Combined threats of climate change and land use to boreal protected areas with red-listed forest species in Finland

Peer reviewe

Predicting valuable forest habitats using an indicator species for biodiversity

Intensive management of boreal forests impairs forest biodiversity and species of old-growth forest. Effective measures to support biodiversity require detection of locations valuable for conservation. We applied species distribution models (SDMs) to a species of mature forest, the northern goshawk (Accipiter gentilis, goshawk), that is often associated with hotspots of forest biodiversity. We located optimal sites for the goshawk on a landscape scale, assessed their state under intensified logging operations and identified characteristics of goshawks' nesting sites in boreal forests. Optimal sites for the goshawk covered only 3.4% of the boreal landscape and were mostly located outside protected areas, which highlights the importance of conservation actions in privately-owned forests. Furthermore, optimal sites for the goshawk and associated biodiversity were under threat. Half of them were logged to some extent and 10% were already lost or notably deteriorated due to logging shortly after 2015 for which our models were calibrated. Habitat suitability for the goshawk increased with increasing volume of Norway spruce (Picea abies) peaking at 220 m(3) ha(-1), and with small quantities of birches (Betula spp.) and other broad-leaved trees. Threats to biodiversity of mature spruce forests are likely to accelerate in the future with increasing logging pressures and shorter rotation periods. Logging should be directed less to forests with high biodiversity. Continuous supply of mature spruce forests in the landscape should be secured with a denser network of protected areas and measures that aid in sparing large entities of mature forest on privately-owned land.peerReviewe

Suojelualueverkon merkitys metsälajistolle: lehtojen putkilokasvit, metsien lahopuukovakuoriaiset, havu- ja sekametsien linnut

Tämä raportti on osa Suomen ympäristökeskuksen luonto- ja maankäyttöyksikön luonnonsuojelualueverkon edustavuuden arviointi (SAVA) -hanketta. Raportti koostuu kolmesta erillisestä tutkimuksesta, jotka käsittelevät olemassa olevan luonnonsuojelualueverkon sekä vahvistettujen suojeluohjelmien merkitystä metsien lajistollisen monimuotoisuuden säilyttämisessä. Tutkimusten perusteella metsien suojelualueiden määrä ja kokonaisala, erityisesti Etelä-Suomessa, on riittämätön turvaamaan lajiston monimuotoisuuden säilymisen. Pohjois-Suomen laaja metsien suojelualueverkkoon perusteltu siellä esiintyvän lajiston turvaamiseksi, mutta sen avulla ei voida säilyttää levinneisyydeltään eteläistä lajistoa. Metsien suojeluohjelmien kohteet on valittu yleensä hyvillä perusteilla, ja ne sijaitsevat lajistollisesti arvokkailla alueilla. Lehtokasvien suojelualueverkon edustavuuden arvioinnissa tutkittiin toteutetun suojelun kattavuutta ja monipuolisuutta. Tulosten perusteella lehtojensuojeluohjelman kohteilla ja rauhoitetuilla lehdoilla on keskeinen osuus kasvilajistoltaan toisiaan hyvin täydentävien eli komplementaaristen kohteiden alueverkossa. Rauhoitetut lehdot ja etenkin lehtojensuojeluohjelman kohteet on valittu lajiston suhteen perustellusti. Toisaalta suojelulehtojen verkossa on myös puutteita. Etenkin kosteiden lehtojen ja lehtokorpien suojelualaa tulisikin kasvattaa. Noin 5 000 metsiemme eliölajia, joista 800 on lahopuukovakuoriaisia, on lahopuusta riippuvaisia. Elinkelpoisten lahopuukovakuoriaispopulaatioiden säilyttämistä tarkasteltiin ottamalla huomioon sekä metsäluonnon suojelualueverkko että talousmetsien avainbiotoopit ja uudistetut metsänkäsittelyohjeet. Lahopuun määrän ja lahopuukovakuoriaisten sekä muiden lahopuusta riippuvaisten eliöryhmien lajirunsauden välillä on selvä positiivinen korrelaatio. Lahopuun määrä Etelä-Suomen metsissä on vähentynyt 92 - 98 % luonnontilaiseen metsämaisemaan verrattuna. Ennusteiden mukaan tämä saattaa johtaa pitkällä aikavälillä lajimäärän puolittumiseen, joten yli 2 000 lahopuulajia on vaarassa kuolla sukupuuttoon maastamme. Lahopuun määrää tulisikin nopeasti kasvattaa sekä (olemassa olevien ja uusien) suojelualueiden metsien ennallistamistoimilla että lisäämällä lahopuuta talousmetsissä eli koko metsämaisemassa. Suojelualueverkon merkitystä havu- ja sekametsien lintulajistolle tarkasteltiin koko maan suojelualueverkossa tehtyjen lintulaskentojen perusteella. Tutkimuksessa tarkasteltiin 321ajia, jotka käsittivät useita uhanalaisia lajeja, taantuneita lajeja ja vanhoja metsiä suosivia lajeja. Tulosten perusteella nykyisen suojelualueverkkoon edustava vain niille lajeille, joiden levinneisyyden painopiste on pohjoisboreaalisella metsäkasvillisuusvyöhykkeellä. Sen sijaan suojelualueet eivät turvaa hemi-, etelä- tai keskiboreaaliselle vyöhykkeelle keskittynyttä lajistoa. Tulokset korostavat maan etelä- ja itäosien metsien suojelun merkitystä metsälintupopulaatioiden säilyttämiselle

