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1.
Environ Manage ; 2024 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-38563987

RESUMEN

Peatlands play a key role in the circulation of the main greenhouse gases (GHG) - methane (CH4), carbon dioxide (CO2), and nitrous oxide (N2O). Therefore, detecting the spatial pattern of GHG sinks and sources in peatlands is pivotal for guiding effective climate change mitigation in the land use sector. While geospatial environmental data, which provide detailed spatial information on ecosystems and land use, offer valuable insights into GHG sinks and sources, the potential of directly using remote sensing data from satellites remains largely unexplored. We predicted the spatial distribution of three major GHGs (CH4, CO2, and N2O) sinks and sources across Finland. Utilizing 143 field measurements, we compared the predictive capacity of three different data sets with MaxEnt machine-learning modeling: (1) geospatial environmental data including climate, topography and habitat variables, (2) remote sensing data (Sentinel-1 and Sentinel-2), and (3) a combination of both. The combined dataset yielded the highest accuracy with an average test area under the receiver operating characteristic curve (AUC) of 0.845 and AUC stability of 0.928. A slightly lower accuracy was achieved using only geospatial environmental data (test AUC 0.810, stability AUC 0.924). In contrast, using only remote sensing data resulted in reduced predictive accuracy (test AUC 0.763, stability AUC 0.927). Our results suggest that (1) reliable estimates of GHG sinks and sources cannot be produced with remote sensing data only and (2) integrating multiple data sources is recommended to achieve accurate and realistic predictions of GHG spatial patterns.

2.
Oecologia ; 204(3): 689-704, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38478083

RESUMEN

Subarctic ecosystems are subjected to increasing nitrogen (N) enrichment and disturbances that induce particularly strong effects on plant communities when occurring in combination. There is little experimental evidence on the longevity of these effects. We applied N-fertilization (40 kg urea-N ha-1 year-1 for 4 years) and disturbance (removal of vegetation and organic soil layer on one occasion) in two plant communities in a subarctic forest-tundra ecotone in northern Finland. Within the first four years, N-fertilization and disturbance increased the share of deciduous dwarf shrubs and graminoids at the expense of evergreen dwarf shrubs. Individual treatments intensified the other's effect resulting in the strongest increase in graminoids under combined N-fertilization and disturbance. The re-analysis of the plant communities 15 years after cessation of N-fertilization showed an even higher share of graminoids. 18 years after disturbance, the total vascular plant abundance was still substantially lower and the share of graminoids higher. At the same point, the plant community composition was the same under disturbance as under combined N-fertilization and disturbance, indicating that multiple perturbations no longer reinforced the other's effect. Yet, complex interactions between N-fertilization and disturbance were still detected in the soil. We found higher organic N under disturbance and lower microbial N under combined N-fertilization and disturbance, which suggests a lower bioavailability of N sources for soil microorganisms. Our findings support that the effects of enhanced nutrients and disturbance on subarctic vegetation persist over decadal timescales. However, they also highlight the complexity of plant-soil interactions that drive subarctic ecosystem responses to multiple perturbations across varying timescales.


Asunto(s)
Ecosistema , Tundra , Plantas , Suelo , Fertilización
3.
Sci Rep ; 14(1): 2489, 2024 01 30.
Artículo en Inglés | MEDLINE | ID: mdl-38291097

