| 1. |
- Lindbladh, Matts, et al.
(författare)
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Avian diversity in Norway spruce production forests – How variation in structure and composition reveals pathways for improving habitat quality
- 2017
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Ingår i: Forest Ecology and Management. - : Elsevier BV. - 0378-1127 .- 1872-7042. ; 397, s. 48-56
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Tidskriftsartikel (refereegranskat)abstract
- Forests used for timber production provide essential ecosystem services to society, as well as potential breeding habitat for bird communities. In southern Sweden, 90% of productive forest land is used for timber production and stands dominated by Norway spruce (Picea abies) constitute approximately 40% of the forested area. Due to their homogeneous structure, these spruce production forests are often regarded as depauperate. Despite this perception, knowledge about the biodiversity found in these stands is scarce. Here we synthesize the results of four separate bird surveys conducted within 35 spruce production stands of southern Sweden. The results are compared to recent population trends within the general study area. In total 49 bird species were recorded, with a strong difference in species composition between newly planted clear-cuts (forest age <15 years) and forests older than 15 years. The majority of species encountered in the older forest category were common forest birds, with a single red-listed species among the regularly occurring species. In contrast, three red-listed “farmland species” were frequently encountered in the newly planted forests, revealing the capacity of those birds preferring open and recently disturbed habitats to utilize clear-cuts. A higher diversity of tree sizes and the inclusion of even relatively small proportions (<15%) of broadleaved tree species had a positive effect on bird species richness. Several species encountered in spruce production forests are declining in numbers, but it is not clear whether these stands are acting as source or sink environments for their populations. However, our results indicate that relatively small adjustments to spruce forest management should improve the quality of this widespread habitat.
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| 2. |
- Liljebäck, Niklas, et al.
(författare)
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Learning from long time series of harvest and population data : Swedish lessons for European goose management
- 2021
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Ingår i: Wildlife Biology. - : Nordic Council for Wildlife Research (NKV). - 0909-6396 .- 1903-220X. ; 1, s. 1-10
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Recension (refereegranskat)abstract
- Goose management in Europe is faced by multiple challenges, as some species are declining and in need of conservation actions, while other populations have become very abundant, resulting in calls for increased harvest. Sweden has long-term series of harvest data and counts of breeding and autumn-staging geese. We used national data (indices) for greylag goose, bean goose and Canada goose to study shifts in temporal trends and correlative patterns, and to infer possible causal links between harvest and population trends. Our study provides an opportunity to guide management given the data collected within the present monitoring, as well as to suggest improvements for future data collection. The populations of greylag and Canada geese increased in Sweden 1979–2018, but this long-term trend included a recent decrease in the latter species. Bean goose breeding index decreased, whilst staging numbers and harvest varied with no clear long-term trend. For Canada goose, our analysis suggests that harvest may affect population growth negatively. For bean goose and greylag goose we could not detect any effect of harvest on autumn counts the following year. We find that the present data and analysis of coherence may suffice as basis for decisions for the current management situation in Sweden with its rather unspecific goals for greylag (very abundant) and Canada goose (invasive species) populations. However, for management of bean geese, with international concerns of over harvest, data lack crucial information. For future management challenges, with more explicit goals, for all goose species we advocate information that is more precise. Data such as hunting effort, age-structure of goose populations and mark–recapture data to estimate survival and population size, is needed to feed predictive population models guiding future Swedish and European goose management.
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| 3. |
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| 4. |
- Gamero, Anna, et al.
(författare)
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Tracking Progress Toward EU Biodiversity Strategy Targets : EU Policy Effects in Preserving its Common Farmland Birds
- 2017
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Ingår i: Conservation Letters. - : Wiley. - 1755-263X. ; 10:4, s. 395-402
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Tidskriftsartikel (refereegranskat)abstract
- Maximizing the area under biodiversity-related conservation measures is a main target of the European Union (EU) Biodiversity Strategy to 2020. We analyzed whether agrienvironmental schemes (AES) within EU common agricultural policy, special protected areas for birds (SPAs), and Annex I designation within EU Birds Directive had an effect on bird population changes using monitoring data from 39 farmland bird species from 1981 to 2012 at EU scale. Populations of resident and short-distance migrants were larger with increasing SPAs and AES coverage, while Annex I species had higher population growth rates with increasing SPAs, indicating that SPAs may contribute to the protection of mainly target species and species spending most of their life cycle in the EU. Because farmland birds are in decline and the negative relationship of agricultural intensification with their population growth rates was evident during the implementation of AES and SPAs, EU policies seem to generally attenuate the declines of farmland bird populations, but not to reverse them.
