Umeå universitets logga

umu.sePublikationer
Ändra sökning
Avgränsa sökresultatet
1 - 17 av 17
RefereraExporteraLänk till träfflistan
Permanent länk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Träffar per sida
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sortering
  • Standard (Relevans)
  • Författare A-Ö
  • Författare Ö-A
  • Titel A-Ö
  • Titel Ö-A
  • Publikationstyp A-Ö
  • Publikationstyp Ö-A
  • Äldst först
  • Nyast först
  • Skapad (Äldst först)
  • Skapad (Nyast först)
  • Senast uppdaterad (Äldst först)
  • Senast uppdaterad (Nyast först)
  • Disputationsdatum (tidigaste först)
  • Disputationsdatum (senaste först)
  • Standard (Relevans)
  • Författare A-Ö
  • Författare Ö-A
  • Titel A-Ö
  • Titel Ö-A
  • Publikationstyp A-Ö
  • Publikationstyp Ö-A
  • Äldst först
  • Nyast först
  • Skapad (Äldst först)
  • Skapad (Nyast först)
  • Senast uppdaterad (Äldst först)
  • Senast uppdaterad (Nyast först)
  • Disputationsdatum (tidigaste först)
  • Disputationsdatum (senaste först)
Markera
Maxantalet träffar du kan exportera från sökgränssnittet är 250. Vid större uttag använd dig av utsökningar.
  • 1. Aguiar, Francisca C.
    et al.
    Segurado, Pedro
    Martins, Maria Joao
    Bejarano, Maria Dolores
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Nilsson, Christer
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Portela, Maria Manuela
    Merritt, David M.
    The abundance and distribution of guilds of riparian woody plants change in response to land use and flow regulation2018Ingår i: Journal of Applied Ecology, ISSN 0021-8901, E-ISSN 1365-2664, Vol. 55, nr 5, s. 2227-2240Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    1. Many riparian ecosystems in Mediterranean Europe are affected by land use and flow alteration by dams. We focused on understanding how these stressors and their components affect riparian forests in the region. We asked the following questions: (1) Are there well‐defined, responsive riparian guilds? (2) Do dam‐induced streamflows determine abundance and distribution of riparian guilds? (3) What are the main drivers governing composition and cover of riparian guilds in regulated rivers?

    2. We inventoried the cover of riparian woody species in free‐flowing rivers and downstream of dams. We performed a cluster analysis and ordination to derive riparian guilds, using abundance data from 66 riparian woody species and 26 functional plant traits. We used a reduced set of principal components for the environment, land use and hydrology, and general linear modelling to explore the effect of these factors (separately and combined) on riparian guilds.

    3. We found that: (1) four dominant guilds are responsive to disturbance in southwestern European streams, namely the obligate riparian, water‐stress tolerant, deciduous competitive and Mediterranean evergreen guilds; (2) a set of land use and hydrological variables differentially affect the diverse co‐occurring riparian guilds; (3) frequency and duration of high flow pulses and the low‐flow conditions were major drivers of change in landscapes dominated by intensive agriculture and forestry; (4) storage reservoirs reduced the cover of obligate riparian and Mediterranean evergreen guilds, and increased the abundance of water‐stress tolerant and deciduous competitive guilds, while run‐of‐river dams, having limited water storage, reduced both obligate and deciduous competitive guilds.

    4. Synthesis and applications. Future research in southwestern Europe should address the resilience of riparian guilds and the effects of interacting landscape factors and stressors on guild distribution. Streamflow regulations downstream of reservoirs should focus on specific flow components, namely the magnitude of flows, and frequency and duration of extreme flow events. For successful mitigation of the dam‐induced effects on riparian vegetation, river management plans must incorporate the environmental and land use site‐specific contexts.

  • 2.
    Alimpić, Filip
    et al.
    Singidunum University - Environment and Sustainable Development, Belgrade, Serbia.
    Milovanović, Jelena
    Singidunum University - Environment and Sustainable Development, Belgrade, Serbia.
    Pielech, Remigiusz
    Department of Forest Biodiversity, Faculty of Forestry, University of Agriculture in Kraków, Kraków, Poland.
    Hinkov, Georgi
    Forest Research Institute at the Bulgarian Academy of Sciences, Sofia, Bulgaria.
    Jansson, Roland
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Dufour, Simon
    Université Rennes 2/UMR LETG, Rennes, France.
    Beza, Marcin
    The Kostrzyca Forest Gene Bank, Miłków, Poland.
    Bilir, Nebi
    Isparta University of Applied Sciences, Isparta, Turkey.
    del Blanco, Luis Santos
    CSIC-INIA-CIFOR, Madrid, Spain.
    Božič, Gregor
    Slovenian Forestry Institute, Ljubljana, Slovenia.
    Bruno, Daniel
    Pyrenean Institute of Ecology (Spanish National Research Council; IPE-CSIC), Zaragoza, Spain.
    Chiarabaglio, Pier Mario
    CREA - Research Centre for Forestry and Wood, Casale Monferrato AL, Italy.
    Doncheva, Neli
    WWF Bulgaria, Sofia, Bulgaria.
    Gültekin, Yaşar Selman
    Forest Economics Department, Düzce University, Faculty of Forest, Düzce, Turkey.
    Ivanković, Mladen
    Croatian Forest Research Institute, Jastrebarsko, Croatia.
    Kelly-Quinn, Mary
    School of Biology and Environmental Science, University College Dublin, Dublin, Ireland.
    La Porta, Nicola
    Edmund Mach Foundation, Trento, Italy.
    Nonić, Marina
    University of Belgrade - Faculty of Forestry, Belgrade, Serbia.
    Notivol, Eduardo
    CITA (Agricultural Research Centre), Aragon, Spain.
    Papastergiadou, Eva
    School of Natural Sciences - University of Patras, Rio, Greece.
    Šijačić-Nikolić, Mirjana
    University of Belgrade - Faculty of Forestry, Belgrade, Serbia.
    Vietto, Lorenzo
    CREA - Research Centre for Forestry and Wood, Casale Monferrato AL, Italy.
    Villar, Marc
    INRAE-ONF-BioForA, Orléans, France.
    Zhelev, Petar
    University of Forestry, Sofia, Bulgaria.
    Rodríguez-González, Patricia María
    Forest Research Centre - School of Agriculture - University of Lisbon, Lisbon, Portugal.
    The status and role of genetic diversity of trees for the conservation and management of riparian ecosystems: A European experts' perspective2022Ingår i: Journal of Applied Ecology, ISSN 0021-8901, E-ISSN 1365-2664, Vol. 59, nr 10, s. 2476-2485Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Riparian vegetation supports high biodiversity providing many services and is, therefore, an important landscape element. Riparian ecosystems are subject to numerous pressures leading to population decline and genetic erosion of riparian plants. This may have cascading effects at various ecosystem levels, including decreasing ecosystem services, so identifying the current status of genetic diversity of riparian tree species is vital to improve the effectiveness of restoration efforts.

