Time filter

Source Type

Castellanos-Galindo G.A.,Leibniz Center for Tropical Marine Ecology | Castellanos-Galindo G.A.,Jorge Tadeo Lozano University, Bogotá | Castellanos-Galindo G.A.,University of Valle | Krumme U.,Jorge Tadeo Lozano University, Bogotá | Krumme U.,Federal Research Institute for Rural Areas
Marine Ecology Progress Series | Year: 2013

The global comparison of mangrove fish assemblages and their ecological equivalence by Sheaves (2012; Mar Ecol Prog Ser 461:137-149) presents useful novel information for this specific ecosystem faunal assemblage. This comparison, however, included only a single study from the tropical Eastern Pacific region (TEP), which was assigned to an Eastern Central Atlantic group. Here, we present data that supplement the analysis made by Sheaves and show that the taxonomic composition (at the family level) of the TEP mangrove fish fauna is considerably different from the Eastern Central Atlantic, and warrants a different classification. To characterize TEP mangrove fish fauna, we used the same descriptors as in Sheaves (2012) (i.e. % of families with widespread vs. restricted distributions, and their affinity with families characteristic of coral reefs). Based on our analysis, the estuarine mangrove fish assemblages from the Neotropical region (TEP and Western Central Atlantic) substantially differ-both taxonomically and functionally-from the ones at the West African coast (tropical Eastern Atlantic) so that overall, Sheaves' (2012) Eastern Central Atlantic group likely consists of 3 groups: TEP, Western Central Atlantic and tropical Eastern Atlantic. An examination of the relative abundance and biomass of fish families revealed striking differences in their representativeness, especially between Neotropical and tropical Eastern Atlantic assemblages. Therefore, further comparisons of ecological equivalence should use metrics with a higher ecological resolution (i.e. biomass) than the ones employed by Sheaves (2012), giving a more meaningful basis to compare mangrove fish assemblages worldwide. © Inter-Research 2013.


Seo J.-W.,University of Hamburg | Eckstein D.,University of Hamburg | Jalkanen R.,Finnish Forest Research Institute | Schmitt U.,Federal Research Institute for Rural Areas
Environmental and Experimental Botany | Year: 2011

Boreal forests are highly sensitive to climate and human impacts and therefore suitable as biological indicator for environmental changes. In this context, our study was aimed at getting deeper insight into the climate-dependence of the onset, intensity and end of wood formation of Scots pine during the growing season. We monitored the intra-annual growth dynamics of, on average, 42-year-old Scots pine trees over five consecutive years, 2000-2004, at two sites located 80 and 300. km south of the tree line in northern Finland. For that purpose, the cambium of the trees was weekly wounded with a pin and the resulting wound tissue, microscopically detectable in transverse thin-sections through the newly built wood, was taken as a time marker. During this 5-year study period, the intra-annual wood formation at the southern site was mainly positively associated with summer temperature. However, at the northern site such an association was either entirely missing or negative. At both sites, two thirds of the radial growth was produced within only 4 weeks from mid-June to mid-July, independent of whether the growing season started earlier or later. Moreover, we measured the widths of all tree rings from bark to pith (inter-annual growth) of the same study trees and assembled them to 51-year long tree-ring site chronologies. Since 1999, these two site chronologies - after having run fairly parallel over the preceding decades - were running in divergent directions thus corroborating our results derived from the intra-annual climate/growth analysis. Whereas the chronology of the southern site follows the average temperature of May and July very closely from 1961 up to 2004, the chronology of the northern site follows the July temperature, but only up to 1998, and from 1999 to 2004 is running just opposite to the distinctly rising July temperature. During the same period, there was - unlike in the years before - nearly no snow cover in May at the northern site, whereas at the southern site there was no change of the normally existing slight snow cover in May. This deviating weather situation may have led to a temperature-induced, temporary drought stress for the Scots pines at the northern site. © 2011 Elsevier B.V.