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| 5. |
- Green, Martin, et al.
(författare)
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Häckande fåglar i Värmlands län : Trender för arter samt miljöindikatorer baserade på standardrutter och nattrutter
- 2020
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Rapport (populärvet., debatt m.m.)abstract
- Systemet med systematiskt utlagda standardrutter utgör ryggraden i den generella nationella och regionala miljöövervakningen av fåglar. I Värmlands län återfinns 34 av landets 716 standardrutter (knappt 5 %). I denna rapport redovisas utvecklingen för länets generella fågelfauna under perioden 1998–2019, även om vi också redovisar trender för perioderna 2002–2019 och 2010–2019. Den förstnämnda perioden är den längsta möjliga som vi kan beräkna trender för. Trenderna från 2002 och framåt täcker den period när vi har bättre årlig regional täckning generellt i landet. Den avslutande perioden täcker de senaste tio åren och används för att visa hur det går just nu, eller snarare hur det har gått i det allra senaste.Under 2010-talet har täckningen av länets standardrutter varit mycket god och motsvarande 62–100 % (medel 81 %) av de regionala rutterna har inventerats årligen. Detta är en lämplig fortsatt ambitionsnivå för att kunna ha en god övervakning av länets allmänna fåglar. Den goda täckningen av länet är helt beroende av att Länsstyrelsen och Naturvårdsverket finansierar fältinsatserna. Ungefär hälften av den årliga inventeringsinsatsen i länet bekostas av Länsstyrelsen och den andra hälften direkt av centrala anslag från Naturvårdsverket.Med startår 1998 är det 79 arter som setts näst intill årligen (minst 20 av 22 år) på länets standardrutter. Av dessa ökade 19 arter (24 %) och minskade 15 arter (19 %) säkert i antal. 25 arter (32 %) uppvisade stabila bestånd och för 20 arter (25 %) var utvecklingen osäker. Sett enbart till trendernas riktning, oavsett statistisk säkerhet, var det en övervikt (61 %) för arter med positiv trendriktning.Från 2002 är det 87 arter som bokförts på Värmlands standardrutter under nästan alla år (minst 16 av 18 år). Från detta startår var det övergripande mönstret mera negativt; bara sex arter (7 %) ökade medan 15 (17 %) minskade säkert i antal. 25 arter (29 %) hade stabila bestånd och för 41 arter (47 %) var utvecklingen osäker. Om vi enbart ser till trendriktningarna, oavsett statistisk säkerhet, var det under denna period en övervikt (62 %) för negativa trendriktningar, vilket förstärker bilden av ett mer negativt mönster från 2002–2019 än 1998–2019.De senaste tio åren (2010–2019) har 105 arter setts nära nog årligen (minst åtta av tio år) på standardrutterna i Värmlands län. Under denna korta period har pendeln svängt tillbaka åt det positiva hållet igen. I korttidsperspektivet är det 19 arter (18 %) som uppvisar säkra ökningar och blott två arter (2 %) med säkra minskningar. Sex arter (6 %) har haft stabila bestånd de senaste tio åren och för 78 arter (74 %) är beståndsutvecklingen osäker under denna period. Här måste en komma ihåg att den korta tidsperioden gör det svårare att få fram statistiskt säkra resultat. Därmed är det ofrånkomligt att andelen osäkra resultat är hög. Återigen var det nu en övervikt (64 %) av positiva trendriktningar om vi bortser från statistisk säkerhet och enbart tittar på själva riktningarna. Sedan 2011 har 17 olika nattrutter inventerats i Värmlands län, men det är enbart de fyra senaste åren, 2016–2019, som ett högre antal nattrutter har inventerats årligen. Detta tack vare Länsstyrelsens engagemang med att hitta lokala inventerare till länets nattrutter. Under dessa år har 12–16 rutter (medel 14) inventerats per år. Det är därför för denna väldigt korta period som vi redovisar lite mer detaljerade nattruttsresultat. Baserat på nattruttsdata presenterar vi utvecklingen för 33 utvalda fågel- och elva däggdjursarter som noterats på rutterna under minst två av de senaste fyra åren. Här ingår exempelvis sju olika ugglearter. Inga djupare slutsatser ska såklart dras från en så kort period som enbart fyra år, men vi kan konstatera att fyra ugglearter har bokförts årligen i länet. Dessa är katt-, slag-, horn- och pärluggla. För kattuggla är Värmlands län ett av de som hittills uppvisat de högsta noterade antalen per rutt. Vi kan också konstatera 2017 av allt att döma var ett gott gnagarår med goda registrerade uggleantal. En annan intressant nattaktiv fågelart är nattskärran, och precis som i landet i stort förefaller det gå bra för den arten i Värmland just nu. Flertalet bokförda däggdjursarter uppvisar positiva mönster på