    We aimed to elicit expert views on the status and importance of genetic diversity of tree species, and conservation needs across European riparian ecosystems. Sharing of such information among researchers, managers and policymakers has the potential to enhance ecological restoration and management of riparian ecosystems.

    We identified experts in riparian genetic resources conservation and management across Europe. These included stakeholders with different perspectives, ranging from researchers to practitioners. We designed a set of questionnaires where our identified experts were asked to answer questions related to the status and conservation of genetic diversity of riparian tree species in their respective countries. Specifically, we asked about societal awareness, legislative tools, good practices and conservation or restoration projects accounting for intraspecific genetic diversity and differentiation of tree species in riparian ecosystems. Questionnaire responses were analysed and discussed in light of the scientific literature to define needs and priorities related to the management and conservation of genetic diversity of riparian tree species.

    The experts recognized that a combination of in situ and ex situ measures and/or integrative conservation of riparian ecosystems is the most appropriate option for conserving the genetic diversity of riparian tree species. Simultaneous application of conservation measures at the level of priority species, identified by experts, and protection of riparian areas are required.

    Synthesis and applications. This study revealed the importance of recognizing the ecological processes that shape the genetic diversity of riparian tree species in hydrographic networks (dendritic spatial configuration, specific patterns of gene flow among riparian populations, fragmentation of river by dams) but also the need to overcome socio-economic barriers, such as lack of policy priority, deficiency in funding and weak legislation framework.

  • 3. Axelsson, E. Petter
    et al.
    Hjalten, Joakim
    LeRoy, Carri J.
    Whitham, Thomas G.
    Julkunen-Tiitto, Riitta
    Wennström, Anders
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Leaf litter from insect-resistant transgenic trees causes changes in aquatic insect community composition2011Ingår i: Journal of Applied Ecology, ISSN 0021-8901, E-ISSN 1365-2664, Vol. 48, nr 6, s. 1472-1479Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    1. Recent research has addressed how transgenic residues fromarable crops may influence adjacent waterways, aquatic consumers and important ecosystem processes such as litter breakdown rates. With future applications of transgenic plants in forestry, such concerns may apply to forest stream ecosystems. Before any large-scale release of genetically modified (GM) trees, it is therefore imperative to evaluate the effects of genetic modifications in trees on such ecosystems. 2. We conducted decomposition experiments under natural stream conditions using leaf litter from greenhouse grown GM trees (Populus tremula x Populus tremuloides) that express Bacillus thuringiensis (Bt) toxins (cry3Aa; targeting coleopteran leaf-feeding beetles) to examine the hypothesis that GM trees would affect litter decomposition rates and/or the aquatic arthropod community that colonizes and feeds on leaf litter in streams. 3. We show that two independent transformations of isogenic Populus trees to express Bt toxins caused similar changes to the composition of aquatic insects colonizing the leaf litter, ultimately manifested in a 25% and 33% increases in average insect abundance. 4. Measurements of 24 phenolic compounds as well as nitrogen (N) and carbon (C) in the litter did not significantly differ among modified and wild-type trees and were thus not sufficient to explain these differences in the insect assemblage. 5. Decomposition rates were comparable among litter treatments suggesting that the normal suite of leaf traits influencing decomposition was similar among litter treatments and that the shredding functions of the community were maintained despite the changes in insect community composition. 6. Synthesis and applications. We report that leaf litter from GM trees affected the composition of aquatic insect communities that colonized litter under natural stream conditions. This suggests that forest management using GM trees may affect adjacent waterways in unanticipated ways, which should be considered in future commercial applications of GM trees. We also argue that studies at different scales (e.g. species, communities and ecosystems) will be needed for a full understanding of the environmental effects of Bt plants.

  • 4.
    Bejarano, Maria Dolores
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Nilsson, Christer
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Aguiar, Francisca Constanca
    Riparian plant guilds become simpler and most likely fewer following flow regulation2018Ingår i: Journal of Applied Ecology, ISSN 0021-8901, E-ISSN 1365-2664, Vol. 55, nr 1, s. 365-376Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    1. River regulation affects riparian systems world-wide and conservation and restoration efforts are essential to retain biodiversity, and the functioning and services of riverine ecosystems. Effects of regulation on plant species richness have been widely addressed, but the filtering effect of regulation on guilds has received less attention.

