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1.
Matilda Palm Madelene Ostwald Indu K. Murthy Rajiv K. Chaturvedi N. H. Ravindranath 《Regional Environmental Change》2011,11(2):423-435
This paper analyses environmental and socio-economic barriers for plantation activities on local and regional level and investigates
the potential for carbon finance to stimulate the increased rates of forest plantation on wasteland, i.e., degraded lands,
in southern India. Building on multidisciplinary field work and results from the model GCOMAP, the aim is to (1) identify
and characterize the barriers to plantation activities in four agro-ecological zones in the state of Karnataka and (2) investigate
what would be required to overcome these barriers and enhance the plantation rate and productivity. The results show that
a rehabilitation of the wasteland based on plantation activities is not only possible but also anticipated by the local population
and would lead to positive environmental and socio-economic effects at a local level. However, in many cases, the establishment
of plantation activities is hindered by a lack of financial resources, low land productivity and water scarcity. Based on
the model used and the results from the field work, it can be concluded that certified emission reductions such as carbon
credits or other compensatory systems may help to overcome the financial barrier; however, the price needs to be significantly
increased if these measures are to have any large-scale impact. 相似文献
2.
Opel O Palm WU Steffen D Ruck WK 《Environmental pollution (Barking, Essex : 1987)》2011,159(4):924-931
Comparability of sediment analyses for semivolatile organic substances is still low. Neither screening of the sediments nor organic-carbon based normalization is sufficient to obtain comparable results. We are showing the interdependency of grain-size effects with inside-sediment organic-matter distribution for PAH, PCB and organochlorine compounds. Surface sediment samples collected by Van-Veen grab were sieved and analyzed for 16 PAH, 6 PCB and 18 organochlorine pesticides (OCP) as well as organic-matter content. Since bulk concentrations are influenced by grain-size effects themselves, we used a novel normalization method based on the sum of concentrations in the separate grain-size fractions of the sediments. By calculating relative normalized concentrations, it was possible to clearly show underlying mechanisms throughout a heterogeneous set of samples. Furthermore, we were able to show that, for comparability, screening at <125 μm is best suited and can be further improved by additional organic-carbon normalization. 相似文献
3.
Friedrich U von Oheimb G Dziedek C Kriebitzsch WU Selbmann K Härdtle W 《Environmental pollution (Barking, Essex : 1987)》2011,159(12):3553-3559
We analysed growth strategies (biomass allocation, nutrient sequestration and allocation) of heather (Calluna vulgaris) and purple moor-grass (Molinia caerulea) seedlings in monocultures and mixtures in relation to N, P, and N + P fertilisation in a greenhouse experiment in order to simulate a heath’s pioneer phase under high airborne nitrogen (N) loads. N fertilisation increased the total biomass of both species in monocultures. In mixtures, M. caerulea sequestered about 65% of the N applied, while C. vulgaris suffered from N shortage (halving of the total biomass). Thus, in mixtures only M. caerulea will benefit from airborne N loads, and competition will become increasingly asymmetric with increasing N availability. Our results demonstrate that the heath’s pioneer phase is the crucial tipping point at which the competitive vigour of M. caerulea (high belowground allocation, efficient use of belowground resources, shortened reproductive cycles) induces a shift to dominance of grasses under increased N availability. 相似文献
4.
This paper presents and discusses the method and results of account for material flows in Sweden for the year 2004. The results show that it is possible to compile material flow data from existing sources in the Swedish statistical system. By using the European classification system of goods, the Combined Nomenclature, as the basic unit of the data collection, both data collection and aggregation into material flow categories were made possible. Although these data exist in the statistical system, they are not easily available for the scientific community. This is due to several reasons, such as the aggregation of data in the system of statistics not corresponding to the material flow account structure and the fact that data on import and export of materials are organised differently than data for domestic extraction. Almost 50% of the material flows in Sweden are flows of minerals, mainly construction minerals followed by iron ores. Most of the extracted iron ores are exported. In comparison with other European countries this generates a unique situation with Sweden as the only net exporter of iron ores. The flow of biomass in terms of wood is also considerable (26% of the Swedish material flows in 2004). The domestic material consumption (inflow) per capita in 2004 was 8 tonnes minerals, 6 tonnes biomass and almost 3 tonnes of fossil fuels. Of the material flows of fossil fuels petroleum and natural gas dominates with 90%. 相似文献
5.
Jenny Palm 《Local Environment》2006,11(4):445-457
Case studies of two Swedish municipalities indicate that the general energy area was divided into three independent policy areas: one dealing with supply, one with conservation and one with environmental questions related to the Agenda 21 vision of an ecologically sustainable energy system. However, the dominant energy policy area in the municipalities was supply policy. This article discusses why supply policy is dominant and the consequences of this for energy system development. Analysis of this pattern reveals that powerful actors, such as local energy companies, were able to mobilize support for supply policies, not least because they owned the energy plants and distribution networks. These actors were also represented in many different decision arenas; in contrast, actors representing the other energy policy areas often lacked power and resources, and were represented in only a few decision arenas. 相似文献
6.