RESUMEN

Peatlands provide a variety of ecosystem services besides being important ecosystems for biodiversity. Sustainable peatland management requires that its impacts are identified, and all management is allocated in a cost-efficient manner. In this study, we assessed how peatland management influences the habitat suitability of red-listed plant species and the financial performance of management measured as net present value (NPV). The study was done in three landscapes in Finland. We considered four peatland management scenarios i.e., no management activity (NOMANAGE), hydrological restoration (REST), wood harvesting for bioenergy (BIOENERGY), and timber production (TIMBER). The NPVs of different management scenarios were compared to the habitat suitability of red-listed peatland plant species. A cost-impact analysis was used, with TIMBER as a baseline scenario, to find out which alternative scenario would be the most cost-efficient in contributing to habitat suitability. Our study shows that potential habitat areas were significantly different between the scenarios. REST provided the largest potential habitat areas, followed by BIOENERGY, NOMANAGE, and TIMBER. TIMBER provided the best financial performance when low interest rates were used. REST and BIOENERGY were more cost-efficient in enhancing potential habitat areas than NOMANAGE. REST would improve suitable habitats and provide financial benefits when a higher interest rate was used. In conclusion, even a win-win condition could be achieved in some cases (33%), in which higher NPV was achieved simultaneously with improved potential habitat areas. The study provides information for alleviating the economic barriers of restoration and targeting land use and management options cost-efficiently.


Asunto(s)
Biodiversidad , Ecosistema , Finlandia , Madera , Costos y Análisis de Costo , Conservación de los Recursos Naturales
4.
Sci Rep ; 13(1): 6283, 2023 04 18.
Artículo en Inglés | MEDLINE | ID: mdl-37072453

RESUMEN

The Nordic Bioeconomy Pathways (NBPs), conceptualized subsets of Shared Socioeconomic Pathways varying from environmentally friendly to open-market competition scenarios, can lead to plausible stressors in future for using bioresources. This study analysed the impacts of NBPs on hydrology and water quality based on two different land system management attributes: management strategy and a combination of reduced stand management and biomass removal at a catchment-scale projection. To understand the potential impacts of NBPs, the Simojoki catchment in northern Finland was chosen, as the catchment mainly covered peatland forestry. The analysis integrated a stakeholder-driven questionnaire, the Finnish Forest dynamics model, and Soil and Water Assessment Tool to build NBP scenarios, including Greenhouse gas emission pathways, for multiple management attributes to simulate flows, nutrients, and suspended solids (SS). For the catchment management strategy, an annual decrease in nutrients was observed for sustainability and business-as-usual scenarios. Reduced stand management and biomass removal also led to decreased export of nutrients and SS for the same scenarios, whereas, in other NBPs, the export of nutrients and SS increased with decreased evapotranspiration. Although the study was investigated at a local scale, based on the current political and socioeconomic situation, the approach used in this study can be outscaled to assess the use of forest and other bioresources in similar catchments.


Asunto(s)
Modelos Teóricos , Calidad del Agua , Bosques , Suelo , Agricultura Forestal
5.
Sci Total Environ ; 882: 163583, 2023 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-37086986

RESUMEN

After drainage for forestry and agriculture, peat extraction is one of the most important causes of peatland degradation. When peat extraction is ceased, multiple after-use options exist, including abandonment, restoration, and replacement (e.g., forestry and agricultural use). However, there is a lack of a global synthesis of after-use research. Through a systematic review of 356 peer-reviewed scientific articles, we address this research gap and examine (1) what after-use options have been studied, (2) what the studied and recognized impacts of the after-use options are, and (3) what one can learn in terms of best practices and research gaps. The research has concentrated on the impacts of restoration (N = 162), abandonment (N = 72), and replacement (N = 94), the latter of which consists of afforestation (N = 46), cultivation (N = 34) and creation of water bodies (N = 14). The studies on abandonment, restoration, and creation of water bodies have focused mostly on analyzing vegetation and greenhouse gas (GHG) fluxes, while the studies assessing afforestation and cultivation sites mostly evaluate the provisioning ecosystem services. The studies show that active restoration measures speed-up vegetation recolonization on bare peat areas, reduce GHG emissions and decrease negative impacts on water systems. The most notable research gap is the lack of studies comparing the environmental and social impacts of the after-use options. Additionally, there is a lack of studies focusing on social impacts and downstream hydrology, as well as long-term monitoring of GHG fluxes. Based on the reviewed studies, a comparison of the impacts of the after-use options is not straightforward. We emphasize a need for comparative empirical research in the extracted sites with a broad socio-ecological and geographical context.