    2. We used a functional trait approach to identify adaptive plant strategies through regulation-tolerant traits and predict shifts of riparian vegetation communities in response to regulation. We analysed variation in functional diversity across gradients of hydrological alteration in northern Sweden in relation to modified timing and infrequent major floods, along with frequent short-term inundation.

    3. Functional richness was similar in all study sites, but species richness declined with increasing intensity of regulation, and the species lost were largely functionally redundant (i.e. co-existing species that have similar contribution to an ecosystem function). Guilds of species intolerant to waterlogging were particularly unsuccessful in most regulated sites as they were affected by hydropower dams which replace major fluvial disturbances with frequent short inundation events. We predict that this guild will disappear, with likely consequences for the entire riverine ecosystem.

    4. Synthesis and applications. We conclude that functional traits tolerant to waterlogging or submergence and lack of major fluvial disturbances were key to understanding our results. We suggest that the functional trait approach can be integrated with knowledge of other ecosystem components to provide an understanding of ecosystem function that can be used to guide fluvial ecosystem management.

  • 5. Bruno, Daniel
    et al.
    Gutierrez-Canovas, Cayetano
    Sanchez-Fernandez, David
    Velasco, Josefa
    Nilsson, Christer
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Impacts of environmental filters on functional redundancy in riparian vegetation2016Ingår i: Journal of Applied Ecology, ISSN 0021-8901, E-ISSN 1365-2664, Vol. 53, nr 3, s. 846-855Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    1. Understanding and predicting ecosystem responses to multiple environmental pressures is a long-standing interest in ecology and environmental management. However, few studies have examined how the functional features of freshwater biological communities vary along multiple gradients of environmental stress. Furthermore, modelling these functional features for a whole river network constitutes a strong potential basis to improve ecosystem management. 2. We explored how functional redundancy of biological communities (FR, a functional feature related to the stability, resistance and resilience of ecosystems) responds to single and multiple environmental filters. We compared these responses with those of functional richness, evenness and divergence. We used riparian vegetation of a Mediterranean basin, and three of the main environmental filters affecting freshwater communities in such regions, that is drought, flow regulation and agricultural intensity, thus considering the potential effect of natural environmental variability. We also assessed the predictability of FR and estimated it for the entire river network. 3. We found that all functional measures decreased with increasing environmental filter intensity. However, FR was more sensitive to single and multiple environmental filters compared to other functional measures. The best-fitting model explained 59% of the FR variability and included agriculture, drought and flow regulation and the pairwise interactions of agriculture with drought and flow regulation. The parameters of the FR models differed from null model expectations reflecting a non-random decline along stress gradients. 4. Synthesis and applications. We found non-random detrimental effects along environmental filters' gradients for riparian functional redundancy (the most sensitive functional index), meaning that increased stress could jeopardize stability, resistance and resilience of these systems. In general, agriculture caused the greatest impact on functional redundancy and functional diversity measures, being the most important stressor for riparian functionality in the study area. Temporary streams flowing through an agricultural, regulated basin had reduced values of functional redundancy, whereas the free-flowing medium-sized, perennial water courses flowing through unaltered sub-basins displayed higher values of functional redundancy and potentially greater stability against human impacts. All these findings along with the predicted basin-wide variation of functional redundancy can assist environmental managers in improving monitoring and ecosystem management.