Restoration of rivers used for timber floating: effects on riparian plant diversity. 总被引:1,自引:0,他引:1
James M Helfield Samantha J Capon Christer Nilsson Roland Jansson Daniel Palm 《Ecological applications》2007,17(3):840-851
Fluvial processes such as flooding and sediment deposition play a crucial role in structuring riparian plant communities. In rivers throughout the world, these processes have been altered by channelization and other anthropogenic stresses. Yet despite increasing awareness of the need to restore natural flow regimes for the preservation of riparian biodiversity, few studies have examined the effects of river restoration on riparian ecosystems. In this study, we examined the effects of restoration in the Ume River system, northern Sweden, where tributaries were channelized to facilitate timber floating in the 19th and early 20th centuries. Restoration at these sites involved the use of heavy machinery to replace instream boulders and remove floatway structures that had previously lined stream banks and cut off secondary channels. We compared riparian plant communities along channelized stream reaches with those along reaches that had been restored 3-10 years prior to observation. Species richness and evenness were significantly increased at restored sites, as were floodplain inundation frequencies. These findings demonstrate how river restoration and associated changes in fluvial disturbance regimes can enhance riparian biodiversity. Given that riparian ecosystems tend to support a disproportionate share of regional species pools, these findings have potentially broad implications for biodiversity conservation at regional or landscape scales. 相似文献
7.
The pattern for distribution of genetic variation within and between populations is referred to as the genetic population structure of the species. To avoid depletion of genetic resources sustainable management should be based on knowledge of this structure. We discuss key aspects of genetic population structure in the context of identifying biological units for fisheries management, suggesting three basic types of structuring: distinct populations; continuous change; and no differentiation. The type of structure determines how units for genetically sustainable management are to be identified. We also review what is currently known regarding the genetic population structure of fishes exploited in the Swedish part of the Baltic Sea, and conclude that sufficient genetic information is lacking for most of the species. This is a serious problem, particularly considering that populations of several commercially exploited fishes are declining and some exhibit recruitment problems. For six species, Atlantic herring, Atlantic salmon, brown trout, European eel, turbot, and pike, sufficient genetic data are available to provide at least basic information on genetic structure and genetic units for biologically sustainable use. Current management practices do not sufficiently consider these data. 相似文献
8.
Helena Larsdotter Mellström Magne Friberg Anna-Karin Borg-Karlson Rushana Murtazina Mikael Palm Christer Wiklund 《Behavioral ecology and sociobiology》2010,64(9):1377-1383
Insects with two or more generations per year will generally experience different selection regimes depending on the season,
and accordingly show seasonal polyphenisms. In butterflies, seasonal polyphenism has been shown with respect to morphology,
life history characteristics and behaviour. In temperate bivoltine species, the directly developing generation is more time-constrained
than the diapause generation, and this may affect various life history traits such as mating propensity (time from eclosion
to mating). Here, we test whether mating propensity differs between generations in Pieris napi, along with several physiological parameters, i.e. male sex pheromone synthesis, and female ovigeny index and fecundity.
As predicted, individuals of the directly developing generation—who have shorter time for pupal development—are more immature
at eclosion; males take longer to synthesise the male sex pheromone after eclosion and take longer to mate than diapause generation
males. Females show the same physiological pattern; the directly developing females lay fewer eggs than diapausing females
during the first days of their life. Nevertheless, the directly developing females mate faster after eclosion than diapausing
females, indicating substantial adult time stress in this generation and possibly an adaptive value of shortening the pre-reproductive
period. Our study highlights how time stress can be predictably different between generations, affecting both life history
and behaviour. By analysing several life history traits simultaneously, we adopt a multi-trait approach to examining how adaptations
and developmental constraints likely interplay to shape these seasonal polyphenisms. 相似文献
9.
Rosenfeld J Hogan D Palm D Lundquist H Nilsson C Beechie TJ 《Environmental management》2011,47(1):28-39
Sediment size and supply exert a dominant control on channel structure. We review the role of sediment supply in channel structure,
and how regional differences in sediment supply and landuse affect stream restoration priorities. We show how stream restoration
goals are best understood within a common fluvial geomorphology framework defined by sediment supply, storage, and transport.
Landuse impacts in geologically young landscapes with high sediment yields (e.g., coastal British Columbia) typically result
in loss of instream wood and accelerated sediment inputs from bank erosion, logging roads, hillslopes and gullies. In contrast,
northern Sweden and Finland are landscapes with naturally low sediment yields caused by low relief, resistant bedrock, and
abundant mainstem lakes that act as sediment traps. Landuse impacts involved extensive channel narrowing, removal of obstructions,
and bank armouring with boulders to facilitate timber floating, thereby reducing sediment supply from bank erosion while increasing
export through higher channel velocities. These contrasting landuse impacts have pushed stream channels in opposite directions
(aggradation versus degradation) within a phase-space defined by sediment transport and supply. Restoration in coastal British
Columbia has focused on reducing sediment supply (through bank and hillslope stabilization) and restoring wood inputs. In
contrast, restoration in northern Fennoscandia (Sweden and Finland) has focused on channel widening and removal of bank-armouring
boulders to increase sediment supply and retention. These contrasting restoration priorities illustrate the consequences of
divergent regional landuse impacts on sediment supply, and the utility of planning restoration activities within a mechanistic
sediment supply-transport framework. 相似文献
10.