Hybrid bioacoustic and ecoacoustic analyses provide new links between bird assemblages and habitat quality in a winter boreal forest

Resident birds in boreal forests can serve as indicators of habitat quality and are often species of conservation interest, particularly in multifunctional forests also used for timber production. To make informed forest management decisions, we must first understand which structural features provide habitats useful for resident birds. This is particularly true in winter, an understudied and critical season for their survival. The objective of this study was to establish reliable methods for monitoring bird presence and activity during winter, and to use these methods to evaluate the relative importance of stand structural features to make inferences about which features support and increase winter survival potential. Using a hybrid bioacoustic and ecoacoustic approach, we tested the ability of acoustic recordings to identify links between bird diversity and components of structural complexity, and compared these results to those from the traditional point count method. We conducted a vegetation survey, point count surveys and collected acoustic recordings from December 2019–February 2020 in 19 sites in a Swedish boreal forest. First, we compared species richness values derived from point counts and bioacoustic monitoring methods. Bioacoustic species richness was significantly higher than point count richness, although only when the time spent identifying species from recordings exceeded the time spent conducting point counts in the field. Next, we demonstrated that bioacoustic species identification yields additional metrics of bird activity that point counts cannot. We tested the response of these metrics, and point count metrics, to variables of structural heterogeneity and complexity of our sites. Almost all bioacoustic metrics increased significantly with increasing structural complexity, while point count richness and abundance did not, indicating that automated recording is more effective in identifying forest patches of high quality in winter. Lastly, using an ecoacoustic approach, we calculated six of the most common acoustic indices and tested if any could effectively reflect the bird-structure relationships described above. Two indices showed significant positive relationships to bioacoustic metrics, demonstrating their potential as biodiversity assessment proxies that respond to differences in habitat quality. This is the first winter acoustic study to monitor bird assemblages in detail; it employed both bioacoustic and multi-index ecoacoustic approaches, which provided evidence that automated acoustic recording can be an effective and superior method for monitoring resident forest birds

Effects of a coordinated farmland bird conservation project on farmers' intentions to implement nature conservation practices - Evidence from the Swedish Volunteer & Farmer Alliance

To increase the efficacy of agri-environmental schemes (AES), as well as farmers' environmental engagement, practitioners are increasingly turning to collective forms of agri-environmental manage- ment. As yet, empirical evidence from such approaches is relatively scarce. Here, we examined a farm- land bird conservation project coordinated by BirdLife Sweden, the Swedish Volunteer & Farmer Alliance (SVFA). The key features of the SVFA were farmland bird inventories from volunteering birdwatchers and on-farm visits to individual farmers from conservation advisors for guidance on AES as well as unsub- sidised practices. Using an ex-post application of the theory of planned behaviour across project par- ticipants and a randomly sampled control group of farmers we assessed how SVFA affected behavioural intentions relating to AES and unsubsidised conservation, and how the behaviour was affected by atti- tudes, perceived social norms and perceived behavioural control. We also included a measure of self- identity as a conservationist to assess its importance for behavioural intentions, and if SVFA stimu- lated this self-identity. SVFA farmers reported greater commitment to implementing AES and unsubsi- dised conservation, as compared to the control group. However, greater commitment was associated with more positive attitudes for unsubsidised conservation only and not for AES, underlining the inability of existing AES to prompt intrinsic motivation. There were also differences between farmers within SVFA, where farmers applying to the project were motivated by social influences, while farmers recruited by project managers were motivated by their personal beliefs regarding nature conservation. Finally, farmers' self-perceived ability to perform practices (i.e. perceived behavioural control) was important for their commitment to implementing AES as well as unsubsidised practices. Therefore, increasing farmers' awareness regarding the availability and, not least, practicability of available con- servation options may be the key to successful biodiversity conservation in agricultural systems

Samodla kornsorter - och minska bladlusangreppen

Samodling av specifika sortkombinationer mobiliserar kornets försvar mot bladlöss, vilket kan vara en viktig del av ett förebyggandeväxtskydd i ekologisk produktion. Men vilka sorter ska mansamodla? Ett pågående SLU- och Formasprojekt kommer ge svar

Do biodiversity-ecosystem functioning experiments inform stakeholders how to simultaneously conserve biodiversity and increase ecosystem service provisioning in grasslands?