  • 6.
    del Río, Miren
    et al.
    Instituto de Ciencias Forestales (ICIFOR), INIA, CSIC, Madrid, Spain.
    Pretzsch, Hans
    School of Life Sciences Weihenstephan, Technical University of Munich, Freising, Germany.
    Ruiz-Peinado, Ricardo
    Instituto de Ciencias Forestales (ICIFOR), INIA, CSIC, Madrid, Spain.
    Jactel, Hervé
    INRAE, University of Bordeaux, Biogeco, Cestas, France.
    Coll, Lluís
    EAGROF, University of Lleida, Lleida, Spain; Joint Research Unit CTFC-AGROTECNIO-CERCA, Solsona, Spain.
    Löf, Magnus
    Swedish University of Agricultural Sciences, Southern Swedish Forest Research, Lomma, Sweden.
    Aldea, Jorge
    Swedish University of Agricultural Sciences, Southern Swedish Forest Research, Lomma, Sweden.
    Ammer, Christian
    Silviculture and Forest Ecology of the Temperate Zones, University of Göttingen, Göttingen, Germany.
    Avdagić, Admir
    Faculty of Forestry, University of Sarajevo, Sarajevo, Bosnia and Herzegovina.
    Barbeito, Ignacio
    Department of Forest Resources Management, Faculty of Forestry, University of British Columbia, BC, Vancouver, Canada.
    Bielak, Kamil
    Institute of Forest Sciences, Warsaw University of Life Sciences, Warsaw, Poland.
    Bravo, Felipe
    Sustainable Forest Management Research Institute (iuFOR), University of Valladolid, Palencia, Spain; Unidad Asociada I+D+i al CSIC Gestión Forestal Sostenible, Palencia, Spain.
    Brazaitis, Gediminas
    Vytautas Magnus University, Department of Forest Science, Kaunas, Lithuania.
    Cerný, Jakub
    Forestry and Game Management Research Institute, Czech Republic.
    Collet, Catherine
    Université de Lorraine, AgroParisTech, INRAE, UMR Silva, Nancy, France.
    Condés, Sonia
    Universidad Politécnica de Madrid, Madrid, Spain.
    Drössler, Lars
    School of Natural Science and Engineering, Ilia State, University, Tbilisi, Georgia.
    Fabrika, Marek
    Technical University in Zvolen, Faculty of Forestry, Zvolen, Slovakia.
    Heym, Michael
    School of Life Sciences Weihenstephan, Technical University of Munich, Freising, Germany.
    Holm, Stig-Olof
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Hylen, Gro
    NIBIO, Norwegian Institute of Bioeconomy Research, Ås, Norway.
    Jansons, Aris
    Latvian State Forest Research Institute Silava, Salaspils, Latvia.
    Kurylyak, Viktor
    Ukrainian National Forestry University, L'viv, Ukraine.
    Lombardi, Fabio
    AGRARIA, Mediterranean University of Reggio Calabria, Reggio Calabria, Italy.
    Matović, Bratislav
    University of Novi Sad, Institute of Lowland Forestry and Environment, Novi Sad, Serbia; Faculty of Agriculture, University of East Sarajevo, East Sarajevo, Bosnia and Herzegovina.
    Metslaid, Marek
    Institute of Forestry and Rural Engineering, Estonian University of Life Sciences, Tartu, Estonia.
    Motta, Renzo
    DISAFA, University of Turin, Grugliasco, Italy.
    Nord-Larsen, Thomas
    IGN, University of Copenhagen, Frederiksberg C, Denmark.
    Nothdurft, Arne
    Department of Forest- and Soil Sciences, Institute of Forest Growth, University of Natural Resources and Life Sciences Vienna, Vienna, Austria.
    den Ouden, Jan
    Forest Ecology and Forest Management, Wageningen University of Environmental Sciences, Wageningen, Netherlands.
    Pach, Maciej
    Faculty of Forestry, University of Agriculture in Krakow, Kraków, Poland.
    Pardos, Marta
    Instituto de Ciencias Forestales (ICIFOR), INIA, CSIC, Madrid, Spain.
    Poeydebat, Charlotte
    Bordeaux Sciences Agro, University of Bordeaux, Gradignan, France.
    Ponette, Quentin
    UCLouvain, Earth & Life Institute, Louvain-la-Neuve, Belgium.
    Pérot, Tomas
    INRAE – UR EFNO - Centre de Recherche Val de Loire, Nogent-Sur-Vernisson, France.
    Reventlow, Ditlev Otto Juel
    IGN, University of Copenhagen, Frederiksberg C, Denmark.
    Sitko, Roman
    Technical University in Zvolen, Faculty of Forestry, Zvolen, Slovakia.
    Sramek, Vit
    Forestry and Game Management Research Institute, Czech Republic.
    Steckel, Mathias
    Forst Baden-Württemberg (AöR), Ulm-Wiblingen, Germany.
    Svoboda, Miroslav
    Faculty of Forestry and Wood Sciences, Czech University of Life Sciences, Prague, Czech Republic.
    Verheyen, Kris
    Forest & Nature Lab, Ghent University, Melle-Gontrode, Belgium.
    Vospernik, Sonja
    Department of Forest- and Soil Sciences, Institute of Forest Growth, University of Natural Resources and Life Sciences Vienna, Vienna, Austria.
    Wolff, Barbara
    Hochschule für Nachhaltige Entwicklung Eberswalde (HNEE), FG Waldinventur und Planung, Eberswalde, Germany.
    Zlatanov, Tzvetan
    Institute of Biodiversity and Ecosystem Research, Bulgarian Academy of Sciences, Sofia, Bulgaria.
    Bravo-Oviedo, Andrés
    Dpt. Biogeography and Global Change, MNCN – CSIC, Madrid, Spain.
    Emerging stability of forest productivity by mixing two species buffers temperature destabilizing effect2022Ingår i: Journal of Applied Ecology, ISSN 0021-8901, E-ISSN 1365-2664, Vol. 59, nr 11, s. 2730-2741Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The increasing disturbances in monocultures around the world are testimony to their instability under global change. Many studies have claimed that temporal stability of productivity increases with species richness, although the ecological fundamentals have mainly been investigated through diversity experiments. To adequately manage forest ecosystems, it is necessary to have a comprehensive understanding of the effect of mixing species on the temporal stability of productivity and the way in which it is influenced by climate conditions across large geographical areas. Here, we used a unique dataset of 261 stands combining pure and two-species mixtures of four relevant tree species over a wide range of climate conditions in Europe to examine the effect of species mixing on the level and temporal stability of productivity. Structural equation modelling was employed to further explore the direct and indirect influence of climate, overyielding, species asynchrony and additive effect (i.e. temporal stability expected from the species growth in monospecific stands) on temporal stability in mixed forests. We showed that by adding only one tree species to monocultures, the level (overyielding: +6%) and stability (temporal stability: +12%) of stand growth increased significantly. We identified the key effect of temperature on destabilizing stand growth, which may be mitigated by mixing species. We further confirmed asynchrony as the main driver of temporal stability in mixed stands, through both the additive effect and species interactions, which modify between-species asynchrony in mixtures in comparison to monocultures. Synthesis and applications. This study highlights the emergent properties associated with mixing two species, which result in resource efficient and temporally stable production systems. We reveal the negative impact of mean temperature on temporal stability of forest productivity and how the stabilizing effect of mixing two species can counterbalance this impact. The overyielding and temporal stability of growth addressed in this paper are essential for ecosystem services closely linked with the level and rhythm of forest growth. Our results underline that mixing two species can be a realistic and effective nature-based climate solution, which could contribute towards meeting EU climate target policies.