Groger J.P.,Federal Research Institute for Rural Areas | Groger J.P.,University of Rostock | Fogarty M.J.,National Oceanic and Atmospheric Administration
ICES Journal of Marine Science | Year: 2011

Climatic influences on Georges Bank cod recruitment were investigated using the North Atlantic Oscillation (NAO) as an index of atmospheric variability and the Atlantic Multidecadal Oscillation (AMO) as an index of sea surface temperature. A quantitative approach based on a simple Cushing-type stock-recruitment model was developed and extended to include climate influences using the technique of generalized transfer functions (ARIMAX modelling). This allowed the autoregressive nature of the interacting exogenous and endogenous processes to be taken into account. Based on two information criteria, the resulting best transfer function contains winter NAO with a lag of 3 years, annual AMO with a lag of 1 year (both as exogenous climate factors), loge(spawning-stock biomass) as a structural model component, plus two autoregressive parameters. The model is characterized by the smallest information criteria, 92% of explained recruitment variation (vs. 55% from the simple Cushing-type model), excellent forecasting behaviour, and all model assumptions being fulfilled. It is proposed that the model's recruitment hindcasts (ex post forecasts) and forecasts be incorporated into stock and risk assessments as well as management strategy evaluations, either as a climate-induced recruitment index for projections or as real forecasts to establish sustainable cod fisheries on Georges Bank conditioned by climate as a forcing factor. © 2011 International Council for the Exploration of the Sea. Published by Oxford Journals. All rights reserved.


Anderson T.-H.,Federal Research Institute for Rural Areas | Anderson T.-H.,Institute of Agroecology | Anderson T.-H.,Institute of Soil Biology | Domsch K.H.,Institute of Soil Biology
Soil Biology and Biochemistry | Year: 2010

In the 1980s ecosystem research projects were implemented world-wide since there was a pressing need to quantify the impacts of anthropogenic pollutants. Soil ecosystem analyses concentrated first on the quantification of the element and energy transfer between pools. Since mineralization of organic substrates and the release of nutrients and elements are due to the heterotrophic activity of the microbial decomposer compartment, this subsystem of terrestrial ecosystems gained importance. Direct microscopic observation methods were inadequate for the quantification of environmental impacts on the microflora. We adopted the maintenance requirement concept for the quantification of environmental impacts or stress effects on the soil microbial community. The paper gives a brief inside to the concept of maintenance from autecological studies and describes the underlying points which lead to our experimental approach of its application at the synecological level (i.e., microbial biomass as a single ecological entity) - a process which rested on long-term continuous research. © 2010 Elsevier Ltd.


Dhillon R.S.,CCS Haryana Agricultural University | von Wuehlisch G.,Federal Research Institute for Rural Areas
Biomass and Bioenergy | Year: 2013

Rising level of atmospheric CO2 and consequent global warming is evident. Global surface temperature have already increased by 0.8 °C over the 20th century and is projected to increase by 1.4-5.8 °C during the twenty-first century. The global warming will continue till atmospheric concentrations of the major greenhouse gases are stabilized. Among them, CO2 is mainly responsible and is expected to account for about 60% of the warming over the next century. This study reviews advances on causes and consequences of global climate change and its impact on nature and society. Renewable biomass has tremendous potential to mitigate the global warming. Renewable biomass is expected to play a multifunctional role including food production, source of energy and fodder, biodiversity conservation, yield of goods and services to the society as well as mitigation of the impact of climate change. The review highlights the different management and research strategies in forestry, agriculture, agroforestry and grasslands to mitigate the global warming. © 2012 Elsevier Ltd.


Neumann H.,Senckenberg Institute | Ehrich S.,Federal Research Institute for Rural Areas | Kroncke I.,Senckenberg Institute
Aquatic Invasions | Year: 2010

So far the angular crab Goneplax rhomboides (Linnaeus, 1758) was mostly a northeastern Atlantic and Mediterranean species and was quite rare in the North Sea where no evidence for sustainable populations existed. In 2008 and 2009 a total of 82 individuals of Goneplax rhomboides (Linnaeus, 1758) were found at 22 widespread locations in the southern North Sea indicating that this species is now well established in the area. © 2010 The Author(s).


