gas mitigation in canadian agricultural systems

PosterIn tree-based intercropping (TBI) systems, the potential influence of trees in relation to carbon (C ) sequestration and Greenhouse Gas (GHG) emissions reduction has been documented but the mechanisms, remain poorly understood, especially for below-ground processes. Recently, several studies in this area were undertaken in Ontario, Canada under the auspices of Canada’s involvement in the Global Research Alliance. C sequestration potential, nitrous oxide reduction potential and soil voids were quantified in a 25-year-old TBI system in southern Ontario for five tree species: hybrid poplar (Populus spp.), Norway spruce (Picae abies), red oak (Quercus rubra), black walnut (Juglans nigra), and white cedar (Thuja occidentalis) which were intercropped with soybean (Glycine max). Results were compared with a conventional agricultural system in which soybean was grown as the sole crop. The net C flux for poplar, spruce, oak, walnut, cedar and the soybean sole-crop were + 2.1, + 1.6, + 0.8, + 1.8, +1.4 and – 1.2 t C ha-1, y-1, respectively. The results suggest a greater atmospheric CO2 sequestration potential for all five tree species when compared to a conventional agricultural system. DNA was also extracted from soil cores collected around four of the tree species (walnut, red oak, Norway spruce, poplar) and used for quantitative real-time PCR to determine the abundance of key functional genes in the nitrification and denitrification pathways. Results indicate that both tree species and proximity to the tree, can influence the abundance of key microbial groups associated with N2O production, particularly organisms associated with denitrification, nosZ and nirS. Soil void analysis showed that there was a positive correlation between x-ray bulk radio-density and soil bulk density, and a negative correlation between mean intra-aggregate x-ray radio-density and soil organic carbon (rs=-0.48, p=0.033), suggesting that the X-ray CT method could therefore be used to predict these soil properties

Small bowel gastrointestinal stromal tumours and ampullary cancer in Type 1 neurofibromatosis

BACKGROUND: Type 1 neurofibromatosis (NF-1) is an autosomal dominant disorder with variable penetrance; approximately 50% of cases present as new mutations CASE REPORT: We report a case of a 56 year-old man with Von Recklinghausen's disease, carcinoma of the ampulla of Vater and incidental benign gastrointestinal stromal tumours of the jejunum. CONCLUSIONS: Coexistence between ampullary carcinoid, ectopic pancreatic tissue in the jejunum and neurofibroma of the jejunum in NF-1 has been previously described however; the association of synchronous carcinoma of the ampulla of Vater and gastrointestinal stromal tumour of the jejunum in NF-1 has not been previously reported

Breeding latitude predicts timing but not rate of spring migration in a widespread migratory bird in South America

Identifying the processes that determine avian migratory strategies in different environmental contexts is imperative to understanding the constraints to survival and reproduction faced by migratory birds across the planet. We compared the spring migration strategies of Fork‐tailed Flycatchers (Tyrannus s. savana) that breed at south‐temperate latitudes (i.e., austral migrants) vs. tropical latitudes (i.e., intratropical migrants) in South America. We hypothesized that austral migrant flycatchers are more time‐selected than intratropical migrants during spring migration. As such, we predicted that austral migrants, which migrate further than intratropical migrants, will migrate at a faster rate and that the rate of migration for austral migrants will be positively correlated with the onset of spring migration. We attached light‐level geolocators to Fork‐tailed Flycatchers at two tropical breeding sites in Brazil and at two south‐temperate breeding sites in Argentina and tracked their movements until the following breeding season. Of 286 geolocators that were deployed, 37 were recovered ~1 year later, of which 28 provided useable data. Rate of spring migration did not differ significantly between the two groups, and only at one site was there a significantly positive relationship between date of initiation of spring migration and arrival date. This represents the first comparison of individual migratory strategies among conspecific passerines breeding at tropical vs. temperate latitudes and suggests that austral migrant Fork‐tailed Flycatchers in South America are not more time‐selected on spring migration than intratropical migrant conspecifics. Low sample sizes could have diminished our power to detect differences (e.g., between sexes), such that further research into the mechanisms underpinning migratory strategies in this poorly understood system is necessary.Fil: Jahn, Alex. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Cereghetti, Joaquín. Universidad Nacional de La Pampa; ArgentinaFil: Cueto, Víctor. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Centro de Investigación Esquel de Montaña y Estepa Patagóica. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ciencias Naturales - Sede Esquel. Centro de Investigación Esquel de Montaña y Estepa Patagónica; ArgentinaFil: Hallworth, Michael T.. Smithsonian Conservation Biology Institute; Estados UnidosFil: Levey, Douglas J.. National Science Foundation; Estados UnidosFil: Marini, Miguel Â.. Universidade do Brasília; BrasilFil: Masson, Diego. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; ArgentinaFil: Pizo, Marco A.. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Sarasola, José Hernán. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencias de la Tierra y Ambientales de La Pampa. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Instituto de Ciencias de la Tierra y Ambientales de La Pampa; ArgentinaFil: Tuero, Diego Tomas. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentin

Development of deep Vs profiles and site periods for the Canterbury region

Recent field investigations were carried out to define the shear wave velocity (VS) profile and site periods across the Canterbury region, supplementing earlier efforts in urban Christchurch. Active source surface wave testing, ambient wave field (passive) and H/V spectral ratio methods were used to characterise the soil profile in the region. H/V spectral ratio peaks indicate site periods in the range of 5-7 seconds across much of the Canterbury Plains, broadly consistent with those based on a 1D velocity model for the region. Site periods decrease rapidly in the vicinity of the Canterbury foothills and the Banks Peninsula outcrops. In Christchurch, the Riccarton Gravels result in a significant mode of vibration that has a much shorter period than the site period of the entire soil column down to basement rock