    Ladda ner fulltext (pdf)
    fulltext
  • 7.
    Engström, Johanna
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Nilsson, Christer
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Jansson, Roland
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Effects of stream restoration on dispersal of plant propagules2009Ingår i: Journal of Applied Ecology, ISSN 0021-8901, E-ISSN 1365-2664, Vol. 46, nr 2, s. 397-405Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    1. Species immigration is vital for the success of restoring degraded ecosystems, but the effectiveness of enhancing dispersal following restoration is seldom evaluated. Running water is an important vector for plant dispersal. Frequency and duration of floods and channel-network complexity are important factors influencing propagule dispersal. In Sweden, these functions have been modified by channelization to facilitate timber floating, thus hampering emigration and immigration of riparian propagules.

    2. During the last 10–20 years, affected watercourses have been restored by removing barriers and replacing boulders into channels. This is hypothesized to facilitate retention of water-dispersed propagules. We studied the efficiency of propagule retention following restoration by releasing propagule mimics and by placing propagule traps in the riparian zone.

    3. Retention of propagule mimics was highest in sites restored with boulders and large wood. Retention occurred at both high and low flows but was most efficient during low flows when mimics were trapped by boulders and wood. Waterborne propagules ending up at such sites are unlikely to establish unless they can reach the riparian zone later. At high flows, floating propagules are more likely to reach riparian areas suitable for establishment. According to propagule traps placed at various levels of the riparian zone, deposition of plant propagules and sediments did not increase in restored sites.

    4. Synthesis and applications. Our study not only demonstrates that restoration of channel complexity through replacement of boulders and wood can enhance retention of plant propagules, but also it highlights the importance of understanding how restoration effects vary with flow. Most streams are restored to function optimally during median or average flows, whereas communities often are controlled by ecological processes acting during extreme flow events. We advocate that stream restoration should be designed for optimal function during those discharges under which the ecological processes in question are most important, which in this case is, during high flow.

    Ladda ner fulltext (pdf)
    Engström et al_JAE2009
  • 8. Fournier, Auriel M. V.
    et al.
    Sullivan, Alexis R.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Bump, Joseph K.
    Perkins, Marie
    Shieldcastle, Mark C.
    King, Sammy L.
    Combining citizen science species distribution models and stable isotopes reveals migratory connectivity in the secretive Virginia rail2017Ingår i: Journal of Applied Ecology, ISSN 0021-8901, E-ISSN 1365-2664, Vol. 54, nr 2, s. 618-627Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    1. Stable hydrogen isotope (delta D) methods for tracking animal movement are widely used yet often produce low resolution assignments. Incorporating prior knowledge of abundance, distribution or movement patterns can ameliorate this limitation, but data are lacking for most species. We demonstrate how observations reported by citizen scientists can be used to develop robust estimates of species distributions and to constrain dD assignments. 2. We developed a Bayesian framework to refine isotopic estimates of migrant animal origins conditional on species distribution models constructed from citizen scientist observations. To illustrate this approach, we analysed the migratory connectivity of the Virginia rail Rallus limicola, a secretive and declining migratory game bird in North America. 3. Citizen science observations enabled both estimation of sampling bias and construction of bias-corrected species distribution models. Conditioning dD assignments on these species distribution models yielded comparably high-resolution assignments. 4. Most Virginia rails wintering across five Gulf Coast sites spent the previous summer near the Great Lakes, although a considerable minority originated from the Chesapeake Bay watershed or Prairie Pothole region of North Dakota. Conversely, the majority of migrating Virginia rails from a site in the Great Lakes most likely spent the previous winter on the Gulf Coast between Texas and Louisiana. 5. Synthesis and applications. In this analysis, Virginia rail migratory connectivity does not fully correspond to the administrative flyways used to manage migratory birds. This example demonstrates that with the increasing availability of citizen science data to create species distribution models, our framework can produce high-resolution estimates of migratory connectivity for many animals, including cryptic species. Empirical evidence of links between seasonal habitats will help enable effective habitat management, hunting quotas and population monitoring and also highlight critical knowledge gaps.

  • 9.
    Frainer, André
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap. Faculty of Biosciences, Fisheries and Economics, UiT The Arctic University of Norway, Tromsø, Norway; Norwegian Institute for Nature Research (NINA), Fram Centre, Tromsø, Norway.
    McKie, Brendan G.
    Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Uppsala, Sweden.
    The legacy of forest disturbance on stream ecosystem functioning2021Ingår i: Journal of Applied Ecology, ISSN 0021-8901, E-ISSN 1365-2664, Vol. 58, nr 7, s. 1511-1522Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Forest clearance is a pervasive disturbance worldwide, but many of its impacts are regarded as transient, diminishing in intensity as forest recovers. However, forests can take decades to centuries to recover after severe disturbances, and temporal lags in recovery of ecosystem properties for different forest habitats are mostly unknown. This includes forest streams, where most studies of the impacts of forest clearance are restricted to the first years of recovery, typically finding that temporary increases in light and nutrient run-off diminish as forest recovers. Implications of longer term changes remain little investigated.

    In a space-for-time substitution experiment, we assessed changes in organic matter processing and in the functional and taxonomic composition of litter-consuming detritivores along a riparian forest age gradient ranging from 1 to 120 years since last timber harvesting.

    Variation in organic matter processing and detritivore functional diversity along the forest succession gradient were both expressed as second-order polynomial relationships (peaking at ~50 years along the forest age gradient). Decomposition rates were lowest in both the more recently clear-cut and older riparian forest streams.

    Variation of litter decomposition rates among litter bags within streams, measured by the coefficient of variation, was lowest in recent clear-cuts and increased linearly along the succession gradient. This result indicates higher within-stream heterogeneity in decomposition rates in older forest streams.