länets nattrutter under de senaste fyra åren.Indikatorer, gemensamma trender för grupper av fåglar, visar generellt sett på få statistiskt säkra förändringar i Värmlands län under perioden 2002–2019. I skogen finns tecken på en positiv utveckling, mest så under de allra senaste tio åren, men utan statistisk säkerhet. Mest positiv är till synes utvecklingen för fågelarter knutna till äldre skog. Även om statistiskt säkra resultat saknas så antyder mönstren i Värmlands län en betydligt mer positiv regional utveckling än den som finns för landet som helhet.Indikatorerna för odlingslandskapet visar på säkra minskningar över hela perioden 2002–2019, precis som i landet i stort. De senaste tio åren finns inga säkra förändringar, men dock små tecken på en regional uppgång. Dessa tecken är klart starkare i Värmlands län än i Sverige totalt sett.När det gäller våtmarker uppvisar de regionala indikatorerna tydligt positiva mönster som dock inte är statistiskt säkerställda. Tydligast positiva är trenderna under de senaste tio åren. Utvecklingen i Värmlands län är till synes mer positiv än den i hela Sverige. För sjöar och vattendrag har läget varit stabilt sett över hela perioden 2002–2019. Ett svagt positivt mönster finns för de senaste tio åren. I hela Sverige finns en säker ökning i korttidsperspektivet.De två indikatorerna som kopplar till biologisk mångfald i stort ger delvis lite olika utfall för Värmlands län, även om skillnaderna egentligen inte är så stora. En ena visar på en säker minskning över hela perioden 2002–2019, vilken den andra inte gör. Bakom detta finns för båda ett negativt mönster för hela perioden och ett lite positivt sådant för de senaste tio åren. På en generell nivå stämmer detta med hur det ser upp på nationell nivå. Där finns en statistiskt säker minskning för hela perioden men en lika säker ökning de senaste tio åren.Indikatorn som kopplar till effekterna av klimatförändring visar att det värmländska fågelsamhället har blivit ”varmare” under de senaste 18 åren. Detta innebär arter med varmare utbredningsområden relativt sett har haft en mer positiv utveckling än arter med kallare utbredningsområden. Med andra ord kan vi redan nu se att den värmländska fågelfaunan förändrats i takt med ett allt varmare klimat.
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| 6. |
- Smith, Henrik, et al.
(författare)
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Consequences of organic farming and landscape heterogeneity for species richness and abundance of farmland birds.
- 2010
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Ingår i: Oecologia. - : Springer Science and Business Media LLC. - 1432-1939 .- 0029-8549. ; 162:4, s. 1071-1079
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Tidskriftsartikel (refereegranskat)abstract
- It has been suggested that organic farming may benefit farmland biodiversity more in landscapes that have lost a significant part of its former landscape heterogeneity. We tested this hypothesis by comparing bird species richness and abundance during the breeding season in organic and conventional farms, matched to eliminate all differences not directly linked to the farming practice, situated in either homogeneous plains with only a little semi-natural habitat or in heterogeneous farmland landscapes with abundant field borders and semi-natural grasslands. The effect of farm management on species richness interacted with landscape structure, such that there was a positive relationship between organic farming and diversity only in homogeneous landscapes. This pattern was mainly dependent on the species richness of passerine birds, in particular those that were invertebrate feeders. Species richness of non-passerines was positively related to organic farming independent of the landscape context. Bird abundance was positively related to landscape heterogeneity but not to farm management. This was mainly because the abundance of passerines, particularly invertebrate feeders, was positively related to landscape heterogeneity. We suggest that invertebrate feeders particularly benefit from organic farming because of improved foraging conditions through increased invertebrate abundances in otherwise depauperate homogeneous landscapes. Although many seed-eaters also benefit from increased insect abundance, they may also utilize crop seed resources in homogeneous landscapes and conventional farms. The occurrence of an interactive effect of organic farming and landscape heterogeneity on bird diversity will have consequences for the optimal allocation of resources to restore the diversity of farmland birds.