Asunto(s)
Gases de Efecto Invernadero , Suelo , Ecosistema , Cambio Social , Hidrología , Biodiversidad
6.
Mol Ecol ; 32(2): 504-517, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36318600

RESUMEN

Anthropogenic changes to land use drive concomitant changes in biodiversity, including that of the soil microbiota. However, it is not clear how increasing intensity of human disturbance is reflected in the soil microbial communities. To address this issue, we used amplicon sequencing to quantify the microbiota (bacteria and fungi) in the soil of forests (n = 312) experiencing four different land uses, national parks (set aside for nature conservation), managed (for forestry purposes), suburban (on the border of an urban area) and urban (fully within a town or city), which broadly represent a gradient of anthropogenic disturbance. Alpha diversity of bacteria and fungi increased with increasing levels of anthropogenic disturbance, and was thus highest in urban forest soils and lowest in the national parks. The forest soil microbial communities were structured according to the level of anthropogenic disturbance, with a clear urban signature evident in both bacteria and fungi. Despite notable differences in community composition, there was little change in the predicted functional traits of urban bacteria. By contrast, urban soils exhibited a marked loss of ectomycorrhizal fungi. Soil pH was positively correlated with the level of disturbance, and thus was the strongest predictor of variation in alpha and beta diversity of forest soil communities, indicating a role of soil alkalinity in structuring urban soil microbial communities. Hence, our study shows how the properties of urban forest soils promote an increase in microbial diversity and a change in forest soil microbiota composition.


Asunto(s)
Micorrizas , Suelo , Humanos , Suelo/química , Bosques , Hongos/genética , Bacterias/genética , Biodiversidad , Microbiología del Suelo
7.
J Environ Manage ; 316: 115174, 2022 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-35658267

RESUMEN

Land-use conflicts can be costly and time-consuming and cause social burden to all parties. In this study, we developed an approach for mapping synergy and conflict potential between land uses and tested it on nature protection, nature-based tourism, forestry and mining. First, we calculated the ecological and socio-cultural values for the study area, and further the economic values related to forestry and mining. Second, we conducted an integrated spatial assessment of these values and used it jointly with a variant of a value compatibility analysis to locate areas with possible synergistic and conflicting land uses. This study was carried out in Finnish Lapland where land use conflicts have occurred due to the need to develop forestry and mining in areas that are also important for nature-based tourism. The method operated well as it identified sites with ongoing land-use disputes. Synergy potential between biodiversity and socio-cultural values was identified in protected areas and other sites of natural beauty, and conflict potential concerning forestry near tourist resorts and concerning mining at proposed mining project sites. The developed framework can assist in locating sites that may need proactive measurements to avoid conflicts, and sites that would benefit from multi-purpose management thereby supporting sustainable and adaptive land-use planning.


Asunto(s)
Biodiversidad , Agricultura Forestal , Conservación de los Recursos Naturales , Ecosistema , Finlandia , Minería
8.
Ambio ; 49(11): 1722-1735, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32918722

RESUMEN

Nordic water bodies face multiple stressors due to human activities, generating diffuse loading and climate change. The 'green shift' towards a bio-based economy poses new demands and increased pressure on the environment. Bioeconomy-related pressures consist primarily of more intensive land management to maximise production of biomass. These activities can add considerable nutrient and sediment loads to receiving waters, posing a threat to ecosystem services and good ecological status of surface waters. The potential threats of climate change and the 'green shift' highlight the need for improved understanding of catchment-scale water and element fluxes. Here, we assess possible bioeconomy-induced pressures on Nordic catchments and associated impacts on water quality. We suggest measures to protect water quality under the 'green shift' and propose 'road maps' towards sustainable catchment management. We also identify knowledge gaps and highlight the importance of long-term monitoring data and good models to evaluate changes in water quality, improve understanding of bioeconomy-related impacts, support mitigation measures and maintain ecosystem services.


