Mesocosm experiment Cape Verde 2012: Data

Two 7-day mesocosm experiments were conducted in October 2012 at the Instituto Nacional de Desenvolvimento das Pescas (INDP), Mindelo, Cape Verde. Surface water was collected at night before the start of the respective experiment with RV Islândia south of São Vicente (16°44.4'N, 25°09.4'W) and transported to shore using four 600L food safe intermediate bulk containers. Sixteen mesocosm bags were distributed in four flow-through water baths and shaded with blue, transparent lids to approximately 20% of surface irradiation. Mesocosm bags were filled from the containers by gravity, using a submerged hose to minimize bubbles. The accurate volume inside the individual bags was calculated after addition of 1.5 mmol silicate and measuring the resulting silicate concentration. The volume ranged from 105.5 to 145 L. The experimental manipulation comprised addition of different amounts of inorganic N and P. In the first experiment, the P supply was changed at constant N supply in thirteen of the sixteen units, while in the second experiment the N supply was changed at constant P supply in twelve of the sixteen units. In addition to this, "cornerpoints" were chosen that were repeated during both experiments. Four cornerpoints should have been repeated, but setting the nutrient levels in one mesocosm was not succesfull and therefore this mesocosm also was set at the center point conditions. Experimental treatments were evenly distributed between the four water baths. Initial sampling of the mesocosms on day 1 of each run was conducted between 9:45 and 11:30. After nutrient manipulation, sampling was conducted on a daily basis between 09:00 and 10:30 for days 2 to 8.

Mesocosm experiment Cape Verde 2012: Setup

Two 7-day mesocosm experiments were conducted in October 2012 at the Instituto Nacional de Desenvolvimento das Pescas (INDP), Mindelo, Cape Verde. Surface water was collected at night before the start of the respective experiment with RV Islândia south of São Vicente (16°44.4'N, 25°09.4'W) and transported to shore using four 600L food safe intermediate bulk containers. Sixteen mesocosm bags were distributed in four flow-through water baths and shaded with blue, transparent lids to approximately 20% of surface irradiation. Mesocosm bags were filled from the containers by gravity, using a submerged hose to minimize bubbles. The accurate volume inside the individual bags was calculated after addition of 1.5 mmol silicate and measuring the resulting silicate concentration. The volume ranged from 105.5 to 145 L. The experimental manipulation comprised addition of different amounts of inorganic N and P. In the first experiment, the P supply was changed at constant N supply in thirteen of the sixteen units, while in the second experiment the N supply was changed at constant P supply in twelve of the sixteen units. In addition to this, "cornerpoints" were chosen that were repeated during both experiments. Four cornerpoints should have been repeated, but setting the nutrient levels in one mesocosm was not succesfull and therefore this mesocosm also was set at the center point conditions. Experimental treatments were evenly distributed between the four water baths. Initial sampling of the mesocosms on day 1 of each run was conducted between 9:45 and 11:30. After nutrient manipulation, sampling was conducted on a daily basis between 09:00 and 10:30 for days 2 to 8.

Mesocosm experiment Cape Verde 2012: Environmental conditions (PAR, cloud cover, pump)

Two 7-day mesocosm experiments were conducted in October 2012 at the Instituto Nacional de Desenvolvimento das Pescas (INDP), Mindelo, Cape Verde. Surface water was collected at night before the start of the respective experiment with RV Islândia south of São Vicente (16°44.4'N, 25°09.4'W) and transported to shore using four 600L food safe intermediate bulk containers. Sixteen mesocosm bags were distributed in four flow-through water baths and shaded with blue, transparent lids to approximately 20% of surface irradiation. Mesocosm bags were filled from the containers by gravity, using a submerged hose to minimize bubbles. The accurate volume inside the individual bags was calculated after addition of 1.5 mmol silicate and measuring the resulting silicate concentration. The volume ranged from 105.5 to 145 L. The experimental manipulation comprised addition of different amounts of inorganic N and P. In the first experiment, the P supply was changed at constant N supply in thirteen of the sixteen units, while in the second experiment the N supply was changed at constant P supply in twelve of the sixteen units. In addition to this, "cornerpoints" were chosen that were repeated during both experiments. Four cornerpoints should have been repeated, but setting the nutrient levels in one mesocosm was not succesfull and therefore this mesocosm also was set at the center point conditions. Experimental treatments were evenly distributed between the four water baths. Initial sampling of the mesocosms on day 1 of each run was conducted between 9:45 and 11:30. After nutrient manipulation, sampling was conducted on a daily basis between 09:00 and 10:30 for days 2 to 8.

