Die Ausbildung des Forstpersonales in Baden

Ohne Zusammenfassung     

Soil carbon, nitrogen, pH, and earthworm density as influenced by cropping practices in the Inland Pacific Northwest

Farmers within the Inland Pacific Northwest are gradually transitioning to direct seed (DS) practices that reduce soil disturbance and increase surface residue compared to conventional tillage (CT). Despite this transition the impacts of DS practices on soil properties and fauna in commercial fields has been little studied in the region. During the spring and summer of 2002 and 2003 we compared soil organic carbon (SOC), total nitrogen (TN), pH, and earthworm and cocoon densities in CT and DS fields planted to either spring wheat or pea in the Palouse region of northern Idaho. In 2002 mean SOC within the 0–10-cm depth was greater in DS fields (2.05%) than at the same depth in CT fields (1.79%), however SOC within the 30–40-cm depth was lower under DS compared to CT. Mean soil pH within the 0–10-cm depth was 5.35 under DS and 5.61 under CT indicating that pH stratification can occur when tillage is reduced. Tillage effects on SOC, TN, and pH were not found in 2003. Tillage also did not significantly influence earthworm densities, which averaged 39 individuals m⁻² in 2002 and 57 individuals m⁻² in 2003. Correlations were detected in 2003 DS fields between soil properties (SOC and TN) and earthworm and cocoon densities at depths above 30 cm while in 2002 correlations in DS fields occurred with cocoon density, but not with earthworm density. Direct seed management can increase near-surface SOC and TN concentrations compared to CT practices, however, SOC concentrations deeper in the soil appear to remain the same or possibly decrease. Higher SOC and TN near the soil surface, as found in DS fields, appear to promote greater earthworm densities, which may improve long-term soil productivity.     

Characterization of soil profiles and elemental concentrations reveals deposition of heavy metals and phosphorus in a Chicago-area nature preserve,Gensburg Markham Prairie

Purpose

Gensburg Markham Prairie (GMP), a high-quality tallgrass prairie and wetland in the Chicago area, is surrounded by high-traffic highways and residential communities. Anthropogenic inputs are a concern given observed ecosystem degradation around the periphery of the prairie. To understand soil quality and the potential for habitat degradation in GMP, we evaluated concentrations of metals and phosphorus in soil profiles, identified possible sources of contamination, and assessed the likelihood that contamination would impact the prairie ecosystem.

Materials and methods

We collected 15 intact soil cores (to a depth of 120 cm) and 22 surface soil samples (0–10-cm depth), determined the soil type, and measured pH, organic matter, and concentrations of Pb, Cu, Zn, Mg, Fe, K, Ca, and P using ICP-OES. To quantify soil pollution, we calculated the element enrichment factor (EF) and single element pollution index (SEPI) for each sample. We also used principal component analysis (PCA) to interpret relationships between site variables, elemental concentrations, and sources of metals.

Results and discussion

Heavy metals (Pb, Cu, and Zn) and P were found to accumulate in surface samples. The mean EF values for Pb, Cu, Zn, and P revealed significant enrichment of these elements in the soil profiles. However, SEPI analyses indicate that GMP soils have a low level of contamination. PCA revealed that concentrations are highest for samples with high organic matter content near the ground surface and that Pb, Cu, and Zn have common sources of pollution.

Conclusions

We observed enrichment of Pb, Cu, Zn, and P because of deposition from the urban built environment, but the enrichment levels are low enough that they are not expected to negatively impact the ecosystem of GMP. The detailed soil chemistry data constitute a spatial contamination map that can be used to assess potential long-term impacts on the ecosystem, such as reduction of plant growth and species diversity, and inform site management and biodiversity conservation efforts.

     

Taxonomical study into two new species of Philometra (Nematoda: Philometridae) previously identified as Philometra lateolabracis (Yamaguti, 1935)

Males of the nematode Philometra lateolabracis (Yamaguti, 1935), the type species of the genus Philometra Costa, 1845, were discovered for the first time in gonads of its type host, the Japanese seaperch, Lateolabraxjaponicus (Cuvier). Morphological comparisons carried out between the collected male and female P. lateolabracis with the male and female philometrid nematodes previously reported as P. lateolabracis infecting chicken grunt, Parapristipoma trilineatum (Thunberg), and red sea bream, Pagrus major (Temminck et Schlegel), revealed that the latter represent two new species, Philometra isaki sp. n. and Philometra madai sp. n., respectively. Molecular comparison of ITS2 rDNA between P. lateolabracis and P. madai supported the morphological conclusion that the two nematodes obtained from different fish species should be assigned to different species.     

Integration of Northern spotted owl habitat and fuels treatments in the eastern Cascades,Washington, USA

The restoration of natural fire regimes has emerged as a primary management objective within fire-prone forests in the interior western US. However, this objective becomes contentious when perceived to be in conflict with the conservation of rare wildlife species. For example, the integration of fire ecology in disturbance-prone forests of eastern Washington with the recovery of the Northern spotted owl has been described as a management dilemma. We intersected modeled spotted owl habitat with mapped priority fuels treatment areas in order to determine the magnitude of the potential conflict between fuels management and owl conservation. Our results show that there is considerable overlap within dry forests between high suitability spotted owl habitat and moderate-high priority fuels treatment areas (34% overlap). However, there is also considerable overlap of lower suitability spotted owl habitat with moderate-high priority fuels treatment areas (35% overlap) providing opportunities to accomplish multiple management objectives if one considers a landscape perspective. We propose that a conservation strategy for the Northern spotted owl in the eastern Cascades consider the following: emphasize landscape restoration of dry forests within which spotted owl habitat is embedded; landscapes considered for restoration need to be large enough to accomodate the effects of fire disturbances and still retain sufficient habitat to support spotted owl populations; and include adaptive management allowing for adequate monitoring and feedback for managers to make needed adjustments.