    Synthesis and applications: We found that the decomposition of leaf litter, a component of carbon cycling in forests, was higher in streams flowing through intermediately aged forest, and that several key attributes of the organisms regulating litter decomposition also varied systematically with forest age. These findings highlight the longer term consequences of forest succession following forest clear-cutting for stream habitats. Our findings further illustrate complications arising from the use of forested sites as references for newly cleared sites without properly accounting for forest age, given conclusions regarding biotic responses will depend on the age of the reference forests. Finally, our results emphasise the potential of intensive forest management centred on vast, one-time clear-cutting events to drive long-term homogenisation not only in forest age structure but also in the functioning of associated forest stream habitats. ​.

    Ladda ner fulltext (pdf)
    fulltext
  • 10.
    Frainer, André
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap. Department of Arctic and Marine Biology, University of Tromsø, Tromsø, Norway.
    Polvi, Lina E.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Jansson, Roland
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    McKie, Brendan G.
    Enhanced ecosystem functioning following stream restoration: The roles of habitat heterogeneity and invertebrate species traits2018Ingår i: Journal of Applied Ecology, ISSN 0021-8901, E-ISSN 1365-2664, Vol. 55, nr 1, s. 377-385Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    1. Habitat restoration is increasingly undertaken in degraded streams and rivers to help improve biodiversity and ecosystem functioning. Follow-up assessments focused on outcomes for biodiversity have often found scant evidence for recovery, raising concerns about the efficacy of habitat restoration for improving ecological integrity. However, responses of other ecological variables, such as ecosystem process rates and the functional trait composition of biological assemblages, have been little evaluated.

    2. We assessed how the restoration of habitat heterogeneity affected multiple functional parameters in 20 boreal stream reaches encompassing both more and less extensively restored sites, as well as channelised and natural reference sites. We further assessed relationships between our functional parameters and a fluvial geomorphic measure of habitat heterogeneity.

    3. Leaf decomposition was positively related to habitat heterogeneity. This was associated with shifts in the functional composition of detritivore assemblages, with the most obligate litter consumers more prominent in reaches showing higher habitat heterogeneity. The deposition of fine particulate organic matter was consistently higher in restored than channelised sites, and was positively related to the heterogeneity gradient. Algal biomass accrual per unit area did not vary either with restoration or the heterogeneity gradient.

    4. Synthesis and applications. Our findings demonstrate that restoration of river habitat heterogeneity can enhance retention and decomposition of organic matter, key ecosystem properties underpinning ecosystem functioning and service delivery. Significantly, enhanced litter decomposition was linked with a change in the functional composition rather than diversity of detritivore assemblages. Future evaluation of the success of habitat restorations should incorporate quantification of ecosystem processes and the functional traits of biota, in addition to measures of fluvial geomorphology and more traditional biotic metrics, to facilitate a more comprehensive and mechanistic assessment of ecological responses.

  • 11.
    Hylander, Kristoffer
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Aspect modifies the magnitude of edge effects on bryophyte growth in boreal forests2005Ingår i: Journal of Applied Ecology, ISSN 0021-8901, E-ISSN 1365-2664, Vol. 42, nr 3, s. 518-525Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    1. The increased length of forest clear-cut edges is considered to be one of the main ecological consequences of silviculture. The effects vary over the landscape, and studies have shown that aspect is one important factor determining the extent of microclimatic edge effects across forest clear-cut boundaries. However, little is known about the relationship between contrasts in microclimate at edges and responses of ecological processes and biodiversity, such as growth, decomposition and species distributions.

    2. A field experiment was conducted in the boreal forest of northern Sweden to assess the effect of aspect at north- and south-facing edges using mosses as bioindicators. The growth of two species (Hylocomium splendens and Hylocomiastrum umbratum) was evaluated during one growing season. Samples of each species were planted in pots at eight north- and eight south-facing forest clear-cut edges.

    3. Growth increased exponentially with distance from the edge to the interior, and there was a significant effect both in north- and south-facing edges. The percentage decline in growth at the edge was larger in the south- than in the north-facing edges.

    4. The spatial extent of the edge effect, when measured at the point of 90% of interior growth, was similar between north- and south-facing edges, although it differed between the two species evaluated.

    5. Synthesis and applications. The difference in exposure to sunlight between north- and south-facing edges was shown to modify the magnitude of the growth of a poikilohydric organism at the very edge, but not the depth of the edge influence. Aspect should be taken into account in management plans for conservation of boreal forests. In the northern hemisphere, wider buffers of uncut forest should be left at the south side than at the north side of retained forest patches. Those forest interior species that are most sensitive to alterations in microclimate will, however, need equal protection from edge effects at all aspects.

  • 12.
    Malm, Lisa E.
    et al.
    School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, UK ; The James Hutton Institute, Aberdeen, UK.
    Pearce-Higgins, James W.
    Littlewood, Nick A.
    Karley, Alison J.
    Karaszewska, Ewa
    Jaques, Robert
    Pakeman, Robin J.
    Redpath, Stephen M.
    Evans, Darren M.
    Livestock grazing impacts components of the breeding productivity of a common upland insectivorous passerine: Results from a long-term experiment2020Ingår i: Journal of Applied Ecology, ISSN 0021-8901, E-ISSN 1365-2664, Vol. 57, nr 8, s. 1514-1523Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    1. The intensity of pastoral management in areas of High Nature Value farming is declining in some regions of Europe but increasing in others. This affects open habitats of conservation concern, such as the British uplands, where bird species that benefit from low-intensity grazing may be most sensitive to such polarization. While experimental manipulations of livestock grazing intensities have improved our understanding of upland breeding bird responses in the short term, none have examined the long-term impacts of altered management on reproductive success.