Can Topographic Variation in Climate Buffer against Climate Change-Induced Population Declines in Northern Forest Birds?

Increased attention is being paid to the ecological drivers and conservation measures which could mitigate climate change-induced pressures for species survival, potentially helping populations to remain in their present-day locations longer. One important buffering mechanism against climate change may be provided by the heterogeneity in topography and consequent local climate conditions. However, the buffering capacity of this topoclimate has so far been insufficiently studied based on empirical survey data across multiple sites and species. Here, we studied whether the fine-grained air temperature variation of protected areas (PAs) affects the population changes of declining northern forest bird species. Importantly to our study, in PAs harmful land use, such as logging, is not allowed, enabling the detection of the effects of temperature buffering, even at relatively moderate levels of topographic variation. Our survey data from 129 PAs located in the boreal zone in Finland show that the density of northern forest species was higher in topographically heterogeneous PAs than in topographically more homogeneous PAs. Moreover, local temperature variation had a significant effect on the density change of northern forest birds from 1981–1999 to 2000–2017, indicating that change in bird density was generally smaller in PAs with higher topographic variation. Thus, we found a clear buffering effect stemming from the local temperature variation of PAs in the population trends of northern forest birds

Can Topographic Variation in Climate Buffer against Climate Change-Induced Population Declines in Northern Forest Birds?

Increased attention is being paid to the ecological drivers and conservation measures which could mitigate climate change-induced pressures for species survival, potentially helping populations to remain in their present-day locations longer. One important buffering mechanism against climate change may be provided by the heterogeneity in topography and consequent local climate conditions. However, the buffering capacity of this topoclimate has so far been insufficiently studied based on empirical survey data across multiple sites and species. Here, we studied whether the fine-grained air temperature variation of protected areas (PAs) affects the population changes of declining northern forest bird species. Importantly to our study, in PAs harmful land use, such as logging, is not allowed, enabling the detection of the effects of temperature buffering, even at relatively moderate levels of topographic variation. Our survey data from 129 PAs located in the boreal zone in Finland show that the density of northern forest species was higher in topographically heterogeneous PAs than in topographically more homogeneous PAs. Moreover, local temperature variation had a significant effect on the density change of northern forest birds from 1981–1999 to 2000–2017, indicating that change in bird density was generally smaller in PAs with higher topographic variation. Thus, we found a clear buffering effect stemming from the local temperature variation of PAs in the population trends of northern forest birds

Increasing protected area coverage mitigates climate-driven community changes

Climate change has ubiquitous impacts on ecosystems and threatens biodiversity globally. One of the most recognized impacts are redistributions of species, a process which can be hindered by habitat degradation. Protected areas (PAs) have been shown to be beneficial for preserving and reallocating species occurrences under climate change. Yet, studies investigating effects of PA networks on species' range shifts under climate change remain scarce. In theory, a well-connected network of PAs should promote population persistence under climate change and habitat degradation. To study this, we evaluated the effects of PA coverage on avian communities in Finland between two study periods of 1980-1999 and 2000-2015. Climate-driven community impacts were investigated by using community temperature index (CTI). We used linear models to study the association of PA coverage and the CTI changes in southern, central and northern Finland. In northern and central Finland, higher PA coverage was associated with lower changes in CTI and 45% PA coverage in northern and 13% in central Finland corresponded with complete mitigation of CTI increase. These results indicate that higher PA coverage strongly increases community resilience to warming climate. However a similar association between PA coverage and changes in CTI was not apparent in southern Finland. The PA coverage in southern Finland was much lower than in the two other sections and thus, may be too sparse to favour community resilience against climate change. The results provide empirical evidence for the international need to rapidly expand PA networks and halt biodiversity loss.Peer reviewe