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| 7. |
- Tayleur, Catherine, et al.
(författare)
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Impact of climate change on communities: revealing species' contribution.
- 2013
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Ingår i: Journal of Animal Ecology. - : Wiley. - 1365-2656 .- 0021-8790. ; 82:3, s. 551-561
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Tidskriftsartikel (refereegranskat)abstract
- Although climate is known to play an important role in structuring biological communities, high-resolution analyses of recent climatic impacts on multiple components of diversity are still sparse. Additionally, there is a lack of knowledge about which species drive community response to environmental change. We used a long-term breeding bird data set that encompasses a large latitudinal and altitudinal range to model the effect of temperature on spatial and temporal patterns in alpha and beta diversity. We also established a novel framework for identifying species-specific contributions to these macroecological patterns, hence combining two different approaches for identifying climatic impacts. Alpha diversity increased over time, whilst beta diversity declined; both diversity metrics showed a significant relationship with recent temperature anomalies. By partitioning beta diversity, we showed that the decline was predominately driven by changes in species turnover rather than nestedness suggesting a process of replacement by more common species. Using jackknife analyses we identified how individual species influenced the modelled relationships of diversity with temperature and time. Influential species tended to be habitat generalists with moderate to large distributions. We demonstrate that different facets of avian diversity can respond rapidly to temperature anomalies and as a result have undergone significant changes in the last decade. In general, it appears that warming temperatures are driving compositional homogenization of temperate bird communities via range expansion of common generalist species.
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| 8. |
- Ram, Dafne, et al.
(författare)
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What drives current population trends in forest birds – forest quantity, quality or climate? A large-scale analysis from northern Europe
- 2017
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Ingår i: Forest Ecology and Management. - : Elsevier BV. - 0378-1127 .- 1872-7042. ; 385, s. 177-188
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Tidskriftsartikel (refereegranskat)abstract
- Changes in forestry practices and on-going climate change may both have large impacts on forest bird populations. However, large-scale analyses of the effects of temporal changes in forest structure on forest bird numbers are largely lacking. We compared temporal trends from two Swedish nationwide long-term monitoring schemes, the Swedish Bird Survey (1998–2015) and the Swedish National Forestry Inventory (1983–2014), giving representative values for both forest and bird changes over an area of 35 million ha. Since 1998 the total area of middle-aged and mature forest increased by 6.4%. In parallel, several forest structures potentially beneficial to birds (dead wood, retention trees on clear cuts, multi-layer forests, old forest and broadleaved forest) increased somewhat in abundance, most likely as a result of legislation changes and increasing areas under forest certification schemes. Summer temperatures also increased, with warm summers dominating since 2002. In 1998–2015, the population sizes of 58 forest bird species on average increased, as did the number of species observed per route, with no general difference between forest specialists (16 species) and generalists (42 species). However, from around 2005, the positive trends in bird numbers and many forest structures have levelled out. An analysis of species population trends in relation to a measure of climate sensitivity (Species Temperature Index, STI) suggested that forest birds, just like Swedish birds in general, have indeed been affected by a warming climate. But given their STI, forest birds on average had more positive trends than non-forest birds, suggesting that other factors than climate have affected them positively. Strong candidate factors are the documented changes in forest quality and quantity. Whereas our data and analyses are correlational, and no firm conclusions on causality therefore can be drawn, it is reasonable to assume that the recent increases in forest quantity, forest quality, and summer temperatures, all have contributed to the general increase in forest bird numbers in Sweden. But the relative contribution of these driving forces remains to be determined. When it comes to the potentially positive effects of improving forest quality in terms of increases in old forest, stratification, retention trees and dead wood, it is noteworthy that many of the positive trends in forest structures since the mid-1990s seem to have ceased recently.