Two key stakeholders primarily important for nature conservation are farmers (and their lobby groups) and conservationists. Both have substantial inputs into environmental strategies and policies calling for biodiversity conservation aimed to directly increase ecosystem services. The scientific literature concurs that as biological diversity increases so do ecosystem functions and services in grasslands. While the evidence for this is strong, the majority comes from controlled small-scale biodiversity-ecosystem functioning (BEF) experiments. Thus, it is unclear whether the scientific basis for implementing BEF relationships into practice is sufficiently evidenced. Here we explore the applicability of findings from BEF experiments to the conservation and management of temperate grassland, a widespread and potentially highly biodiverse habitat. While we acknowledge that BEF research can reveal insights into fundamental mechanisms, the saturation of biodiversity effects at low levels and unrealistic (management) treatments widely impede the applicability of these experimental results to permanent grasslands. Additionally, the integration of BEF research results into practice is considerably hampered by experimental studies not answering stakeholders' crucial questions, e.g. is there evidence of biodiversity conservation potentials? Thus, stakeholders do not have a strong evidence base for taking decisions for the addressed management goals, except intensive production in (species-poor) temporary grasslands. If BEF work is to inform stakeholders future research needs to overcome unrealistic management, missing stakeholder involvement and ineffective communication. A new generation of applied BEF experiments employing applied, multi-actor approaches is needed to facilitate the relevance of BEF research for nature conservation, agriculture and land management

Behaviour and life-history responses to chick provisioning under risk of nest predation

This thesis examines risk management in breeding Siberian jays (Perisoreus infaustus), which is indigenous to the northern taiga. Parent behaviour and the nest are cryptic. A new nest is built each year. It is placed on spruce or pine branches close to the trunk and well insulated with lichens, feathers and reindeer hair. Nest failure rate was the main factor driving annual variations in jay numbers. The probability for nesting attempts to be successful ranged annually between 0.08 and 0.70. Nest predation was rampant and a main cause of nest failure. Nest predators were mainly other corvids (primarily the Eurasian jay Garrulus glandarius). Habitat quality was the main factor determining the risk of predation. The risk for nest failure due to predation was higher in thinned forests with an open structure and with a high abundance of man-associated corvid species (jays, crows, raven). Siberian jay parents show several strategic adjustments in life-history and behaviour to the risk of nest predation. Parents traded reduced feeding rates for a lower predation risk and allocated feeding to low risk situations. Chick provisioning imposes a cost by drawing the attention of visually hunting predators to the location of nests, and parents adjusted their daily routines and avoided exposure by allocating provisioning to times of low activity among nest predators. These strategic adjustments of feeding efforts were estimated to reduce the exposure to nest predators by 26 percent. Also, parents adjusted their reproductive efforts to the perceived presence of predators in a playback experiment. Siberian jays reduced their reproductive investment by laying a smaller clutch size when high risk of nest predation reduced the value of current reproduction, as predicted from life-history theory

Foraging behavior of the Eurasian three-toed woodpecker (Picoides tridactylus) and its implications for ecological restoration and sustainable boreal forest management

Several studies have shown that the Three-toed Woodpecker (Picoides tridactylus) is strongly favored by large-scale disturbances, including forest fires. However, natural disturbances have largely disappeared from European boreal forests because of modern forestry practices and fire suppression. We currently lack knowledge on the foraging activity and resource use of the Eurasian Three-toed Woodpecker, especially in burned forests, and this restricts our ability to develop strategies for sustainable forest management and ecological restoration aiming at improving the situation of this woodpecker and associated species. In order to fill this knowledge gap, we studied the characteristics of selected foraging substrates and the foraging behavior of the Three-toed Woodpecker during the breeding season in unburned forests and forests that have been subjected to prescribed burning. We used instantaneous sampling duringtwo consecutive springs (2016-2017), where we observed the woodpeckers’ foraging behavior during a total of 977 minutes in burned forest and 962 minutes in unburned forests. The preferred foraging substrate for Three-toed Woodpeckers in both burned and unburned forests can be characterized as freshly dead trees with a DBH > 15 cm. However, data on time spent foraging on different substrates suggest that also substrates in the 5-15 DBH range and living trees are important. Additionally, prescribed burnings led to less pronounced selection of tree species, which suggest that fire may reduce differences in abundance of saproxylic insect prey between tree species. This information on substrate selection and foraging time provide complementary knowledge and thus should be used simultaneously when management strategies for improved woodpecker habitat are developed. Our results suggest that both prescribed burning and protecting forests with high density and diversity of dead wood provides habitat opportunities for Three-toed Woodpeckers and using both in management may maximize conservation outcom

Remotely sensed forest understory density and nest predator occurrence interact to predict suitable breeding habitat and the occurrence of a resident boreal bird species