Elsasser P.,Federal Research Institute for Rural Areas | Englert H.,Federal Research Institute for Rural Areas | Hamilton J.,University of York
Annals of Forest Research | Year: 2010

The article describes the results of a choice experiment aimed at valuing landscape benefits of different kinds of forests in NE Germany by using computer generated images. Preferences for broadleaved/mixed forests over conifers amount to 40-85 € per year and household, additional visual diversity has a monetary value of about 20 €/a. This is true for the summer aspect of forests only. The same experiment conducted with winter images reveals no general preference for broadleaves, whereas visual diversity is valued even higher under winter conditions.The results are part of a study which aimed at valuing the impacts of a regional forest conversion programme. Beyond landscape value, the valuation has covered recreational value, the value for climate protection as well as timber production value. The development of landscape values over time can compensate for diminished timber returns until about 2080; afterwards the balance becomes negative. Carbon values are relatively minor in comparison to landscape and timber values. © ICAS 2010.


Dirksmeyer W.,Federal Research Institute for Rural Areas
Acta Horticulturae | Year: 2012

Pesticides are intensively used in open field vegetable production. The use of low pesticide applications and non-chemical pest control technologies is limited. A stochastic bio-economic Monte Carlo simulation model permits the efficiency of alternative pest control methods to be identified in order to assess the likelihood that such technologies will be adopted. Data were collected from a field survey of 134 vegetable producers in Denmark, Germany and The Netherlands cultivating carrot, leek and onion. The analysis focuses on the main insect pests and on weeds. Simulation results for Germany show that controlling carrot flies by timing pesticide applications with warnings from the advisory service is more profitable than routine calendar spraying. Due to low onion fly infestation levels in Germany, neither seed coating nor the sterile male onion fly technique are profitable. Conversely, thresholdbased thrip control in leek production is less profitable than routine spraying, due to the greater control effectiveness of the latter. In all three countries, combined chemical-mechanical weed control using reduced herbicide rates is more efficient than the application of full rates or non-chemical weeding. It was found that the risk of low pesticide use technologies is not necessarily higher than that of routine pesticide applications. Since low pesticide use technologies are rarely applied in Germany, although such technologies are profitable, it can be assumed that path dependence in pest control in open field vegetable production exists.


Leischner B.,Federal Research Institute for Rural Areas | Elsasser P.,Federal Research Institute for Rural Areas
Landbauforschung Volkenrode | Year: 2010

The course is set for a REDD scheme to be integrated in a potential future climate agreement. For an accreditation of the corresponding emission reductions, a reference emission level needs to be set. In this paper, we compare four approaches for a REDD reference emission level, namely Compensated Reduction (CR), Compensated Con-servation (CC), Incentive Accounting (IA) and Corridor Approach (CA). The economic advantageousness of the four baseline approaches is compared in terms of generated credits for 84 Non-Annex-I countries. Referring to 1990 to 2000 as the hypothetical "reference period" and to 2000 to 2005 as the "commitment period" based on FAO data, we show which groups of countries would have benefitted most in economic terms by each of the four baseline approaches, and how the groups are characterized by eco-logical, economic and social indicators. The approach presented in this paper shows the amount of credits or debits which would have been generated if a REDD scheme had been already established. As a result, in the periods in focus, the group of countries which would have generated most credits under CR is that of those least developed countries (with regard to HDI) which have a high forest cover, whereas CC would have been most advantageous for countries which show a recent increase in their forest area. The presented approach shows which windfall effects would have had to be considered if a REDD scheme had already been established. Furthermore, the results imply that countries' individual characteristics correspond to the question of which different approaches might be the most favourable in terms of generation of credits. Finally, further potential objectives of a REDD regime other than the mere generation of credits are discussed.


Tom-Dery D.,University for Development Studies | Schroeder J.-M.,Federal Research Institute for Rural Areas
Journal of the Botanical Research Institute of Texas | Year: 2011

The objective of this study was to determine the regeneration potential of natural forest fragments in the dry semi-deciduous forest zone in the Ashanti region of Ghana. For this reason tree species abundance was studied in two distinct natural forest patches located within a teak plantation. The full sampling revealed a total of 224 individual trees bebnging to 26 species and 14 families. A regeneration study using a systematic sampling design recorded a total of 46 tree species from 18 tree families. The majority of the woody species in the remnant natural forest was represented by only a few tree species. About 52% of all mature and regenerating trees were pioneer species It could be concluded that the higher diversity among the regeneration is due to seed dispersal from outside by birds, mammals and wind. The remnant natural forests show high species abundance and can play an important role for the preservation of a floristic diversity in a converted landscape.

Loading Federal Research Institute for Rural Areas collaborators
Loading Federal Research Institute for Rural Areas collaborators