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Fischer A.,TU Munich | Jantsch M.C.,TU Munich | Muller-Kroehling S.,Bayerische Landesanstalt fur Wald und Forstwirtschaft
Allgemeine Forst- und Jagdzeitung | Year: 2014

We studied the effect of global warming on the flora (vascular plants, bryophytes) and fauna (carabid beetles, snails) of beech forest communities in Bavaria, Germany. Climatic effects on the vegetation were analyzed in a time-series comparison of relevés in five different study areas, with the first relevés carried out between 1949 and 1985 and the recent relevés in 2010 by performing a partial canonical correspondence analysis. On a Bavarian-wide temperature gradient the upper and lower bounds of the ecological amplitude of species were analyzed for vascular plant, bryophyte, carabid beetle and snail species by the response along the temperature gradient in a Generalized Linear Model. Modeling of the potential beech forest habitats was performed for the present climate (1971-2000) and the future climate WETTREG B1 scenario (2071-2100) assuming a moderate warming of 1.8 K. Floristic changes are evident in the time-series comparison. However, most changes can be attributed to an increased nitrogen availability in forest ecosystems and a changed forest management in the last decades. Temperature effects on the species composition of beech forests as a whole are statistically measureable, albeit small and still difficult to break down to single species. The reason is neither necessarily a limited importance of the temperature factor nor a too insignificant temperature increase up to date, but that forest plant species are mostly long-lived hence react to environmental change with delay. Also, consequences of a temperature increase may be buffered by a today's denser tree canopy. After extreme climatic events like droughts, however, floristic changes might occur fast. More mobile and annually developing species like ground beetles and to a lesser extent snails are expected to react faster to global warming than plants. Changes will become relevant for all beech and mixed beech forests and will not affect only the herb layer. Particularly in the tree layer significant changes in species composition are expected. In colder regions and higher elevations more tree species (Quercus petraea, Carpinus betulus, Prunus avium, Sorbus torminalis) will likely benefit and may be used as admixed species in beech forests in the future more than today. Picea abies, on the other hand, will have a diminished role as admixted species of beech forests. Source

Matos E.S.,TU Brandenburg | Freese D.,TU Brandenburg | Slazak A.,TU Brandenburg | Bachmann U.,Bayerische Landesanstalt fur Wald und Forstwirtschaft | And 3 more authors.
Journal of Plant Nutrition and Soil Science | Year: 2010

The objective of this work was to evaluate the C and N stocks and organic-C fractions in soil under mixed forest stands of Scots pine (Pinus sylvestris L.) and Sessile oak (Quercus petraea [Matt.] Liebl.) of different ages in NE Germany. Treatments consisted of pure pine (age 102 y), and pine (age 90-102 y) mixed with 10-, 35-, 106-, and 124-y-old oak trees. After sampling O layers, soils in the mineral layer were taken at two different depths (0-10 and 10-20 cm). Oak admixture did not affect total organic-C (TOC) and N stocks considering the different layers separately. However, when the sum of TOC stocks in the organic and mineral layers was considered, TOC stocks decreased with increasing in oak age (r2 = 0.58, p < 0.10). The microbial C (CMB) was not directly correlated with increase of oak age, however, it was positively related with presence of oak species. There was an increase in the percentage of the CMB-to-TOC ratio with increase of oak-tree ages. On average, light-fraction C (CLF) comprised 68% of the soil TOC in upper layer corresponding to the highest C pool in the upper layer. CLF and heavy-fraction C (CHF) were not directly affected by the admixture of oak trees in both layers. The CHF accounted on average for 30% and 59% of the TOC at 0-10 and 10-20 cm depths, respectively. Despite low clay contents in the studied soils, the differences in the DCB-extractable Fe and Al affected the concentrations of the CHF and TOC in the 10-20 cm layers (p < 0.05). Admixture of oak in pine stands contributed to reduce topsoil C stocks, probably due to higher soil organic matter turnover promoted by higher quality of oak litter. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Prietzel J.,TU Munich | Stetter U.,Bayerische Landesanstalt fur Wald und Forstwirtschaft
Forest Ecology and Management | Year: 2010