Habitat suitability models (HSM) based on remotely sensed data are useful tools in conservation work. However, they typically use species occurrence data rather than robust demographic variables, and their predictive power is rarely evaluated. These shortcomings can result in misleading guidance for conservation. Here, we develop and evaluate a HSM based on correlates of long‐term breeding success of an open nest building boreal forest bird, the Siberian jay. In our study site in northern Sweden, nest failure of this permanent resident species is driven mainly by visually hunting corvids that are associated with human settlements. Parents rely on understory nesting cover as protection against these predators. Accordingly, our HSM includes a light detection and ranging (LiDAR) based metric of understory density around the nest and the distance of the nest to the closest human settlement to predict breeding success. It reveals that a high understory density 15–80 m around nests is associated with increased breeding success in territories close to settlements (<1.5 km). Farther away from human settlements breeding success is highest at nest sites with a more open understory providing a favorable warmer microclimate. We validated this HSM by comparing the predicted breeding success with landscape‐wide census data on Siberian jay occurrence. The correlation between breeding success and occurrence was strong up to 40 km around the study site. However, the HSM appears to overestimate breeding success in regions with a milder climate and therefore higher corvid numbers. Our findings suggest that maintaining patches of small diameter trees may provide a cost‐effective way to restore the breeding habitat for Siberian jays up to 1.5 km from human settlements. This distance is expected to increase in the warmer, southern, and coastal range of the Siberian jay where the presence of other corvids is to a lesser extent restricted to settlements

Tree species identity and composition shape the epiphytic lichen community of structurally simple boreal forests over vast areas

Greatly simplified ecosystems are often neglected for biodiversity studies. However, these simplified systems dominate in many regions of the world, and a lack of understanding of what shapes species occurrence in these systems can have consequences for biodiversity and ecosystem services at a massive scale. In Fennoscandia, ~90% of the boreal forest (~21Mha) is structurally simplified with little knowledge of how forest structural elements shape the occurrence and diversity of for example epiphytic lichens in these managed forests. One form of structural simplification is the reduction of the number and frequency of different tree species. As many lichen species have host tree preferences, it is particularly likely that this simplification has a huge effect on the lichen community in managed forests. In a 40–70 years old boreal forest in Sweden, we therefore related the occurrence and richness of all observed epiphytic lichens to the host tree species and beta and gamma lichen diversity at the forest stand level to the stand’s tree species composition and stem diameter. Picea abies hosted the highest lichen richness followed by Pinus sylvestris, Quercus robur, Alnus glutinosa, Betula spp., and Populus tremula. However, P. tremula hosted twice as many uncommon species as any of the other tree species. Stand level beta and gamma diversity was twice as high on stands with four compared to one tree species, and was highest when either coniferous or deciduous trees made up 40–50% of the trees. The stem diameter was positively related to lichen richness at the tree and stand level, but negatively to beta diversity. For biodiversity, these findings imply that leaving a few trees of a different species during forest thinning is unlikely as effective as combining life-boat trees for endangered species with an even tree species mixture

What is good for birds is not always good for lichens: Interactions between forest structure and species richness in managed boreal forests

Forestry in the boreal region increasingly replaces natural disturbances in shaping biodiversity. Large-scale removal of small diameter trees (thinning), is ubiquitous in northern European forestry, yet an understanding of how it relates to biodiversity across taxa is lacking. To address this, we examined how two forest structural elements, commonly impacted by forest thinning (i.e. vegetation density in the understory and overstory), are correlated with the species richness of forest-dwelling birds and epiphytic lichens. These taxa were chosen because they likely have opposing habitat demands: epiphytic lichens potentially benefitting from more light in open forests, and birds benefitting from structurally complex forests for foraging, nesting and cover. We used remote sensing tools, already applied in forestry planning, to see if management recommendations could be found that balance the needs of both taxonomic groups within the same forests. Our results show that richness in epiphytic lichens and forest-dwelling birds is not correlated and that a high species richness (similar to 15 birds &amp; similar to 40 epiphytic lichens) in both taxa is only predicted in the same stand under a specific vertical distribution and density of the forest's vegetation: this occurs when the vegetation above 3 m is open (to promote epiphytic lichen richness) and below 3 m is dense (to promote bird richness). Dense vegetation up to 7 m above ground has a diverging effect on forest birds (positive) and epiphytic lichens (negative). A larger stem diameter further increases species richness in both taxa. Our study provides results that are directly implementable in forestry planning over large areas with the help of remote sensing tools (LiDAR)