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| 9. |
- Andersson, G., et al.
(författare)
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Arthropod populations in a sub-arctic environment facing climate change over a half-century: variability but no general trend
- 2022
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Ingår i: Insect Conservation and Diversity. - : Wiley. - 1752-458X .- 1752-4598. ; 15:5, s. 534-542
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Tidskriftsartikel (refereegranskat)abstract
- Dramatic declines of some arthropod populations have recently received a lot of attention. Identified declines have mainly been attributed to changes in agriculture, climate, pathogen prevalence and light pollution, as well as cross-regional effects of, e.g., drifting pesticides. However, the overall picture is complex and debated, and there is a need for systematically collected long-term data, not least from areas relatively unaffected by humans. We monitored the abundance of arthropods (mainly insects) in subalpine birch forest in Swedish Lapland over a period of 53 years (1968-2020), in an area comparatively unaffected by human activities. Arthropod abundance was assessed by yearly systematic counts on 24,000 birch shoots, in the second half of June. Animals were categorised into 17 different groups directly upon counting, dependent on taxonomy and life stage (imago, larva). Overall, there was no significant change in arthropod numbers. Nor did estimates of the total biomass of arthropods (using group-specific indices of the mass of individuals) show any significant trend. Accordingly, there are no signs that the arthropod abundance or biomass on birch in this subarctic study site has gone through the same declines as have been reported from sites in other habitats. The reason may be that the impact of factors identified worldwide as drivers of arthropod declines so far are small or non-existent because of the low human population density in this area.
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| 10. |
- Green, Martin, et al.
(författare)
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Övervakning av fåglarnas populationsutveckling: : Årsrapport för 2022
- 2023
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- We present the results of the Swedish Bird Survey, a project run by the Department of Biology, Lund University, as a part of the National Monitoring Programme of the Swedish Environmental Protection Agency. The results for 2022 include data from: 546 winter point counts in 2021/2022 (47th winter), ofwhich 254 were carried out during the Christmas/New Year count, 209 summer point count routes (48th year) and 375 Fixed routes (27th year). In the programme for covering night-active birds (13 th season), 155 routes were covered on up to three occasions each (March, April and June). In addition, 425waterbird routes (8th season) and 186 archipelago squares (8th season) were surveyed. In the waterbird counts included in the International Waterbird Census (IWC) 219 sectors were counted in September (49 th year) and 1084 sectors in January (57th year). In total 740 persons were involved in the surveysreported here.Population trends were analyzed using TRIM and trends for 224 different bird species are presented, as well as the geographical distributions of the covered routes. Larger mammals are counted on the Night routes and the Fixed routes since 2010 and 2011, respectively, and we present trends for 12 mammal species based on these two systems. We also present trends from the schemes of water- and archipelago birds, through which we can follow yet more species with systematic counts during the breeding period.The long-term trends show both winners and losers among the Swedish birds. The species with the strongest declines during the breeding season are Eurasian Wigeon, Common Pochard, Common Eider, Common Shelduck, Northern Lapwing, Eurasian Curlew, Common Sandpiper, Ruff, European Herring Gull, Common Swift, Common House and Sand Martin, Hooded Crow, Marsh and Willow Tit, Common Reed Warbler, Common Starling, Yellowhammer and Ortolan Bunting. The strongest increases are found in Great Cormorant, Gadwall, Grey-lag Goose, Whooper Swan, Red Kite, White-tailed Eagle, Western Marsh Harrier, Common Crane, Eurasian Blue Tit, Eurasian Blackcap, southern Common Chiffchaff and European Goldfinch.Based on 187 taxa recorded on the Fixed routes over the last 10 years, there are more species significantly increasing in numbers (29%), than decreasing in numbers (15%). For the remaining species (56%), no statistically significant changes were recorded during the last ten years. Eurasian Skylark and Common Linnet has increased strongly in the last decade following long-term declines.After a long period of relative stability, Barn Swallow has decreased markedly in numbers in recent years.Based on the winter point counts, also here there are more positive than negative trends for the last ten years. In total 27% of 114 species have increased significantly, while 19% have decreased. For waterbirds specifically and based on the IWC counts in January, the majority of the surveyed species (70%) have increased in winter during the last ten years and only 7% of the species have decreased significantly.
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