    2. Using a replicated landscape-scale experiment that started in 2003, we investigated the effects of four grazing treatments (intensive sheep; low-intensity sheep; low-intensity mixed sheep and cattle; and no grazing) on the breeding productivity of meadow pipits Anthus pratensis, the most common upland passerine. Surveys were carried out systematically during early (2003 and 2004) and late (2015 and 2016) sampling periods of the experiment to compare the short- and long-term effects of grazing treatments on breeding density and productivity of pipits specifically, but also on the overall bird community.

    3. Pipit breeding density was lowest under low-intensity sheep grazing while the highest egg-stage nest survival was observed in the same treatment, although no significant treatment effects were detected on overall nest survival or fledgling output. There were no significant differences in treatment effects between the sampling periods on any breeding variable, but overall nest survival was lower in the later sampling period across all treatments.

    4. Breeding bird species richness differed between treatments in the later sampling period, with highest species richness in the ungrazed treatment.

    5. Synthesis and applications. Livestock grazing management can have different outcomes for different upland birds. Our results showed that, with time, meadow pipit breeding productivity tended to be higher when sheep grazing intensity was reduced and/or mixed with cattle, and lower when livestock were removed, but not significantly so. Removal of grazing, however, can significantly increase bird species richness. The long-term experiment showed an overall decline in fledglings regardless of grazing treatments, potentially a result of increased predator numbers harboured by nearby developing woodland, highlighting the importance of considering wider landscape processes in grazing management decisions.

    Ladda ner fulltext (pdf)
    fulltext
  • 13.
    Malm-Renöfält, Birgitta
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Merritt, David M.
    Nilsson, Christer
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Connecting variation in vegetation and stream flow: the role of geomorphic context in vegetation response to large floods along boreal rivers2007Ingår i: Journal of Applied Ecology, ISSN 0021-8901, E-ISSN 1365-2664, Vol. 44, nr 1, s. 147-157Artikel i tidskrift (Refereegranskat)
    Abstract [en]
    1. Flooding governs riparian plant diversity along boreal rivers but the ecological role of extreme floods is only partly understood. We studied the dynamics of riparian plant composition and richness in the free-flowing Vindel River in northern Sweden, and the importance of reach type in sustaining high species richness.
    2. We conducted three surveys of riparian plant species richness over a period of two decades. The first and last of these surveys were conducted 1–3 years after significant flooding and the second was carried out after a period of more moderate flooding.
    3. Our results suggest that extreme floods reduce riparian plant species richness in tranquil (slow-flowing) reaches but that a subsequent period of less extreme flood events facilitates recovery. Tranquil river reaches were also more prone to invasion by ruderal species following major floods. Species richness in turbulent reaches (rapids and runs) remained constant during all surveys. One possible explanation for this pattern is that tranquil reaches become more anoxic during floods because they have more fine-grade soils with lower hydraulic conductivity than turbulent reaches. Anoxic conditions may cause stress and plant death, opening up space for colonization. Turbulent reaches maintain a better oxygenation in the root zone of plants through high groundwater turnover, reducing negative effects of prolonged floods.
    4. The fact that turbulent reaches preserved species richness regardless of flood magnitude suggests that they are important for the resistance of riparian ecosystems to prolonged inundation. In contrast, tranquil reaches, with a higher water-holding capacity, might instead maintain their species richness during drought periods.
    5. Synthesis and applications. Our findings highlight the importance of spatial and temporal variation in riverine plant species richness and composition. To conserve these habitats at a landscape scale, a full range of reach types is necessary to allow for recovery in reaches where species richness has declined. To maintain healthy riparian zones, river managers should focus restoration efforts on interactions between hydrology, geomorphology and biota.
  • 14.
    McKie, Brendan G.
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Petrin, Zlatko
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Malmqvist, Björn
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Mitigation or disturbance? Effects of liming on macroinvertebrate assemblage structure and leaf-litter decomposition in the humic streams of northern Sweden2006Ingår i: Journal of Applied Ecology, ISSN 0021-8901, E-ISSN 1365-2664, Vol. 43, nr 4, s. 780-791Artikel i tidskrift (Refereegranskat)
    Abstract [en]
    1. Stream liming can alleviate the effects of anthropogenic acidification but itself constitutes a substantial ecosystem-level perturbation. Acidity in the humic streams of northern Sweden largely arises from natural causes but liming is extensively practised, with uncertain ecological outcomes.
    2. We investigated macroinvertebrate assemblage structure and leaf-litter decomposition in seven humic Swedish streams, each of which is limed at a single point using a dosing tower. Grey alder Alnus incana leaves were enclosed in replicate fine (mesh size 0·5 mm) and coarse (10 mm) mesh bags at three locations in each stream: upstream of the dosing tower, in the transitional ‘mixing zone’ immediately downstream of the tower, and at a site further downstream where the lime powder is completely dissolved, with marked changes to water chemistry. Benthic macroinvertebrate assemblages were characterized from each site via five replicate Surber samples.
    3. Alkalinity, pH, conductivity and calcium (Ca) concentrations increased following liming, whereas dissolved organic carbon and aluminium concentrations decreased.
    4. Decomposition in fine mesh bags, primarily mediated by microbes, was positively associated with pH and Ca and was significantly elevated by liming, probably attributable to stimulation of fungal pectin-degrading enzymes that require Ca as a cofactor.
    5. Decomposition attributable to detritivorous insects (shredders), assessed by subtracting decomposition observed in fine mesh bags from that observed in coarse bags, was reduced following liming, in concert with changes to shredder assemblages. Abundance of large caddisfly shredders declined in limed stream sections, whereas some smaller stoneflies increased in number. Shredder diversity declined following liming during spring. Species evenness fell overall, and richness was reduced in four of six streams.
    6. Synthesis and applications. Water chemistry changes following stream liming in northern Sweden appear to overcompensate for the limited acid deposition observed in the region, with important ecosystem consequences. The potential deleterious impacts of liming need to be balanced against its desired outcomes in regions where acidity is largely attributable to natural causes.
  • 15.
    Sarneel, Judith M.
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Janssen, Roel H.
    Rip, Winnie J.
    Bender, Irene M. A.
    Bakker, Elisabeth S.
    Windows of opportunity for germination of riparian species after restoring water level fluctuations: a field experiment with controlled seed banks2014Ingår i: Journal of Applied Ecology, ISSN 0021-8901, E-ISSN 1365-2664, Vol. 51, nr 4, s. 1006-1014Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    1. Restoration activities aiming at increasing vegetation diversity often try to stimulate both dispersal and germination. In wetlands, dispersal and germination are coupled as water and water level fluctuations (WLF) simultaneously influence seed transport and germination conditions (soil moisture). Water regime shifts have been shown to affect vegetation composition. However, the interactions between WLF, dispersal and subsequent germination as drivers of such changes are still poorly understood, especially within the complexity of a field situation.