For two Scots pine (Pinus sylvestris) ecosystems in S Germany with different atmospheric N deposition (Pfaffenwinkel, intermediate N deposition; Pustert, large N deposition), the supply with phosphorus (P) has been monitored for unfertilized and fertilized plots over more than four decades by foliar analysis (1964-2007). Additionally, topsoil concentrations and stocks of total P and plant-available P (citric-acid-extractable phosphate) were quantified in 10-year intervals (1982/1984, 1994, 2004). At both sites, fertilization experiments, including the variants control, NPKMgCa + lime, PKMgCa + lime + introduction of lupine, corresponding to an addition of 75 and 90 kg ha-1 P in Pustert and Pfaffenwinkel, respectively had been established in 1964. Our study revealed different trends of the P nutritional status for the pines at the two sites during the recent four decades: At Pustert, elevated atmospheric N deposition together with small topsoil P pools resulted in significant deterioration of Scots pine P nutrition and in an increasingly unbalanced N/P nutrition. At Pfaffenwinkel a trend of improved P nutrition from 1964 to 1991 was replaced by an opposite trend in the most recent 15 years. For our study sites, which are characterized by acidic soils with thick O layers, the forest floor stock of citric-acid-extractable phosphate showed a strong and significant correlation with the P concentration in current-year pine foliage, and thus was an appropriate variable to predict the P nutritional status of the stands. Total P stocks as well as the concentrations of total P in the forest floor or in the mineral topsoil were poorly correlated with pine foliar P concentrations and thus inappropriate predictors of P nutrition. P fertilization in the 1960s sustainably improved the P nutritional status of the stands. At Pfaffenwinkel, foliar P concentrations and topsoil stocks of citric-acid-extractable phosphate were increased at the fertilized plots relative to the control plots even 40 years after fertilization; at Pustert, foliar P concentrations were increased for about 20 years. © 2010 Elsevier B.V. All rights reserved. Source

The article analyzes the challenges inherent to establishing a regional wood market balancing and presents a wood market balance for the German state of Bavaria for the years 2005, 2010 and 2012. Using the Bavarian wood energy market studies as basis, the study incorporates suggestions for improving the state's wood market balancing and creates a wood market balance for Bavaria in relation to wood use at the place of consumption (material and energy). Doing so the method avoids double counting. Wood consumption, for both material and energy use, has significantly increased in Bavaria since 2005 due in part to a substantial decline in exports and outflows from the German domestic market. At the same time, the proportion of wood consumed for materials compared to wood energy in Bavaria has clearly shifted away from material use. The proposed method for developing a wood market balance offers a tool for aggregating material use with respect to the finished product which can provide important information, not only on the wood market itself, but also on the role of wood use in climate change mitigation. This creates an opportunity for creating a carbon balance for wood consumption on a regional level. © DLV GmbH. Source

The article uses the Bavarian wood market balance as basis to provide a method to regionally quantify the contribution wood consumption makes to climate change mitigation and thus facilitates the monitoring of the timber industry's CO2-effect at a subnational level. The analysis determines the change in the carbon store of wood products and CO2-reduction effects through material and energy substitution from the Bavarian wood market balance for the years 2005, 2010 and 2012. To provide a comprehensive understanding of the forest-based sector's role in climate change mitigation, the study examines changes in the forest carbon store based on existing data (national forest inventory data) for the period 2002-2012 and incorporates the findings into the overall assessment. In 2012, the CO2-effect of the Bavarian forest-based sector was 18.1 million tons, 21 % higher than 2005. 20% of the CO2effect were attributed to an increase in the forest and wood carbon stock, 80% to substitution effects. 18,1 million tons of CO2 correspond to 23% of the state's total CO2-emissions in 2012. The increase between 2005 and 2012 is primarily due to the fact that Bavarian net exports of timber fell and to a significant reduction in outflow from the German domestic timber market. The consumption cascade, i. e. the use of wood first for material and then for energy, offers the greatest potential to increase the timber industry's positive CO2-effects. Thus, as forests increasingly transition towards hardwood species in the future, greater consumption of hardwood material will become an important goal not only for economic reasons, but also with respect to the timber industry's role in reducing CO2. © DLV GmbH. Source

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