Phytomass and soil carbon storage of different land cover classes in the Usa river basin

This study describes detailed partitioning of phytomass carbon (C) and soil organic carbon (SOC) for four study areas in discontinuous permafrost terrain, Northeast European Russia. The mean aboveground phytomass C storage is 0.7 kg C/m**2. Estimated landscape SOC storage in the four areas varies between 34.5 and 47.0 kg C/m**2 with LCC (land cover classification) upscaling and 32.5-49.0 kg C/m**2 with soil map upscaling. A nested upscaling approach using a Landsat thematic mapper land cover classification for the surrounding region provides estimates within 5 ± 5% of the local high-resolution estimates. Permafrost peat plateaus hold the majority of total and frozen SOC, especially in the more southern study areas. Burying of SOC through cryoturbation of O- or A-horizons contributes between 1% and 16% (mean 5%) of total landscape SOC. The effect of active layer deepening and thermokarst expansion on SOC remobilization is modeled for one of the four areas. The active layer thickness dynamics from 1980 to 2099 is modeled using a transient spatially distributed permafrost model and lateral expansion of peat plateau thermokarst lakes is simulated using geographic information system analyses. Active layer deepening is expected to increase the proportion of SOC affected by seasonal thawing from 29% to 58%. A lateral expansion of 30 m would increase the amount of SOC stored in thermokarst lakes/fens from 2% to 22% of all SOC. By the end of this century, active layer deepening will likely affect more SOC than thermokarst expansion, but the SOC stores vulnerable to thermokarst are less decomposed.

Neogene palaeoceanographic and palaeoclimatic events inferred from palynological data: Cape Basin off South Africa, ODP Leg 175

Sites 1085, 1086 and 1087 were drilled off South Africa during Ocean Drilling Program (ODP) Leg 175 to investigate the Benguela Current System. While previous studies have focused on reconstructing the Neogene palaeoceanographic and palaeoclimatic history of these sites, palynology has been largely ignored, except for the Late Pliocene and Quaternary. This study presents palynological data from the upper Middle Miocene to lower Upper Pliocene sediments in Holes 1085A, 1086A and 1087C that provide complementary information about the history of the area. Abundant and diverse marine palynomorphs (mainly dinoflagellate cysts), rare spores and pollen, and dispersed organic matter have been recovered. Multivariate statistical analysis of dispersed organic matter identified three palynofacies assemblages (A, B, C) in the most continuous hole (1085A), and they were defined primarily by amorphous organic matter (AOM), and to a lesser extent black debris, structured phytoclasts, degraded phytoclasts, and marine palynomorphs. Ecostratigraphic interpretation based on dinoflagellate cyst, spore-pollen and palynofacies data allowed us to identify several palaeoceanographic and palaeoclimatic signals. First, the late Middle Miocene was subtropical, and sediments contained the highest percentages of land-derived organic matter, even though they are rich in AOM (palynofacies assemblage A). Second, the Late Miocene was cool-temperate and characterized by periods of intensified upwelling, increase in productivity, abundant and diverse oceanic dinoflagellate cysts, and the highest percentages of AOM (palynofacies assemblage C). Third, the Early to early Late Pliocene was warm-temperate with some dry intervals (increase in grass pollen) and intensified upwelling. Fourth, the Neogene "carbonate crash" identified in other southern oceans was recognized in two palynofacies A samples in Hole 1085A that are nearly barren of dinoflagellate cysts: one Middle Miocene sample (590 mbsf, 13.62 Ma) and one Upper Miocene sample (355 mbsf, 6.5 Ma). Finally, the extremely low percentages of pollen suggest sparse vegetation on the adjacent landmass, and Namib desert conditions were already in existence during the late Middle Miocene.

Plant communities and soil chemistry of shrub-steppe and pine savannah grasslands in southern British Columbia, Canada

Habitat fragmentation alters the edges of remnant habitat patches. We examined changes in the plant community and soil in relation to distance from edge and edge type for shrub-steppe and pine savannah grasslands in southern British Columbia, Canada. Community composition showed significant nonlinear relationships with distance-to-edge more frequently at paved roads and fruit crops than at dirt roads or control sites (i.e., in the interior of grassland patches), with changes typically extending 25-30 m. More exotic species and fewer native species were found near edges, and edges showed decreased cryptogam cover and increased bare ground, especially near paved roads. The soil factors that best predicted compositional changes were soil pH and Cu/Mn at paved roads, soil pH and nitrogen at fruit crops, and soil resistance at dirt roads. Variation partitioning suggested that both direct (e.g., propagule pressure) and indirect (environmental change) factors mediated edge-related community changes, and provided evidence that nonlinear responses at developed edges were not due to natural gradients. Given the range of grassland patch sizes in this region (many patches 1-100 ha), the edge effects we observed represent a considerable loss of "core" habitat, which must be accounted for in conservation planning and site restoration.