Asunto(s)
Ecosistema , Calidad del Agua , Cambio Climático , Predicción , Humanos , Modelos Teóricos
9.
Int J Biometeorol ; 64(10): 1783-1793, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32632472

RESUMEN

Plant phenological dataset collected at 42 sites across the mainland of Finland and covering the years 1997-2017 is presented and analysed for temporal trends. The dataset of n = 16,257 observations represents eleven plant species and fifteen phenological stages and results in forty different variables, i.e. phenophases. Trend analysis was carried out for n = 808 phenological time-series that contained at least 10 observations over the 21-year study period. A clear signal of advancing spring and early-summer phenology was detected, 3.4 days decade-1, demonstrated by a high proportion of negative trends for phenophases occurring in April through June. Latitudinal correlation indicated stronger signal of spring and early-summer phenology towards the northern part of the study region. The autumn signal was less consistent and showed larger within-site variations than those observed in other seasons. More than 60% of the dates based on single tree/monitoring square were exactly the same as the averages from multiple trees/monitoring squares within the site. In particular, the reliability of data on autumn phenology was increased by multiple observations per site. The network is no longer active.


Asunto(s)
Clima , Árboles , Cambio Climático , Finlandia , Reproducibilidad de los Resultados , Estaciones del Año , Temperatura
10.
Data Brief ; 31: 105724, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32478157

RESUMEN

We present the first dataset that can be used to associate peoples' opinions with comprehensive biodiversity and cultural heritage values. The socio-ecological dataset includes 1) place-based information on peoples' recreational activities, values expressed as pleasant and unpleasant sites, and negative preferences concerning land use in terms of tourism, nature protection and forestry, and 2) compiled information on scored biodiversity values and protection level of sites. The data are organized in 1ha grid cells. The data were compiled from a rural nature-based tourism area in two municipalities northern Finland. Peoples' opinions were assessed using a public participation geographic information system (PPGIS) and the data were merged with spatial biodiversity data from the same area. The data are directly related to the article Tolvanen et al. [1]. Biodiversity data, also utilized in Tolvanen et al. 2020, were compiled from various sources and scoring was done in Kangas et al. [2]. References to individual respondents and spatial locations of markings were removed. The data are useful in evaluating the relationship between people's values and biodiversity.

11.
J Environ Manage ; 233: 832-844, 2019 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-30600123

RESUMEN

The development of mining and other resource-based industries are among key drivers of economic development in the Arctic. The fragile environment and the presence of nature-based livelihoods and indigenous communities pose challenges for mining development. Mining operations should be optimized so that the profitability is maintained in changing market conditions and to meet increasing societal and environmental demands. In this study we present the current understanding on the interplay between mining and the surrounding socio-ecological systems in the Arctic region. The existing academic literature on the Arctic region was reviewed, covering 127 peer-reviewed publications since 2000. We investigated the mining activities from four perspectives examining: 1) environmental, 2) economic, 3) social and 4) legal dimensions, covering three life-cycle stages: 1) pre-mining, 2) mining, and 3) post-mining. The publications on the environmental and economic aspects focused principally on the impacts of mining, whereas social and legal publications discussed the interaction between people and their rights and ways of controlling their environment. Besides the need for more balanced research between different life-cycle stages we uncovered five research gaps concerning the knowledge base needed to increase the sustainability of Arctic mining: 1) impacts and adaptation to climate change, 2) monitoring the sustainability of mining using standardized indicators, 3) holistic economic assessment of mining, 4) social sustainability and conflict management, and 5) mechanisms that mitigate or compensate for the adverse effects of mining on biodiversity.


Asunto(s)
Ambiente , Minería , Regiones Árticas , Ecología , Factores Socioeconómicos
12.
Int J Biometeorol ; 62(6): 1109-1113, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29455297

RESUMEN

The Pan European Phenology (PEP) project is a European infrastructure to promote and facilitate phenological research, education, and environmental monitoring. The main objective is to maintain and develop a Pan European Phenological database (PEP725) with an open, unrestricted data access for science and education. PEP725 is the successor of the database developed through the COST action 725 "Establishing a European phenological data platform for climatological applications" working as a single access point for European-wide plant phenological data. So far, 32 European meteorological services and project partners from across Europe have joined and supplied data collected by volunteers from 1868 to the present for the PEP725 database. Most of the partners actively provide data on a regular basis. The database presently holds almost 12 million records, about 46 growing stages and 265 plant species (including cultivars), and can be accessed via http://www.pep725.eu/ . Users of the PEP725 database have studied a diversity of topics ranging from climate change impact, plant physiological question, phenological modeling, and remote sensing of vegetation to ecosystem productivity.


Asunto(s)
Bases de Datos Factuales , Estaciones del Año , Europa (Continente)
13.
J Environ Manage ; 210: 71-86, 2018 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-29331627

RESUMEN

Common to multi-objective forest planning situations is that they all require comparisons, searches and evaluation among decision alternatives. Through these actions, the decision maker can learn from the information presented and thus make well-justified decisions. Interactive data visualization is an evolving approach that supports learning and decision making in multidimensional decision problems and planning processes. Data visualization contributes the formation of mental image data and this process is further boosted by allowing interaction with the data. In this study, we introduce a multi-objective forest planning decision problem framework and the corresponding characteristics of data. We utilize the framework with example planning data to illustrate and evaluate the potential of 14 interactive data visualization techniques to support multi-objective forest planning decisions. Furthermore, broader utilization possibilities of these techniques to incorporate the provisioning of ecosystem services into forest management and planning are discussed.


Asunto(s)
Técnicas de Apoyo para la Decisión , Agricultura Forestal , Toma de Decisiones , Ecosistema , Bosques
14.
Sci Total Environ ; 586: 858-869, 2017 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-28215796

RESUMEN

Restoration impact of forestry-drained peatlands on runoff water quality and dissolved organic carbon (DOC) and nutrient export was studied. Eight catchments were included: three mesotrophic (one undrained control, two treatments), two ombrotrophic (one drained control, one treatment) and three oligotrophic catchments (one undrained control, two treatments). Three calibration years and four post-restoration years were included in the data from seven catchments, for which runoff was recorded. For one mesotrophic treatment catchment only one year of pre-restoration and two years of post-restoration water quality data is reported. Restoration was done by filling in and damming the ditches. Water samples were collected monthly-biweekly during the snow-free period; runoff was recorded continuously during the same period. Water quality was estimated for winter using ratios derived from external data. Runoff for non-recorded periods were estimated using the FEMMA model. A high impact on DOC, nitrogen (N) and phosphorus (P) was observed in the mesotrophic catchments, and mostly no significant impact in the nutrient-poor catchments. The DOC load from one catchment exceeded 1000kg (restored-ha)-1 in the first year; increase of DOC concentration from 50 to 250mgl-1 was observed in the other mesotrophic treatment catchment. Impact on total nitrogen export of over 30kg (restored-ha)-1 was observed in one fertile catchment during the first year. An impact of over 5kg (restored-ha)-1 on ammonium export was observed in one year in the mesotrophic catchment. Impact on P export from the mesotrophic catchment was nearly 5kg P (restored-ha)-1 in the first year. The results imply that restoration of nutrient-rich forestry-drained peatlands poses significant risk for at least short term elevated loads degrading the water quality in receiving water bodies. Restoration of nutrient-poor peatlands poses a minor risk in comparison. Research is needed regarding the factors behind these risks and how to mitigate them.

16.
J Environ Manage ; 169: 58-66, 2016 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-26720330

RESUMEN

Tourist numbers in northern Fennoscandia outweigh those in other northern boreal - arctic regions, which creates a specific need to evaluate the impacts of tourism. This review 1) identifies patterns and trends in the vegetation and wildlife of northern Fennoscandian terrestrial ecosystems as a consequence of tourism and recreation, 2) discusses the implications of findings in terms of the intensity, area and magnitude of impacts, changing climate and management needs under increasing tourist pressure, and 3) identifies research gaps. The reviewed studies show negative environmental and biodiversity impacts that are most pronounced near tourist resorts. The most sensitive plants, birds and mammals decline or disappear from the disturbed sites, and the species composition shifts from 'wild' species to cultural and human associated species. There is little research on the spread of alien species, but the few examples show that alien species can be promoted by tourism activities. Impacts of the use of motorized vehicles have not been widely studied either, despite the extensive track network which can cause disturbance to wildlife. The integrated impacts of tourism and climate change on the vegetation and wildlife was not addressed directly in any of the reviewed studies. In addition, little research has been done on carrying out restoration at tourist areas. Scientific research on these topics is needed to prevent, minimize or restore the most negative ecological impacts of tourism and recreation.


Asunto(s)
Biodiversidad , Conservación de los Recursos Naturales , Recreación , Animales , Regiones Árticas , Cambio Climático , Ecosistema , Europa (Continente) , Humanos , Especies Introducidas
17.
Int J Biometeorol ; 60(8): 1227-36, 2016 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26686678

RESUMEN

Trends in the timing of spring and autumn phenophases of Betula pubescens were investigated in the southern, middle, and northern boreal zones in Finland. The field observations were carried out at 21 sites in the Finnish National Phenological Network in 1997-2013. The effective temperature sum of the thermal growth period, i.e. the sum of the positive differences between diurnal mean temperatures and 5 °C (ETS1), increased annually on average by 6-7 degree day units. Timing of bud burst remained constant in the southern and middle boreal zones but advanced annually by 0.5 day in the northern boreal zone. The effective temperature sum at bud burst (ETS2) showed no trend in the southern and middle boreal zones, whereas ETS2 increased on average from 20-30 to 50 degree day units in the northern boreal zone, almost to the same level as in the other zones. Increase in ETS2 indicates that the trees did not start their growth in very early spring despite warmer spring temperatures. The timing of leaf colouring and leaf fall remained almost constant in the southern boreal zones, whereas these advanced annually by 0.3 and 0.6 day in the middle boreal zone and by 0.6 and 0.4 day in the northern boreal zone, respectively. The duration of the growth period remained constant in all boreal zones. The results indicate high buffering capacity of B. pubescens against temperature changes. The study also shows the importance of the duration of phenological studies: some trends in spring phenophases had levelled out, while new trends in autumn phases had emerged after earlier studies in the same network for a shorter observation period.


Asunto(s)
Betula/crecimiento & desarrollo , Temperatura , Clima , Finlandia , Hojas de la Planta/crecimiento & desarrollo , Estaciones del Año
18.
Ecol Evol ; 6(19): 6880-6891, 2016 10.
Artículo en Inglés | MEDLINE | ID: mdl-28725366

RESUMEN

Young coastal fens are rare ecosystems in the first stages of peatland succession. Their drainage compromises their successional development toward future carbon (C) reservoirs. We present the first study on the success of hydrological restoration of young fens. We carried out vegetation surveys at six young fens that represent undrained, drained, and restored management categories in the Finnish land uplift coast before and after restoration. We measured plant level carbon dioxide (CO2) assimilation and chlorophyll fluorescence (Fv/Fm) from 17 most common plant species present at the sites. Within 5 years of restoration, the vegetation composition of restored sites had started to move toward the undrained baseline. The cover of sedges increased the most in response to restoration, while the cover of deciduous shrubs decreased the most. The rapid response indicates high resilience and low resistance of young fen ecosystems toward changes in hydrology. Forbs had higher photosynthetic and respiration rates than sedges, deciduous shrubs, and grasses, whereas rates were lowest for evergreen shrubs and mosses. The impact of management category on CO2 assimilation was an indirect consequence that occurred through changes in plant species composition: Increase in sedge cover following restoration also increased the potential photosynthetic capacity of the ecosystem. Synthesis and applications. Restoration of forestry drained young fens is a promising method for safeguarding them and bringing back their function as C reservoirs. However, their low resistance to water table draw down introduces a risk that regeneration may be partially hindered by the heavy drainage in the surrounding landscape. Therefore, restoration success is best safeguarded by managing the whole catchments instead of carrying out small-scale projects.

19.
Environ Sci Pollut Res Int ; 23(14): 13732-44, 2016 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-26358210

RESUMEN

Reclaiming abandoned and unmaintained roads, built originally for forestry and mineral extraction, is an important part of ecological restoration, because the roads running through natural habitats cause fragmentation. The roads can be reclaimed in a passive way by blocking access to the road, but successful seedling recruitment may require additional management due to the physical constraints present at the road. We established a full factorial study to compare the effects of three road reclaiming measures, namely ripping, creation of safe sites by adding mulch and pine seed addition, on soil processes, recovery of understorey vegetation and seedling recruitment in three conservation areas in eastern Finland. We surveyed soil organic matter, frequency and cover of plant functional types, litter and mineral soil, and number of tree seedlings. The soil organic matter was, on average, 1.3-fold in the 50-cm-deep ripping treatment relative to unripped and 20-cm-deep ripping treatments. The germination and survival of deciduous seedlings and grass establishment were promoted by adding mulch. The addition of pine seeds counteracted the seed limitation and enhanced the regeneration of trees. The treatment combination consisting of ripping, adding mulch and pine seed addition enhanced the vegetation succession and tree-seedling recruitment most: the cover of grasses, herbs and ericaceous dwarf shrubs was 1.3-7.6-fold and the number of coniferous tree seedlings was 3.4-7.1-fold relative to the other treatment combinations. Differences between short-term (1-3 years) and longer-term (6 years) results indicate the need for a sufficient observation period in road reclamation studies.


Asunto(s)
Conservación de los Recursos Naturales/métodos , Industria de la Construcción , Bosques , Plantones/fisiología , Transportes , Árboles/fisiología , Finlandia , Plantones/crecimiento & desarrollo , Árboles/crecimiento & desarrollo
20.
Glob Chang Biol ; 21(10): 3696-711, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25950664

RESUMEN

Selective herbivory of palatable plant species provides a competitive advantage for unpalatable plant species, which often have slow growth rates and produce slowly decomposable litter. We hypothesized that through a shift in the vegetation community from palatable, deciduous dwarf shrubs to unpalatable, evergreen dwarf shrubs, selective herbivory may counteract the increased shrub abundance that is otherwise found in tundra ecosystems, in turn interacting with the responses of ecosystem carbon (C) stocks and CO2 balance to climatic warming. We tested this hypothesis in a 19-year field experiment with factorial treatments of warming and simulated herbivory on the dominant deciduous dwarf shrub Vaccinium myrtillus. Warming was associated with a significantly increased vegetation abundance, with the strongest effect on deciduous dwarf shrubs, resulting in greater rates of both gross ecosystem production (GEP) and ecosystem respiration (ER) as well as increased C stocks. Simulated herbivory increased the abundance of evergreen dwarf shrubs, most importantly Empetrum nigrum ssp. hermaphroditum, which led to a recent shift in the dominant vegetation from deciduous to evergreen dwarf shrubs. Simulated herbivory caused no effect on GEP and ER or the total ecosystem C stocks, indicating that the vegetation shift counteracted the herbivore-induced C loss from the system. A larger proportion of the total ecosystem C stock was found aboveground, rather than belowground, in plots treated with simulated herbivory. We conclude that by providing a competitive advantage to unpalatable plant species with slow growth rates and long life spans, selective herbivory may promote aboveground C stocks in a warming tundra ecosystem and, through this mechanism, counteract C losses that result from plant biomass consumption.


Asunto(s)
Biodiversidad , Biomasa , Ciclo del Carbono , Calentamiento Global , Herbivoria , Magnoliopsida/fisiología , Finlandia , Tundra
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