    2. We tested the effect of soil moisture on ten riparian species in the greenhouse and sowed these species on 135 field locations in nine wetlands with recently restored WLF. We used quantile regressions to test the effects of WLF on the window of opportunity for germination from sown seeds and other seeds naturally dispersed to our plots, as well as on community diversity.

    3. Soil moisture significantly affected germination both in the greenhouse and in the field. In the complexity of a field situation, a flooding depth just below the soil level, an intermediate flooding duration and a high flooding frequency provided the best opportunities for maximal germination. This was because these conditions enhanced germination from the seed bank as well as increasing germination from dispersed seeds. Seedling diversity showed identical patterns.

    4. Other known (i.e., light conditions) and unknown factors played a role as we found low and variable germination, even under optimal conditions. We found evidence that WLF can affect vegetation zonation as flooded seedling communities contained more species with high moisture affinity.

    5. Synthesis and applications. Water level fluctuations provide clear windows of opportunity for germination both from the seed bank and from dispersed seeds. Water regime changes are therefore likely to strongly affect recruitment opportunities and subsequent community assembly in riparian ecosystems, for instance through climate change or management. Water level fluctuations can be used as management tool to stimulate plant recruitment and seedling diversity in riparian wetlands.

  • 16.
    Schwieger, Sarah
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap. Experimental Plant Ecology, Institute of Botany and Landscape Ecology, Greifswald University, Greifswald, Germany.
    Kreyling, Juergen
    Experimental Plant Ecology Institute of Botany and Landscape Ecology, Greifswald University Greifswald Germany.
    Peters, Bo
    Experimental Plant Ecology Institute of Botany and Landscape Ecology, Greifswald University Greifswald Germany.
    Gillert, Alexander
    Fraunhofer Institute for Computer Graphics Research IGD Rostock Germany.
    Freiherr von Lukas, Uwe
    Fraunhofer Institute for Computer Graphics Research IGD Rostock Germany.
    Jurasinski, Gerald
    Faculty of Agriculture and Environmental Sciences University of Rostock Rostock Germany.
    Köhn, Daniel
    Faculty of Agriculture and Environmental Sciences University of Rostock Rostock Germany.
    Blume-Werry, Gesche
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap. Experimental Plant Ecology Institute of Botany and Landscape Ecology, Greifswald University.
    Rewetting prolongs root growing season in minerotrophic peatlands and mitigates negative drought effects2022Ingår i: Journal of Applied Ecology, ISSN 0021-8901, E-ISSN 1365-2664, Vol. 59, nr 8, s. 2106-2116Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Root phenology influences the timing of plant resource acquisition and carbon fluxes into the soil. This is particularly important in fen peatlands, in which peat is primarily formed by roots and rhizomes of vascular plants. However, most fens in Central Europe are drained for agriculture, leading to large carbon losses, and further threatened by increasing frequency and intensity of droughts. Rewetting fens aims to restore the original carbon sink, but how root phenology is affected by drainage and rewetting is largely unknown.

    We monitored root phenology with minirhizotrons in drained and rewetted fens (alder forest, percolation fen and coastal fen) as well as its soil temperature and water table depth during the 2018 drought. For each fen type, we studied a drained site and a site that was rewetted ~25 years ago, while all the sites studied had been drained for almost a century.

    Overall, the growing season was longer with rewetting, allowing roots to grow over a longer period in the year and have a higher root production than under drainage. With increasing depth, the growing season shifted to later in time but remained a similar length, and the relative importance of soil temperature for root length changes increased with soil depth.

    Synthesis and applications: Rewetting extended the growing season of roots, highlighting the importance of phenology in explaining root productivity in peatlands. A longer growing season allows a longer period of carbon sequestration in form of root biomass and promotes the peatlands' carbon sink function, especially through longer growth in deep soil layers. Thus, management practices that focus on rewetting peatland ecosystems are necessary to maintain their function as carbon sinks, particularly under drought conditions, and are a top priority to reduce carbon emissions and address climate change.

    Ladda ner fulltext (pdf)
    fulltext
  • 17.
    Åström, Marcus
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Dynesius, Mats
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Hylander, Kristoffer
    Nilsson, Christer
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Effects of slash harvest on bryophytes and vascular plants in southern boreal forest clear-cuts2005Ingår i: Journal of Applied Ecology, ISSN 0021-8901, E-ISSN 1365-2664, Vol. 42, nr 6, s. 1194-1202Artikel i tidskrift (Refereegranskat)
1 - 17 av 17
RefereraExporteraLänk till träfflistan
Permanent länk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf