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375 results for “Boreal forests”
Modelling Avian Habitat Suitability in Boreal Forest using Structural and Spectral Remote Sensing Data
<p>Data used in research regarding avian habitat suitability models in Harry's River Watershed in Newfoundland, Canada</p>
Data from: Prey availability and ambient temperature influence carrion persistence in the boreal forest
<p>1. Scavenging by vertebrates can have important impacts on food web stability and persistence, and can alter the distribution of nutrients throughout the landscape. However, scavenging communities have been understudied in most regions around the globe, and we lack understanding of the biotic drivers of vertebrate scavenging dynamics.</p> <p>2. In this paper, we examined how changes in prey density and carrion biomass caused by population cycles of a primary prey species, the snowshoe hare (<i>Lepus americanus</i>), influence scavenging communities in the northern boreal forest. We further examined the impact of habitat and temperature on scavenging dynamics.</p> <p>3. We monitored the persistence time, time until first scavenger, and number of species scavenging experimentally-placed hare carcasses over four consecutive years in the southwestern Yukon. We simultaneously monitored hare density and carrion biomass to examine their influence relative to temperature, habitat, and seasonal effects. For the primary scavengers, we developed species-specific scavenging models to determine variation on the effects of these factors across species, and determine which species may be driving temporal patterns in the entire community.</p> <p>4. We found that the efficiency of the scavenging community was affected by hare density, with carcass persistence decreasing when snowshoe hare densities declined, mainly due to increased scavenging rates by Canada lynx (<i>Lynx canadensis</i>). However, prey density did not influence the number of species scavenging a given carcass, suggesting prey abundance affects carrion recycling but not necessarily the number of connections in the food web. In addition, scavenging rates increased in warmer temperatures, and there were strong seasonal effects on the richness of the vertebrate scavenging community.</p> <p>5. Our results demonstrate that vertebrate scavenging communities are sensitive to changes in species' demography and environmental change, and that future assessments of food web dynamics should consider links established through scavenging.</p>
Data from: Climate change increases predation risk for a keystone species of the boreal forest
<p>Canada lynx (<i>Lynx canadensis</i>) and snowshoe hares (<i>Lepus americanus</i>) form a keystone predator-prey cycle that has large impacts on the North-American boreal forest vertebrate community. Snowshoe hares and lynx are both well-suited for snowy winters, but climate change associated shifts in snow conditions could lower hare survival and alter cyclic dynamics. Using detailed monitoring of snowshoe hare cause-specific mortality, behaviour, and prevailing weather, we demonstrate that hare mortality risk is strongly influenced by variation in snow conditions. Although predation risk from lynx was largely unaffected by snow conditions, coyote (<i>Canis latrans</i>) predation increased in shallow snow. Maximum snow depth in our study area has decreased 33% over the last two decades and predictions based on prolonged shallow snow indicate future hare survival could resemble that seen during population declines. Our results indicate that climate change could disrupt cyclic dynamics in the boreal forest.</p>
Effects of different moose browsing pressures on the succession of plant communities within the herbaceous and saplings layers of a boreal forest
<p>The present data is constituted of four different excel files: browsing data, herbs layer data, saplings layer data and latin names data.</p> <p>1) Browsing data contains the number of browsed and unbrowsed twigs from all ligneous plants in the samplings plots along time.</p> <p>2) Herbs layer data contains the cumulated cover of all plants species along 14 three meters long and one meter high transcects within each experimental units.</p> <p>3) Saplings layer data contains the number of saplings from each species within each experimental units (280 m2).</p> <p>4) Latin names data contains the latin names corresponding to the different species codes found within the herbs and saplings data.</p> <p>All data sets contain his metadata sheet.</p>
Data set: Burn severity and soil chemistry are weak drivers of early vegetation succession following a boreal mega-fire in a production forest landscape
<p>Data used in the analyses of the study. Data set on soil chemistry (pH, organic content, nutrient content), plots distance to the fire perimeter, and plant communities (vascular plants and bryophytes) recorded in permanent plots on clearcuts in a burn-severity gradient two and five years following a wildfire. Data collected from a 13000 hectare wildfire that occurred in 2014, in boreal southern Sweden. Calculated trait means from data bases, and plant community data from unburned plots from another study, are are also included here.</p>
Macroclimate drives growth of hair lichens in boreal forest canopies
<p><b>1. </b>Epiphytic lichens are important biodiversity components of forest canopies worldwide, significantly contributing to ecosystem function. The relative growth rate (RGR), a measure of fitness, drives population dynamics and shapes lichens' large-scale distributions. In a climate change scenario, we need to know how external (macro- and microclimate, and nitrogen deposition), and internal factors (cortical pigments, chlorophyll and specimen size) affect RGR in these ecologically important canopy organisms.</p> <p><b>2. </b>We used dominant pendulous (hair) lichens widely distributed across the boreal biome to test the hypothesis that precipitation drives RGR of pale (<i>Alectoria sarmentosa,</i> <i>Usnea dasopoga</i>) and dark species (<i>Bryoria fuscescens</i>) to a different extent across a large-scale gradient from continental to oceanic climates (precipitation: 450-2600 mm) in Scandinavia (60-64° N, 5-19° E). After transplanting lichens to lower branches of <i>Picea abies</i> in nine boreal forest sites for one year, we used linear mixed effect models to analyze how total precipitation, rainfall, number of days with rain, temperature sum, nitrogen deposition, light, chlorophyll <i>a</i> (an indicator of photosynthetic capacity), and size influenced their RGR.</p> <p><b>3. </b>RGR was highest in the pale species (<i>Alectoria</i> and <i>Usnea</i>) and increased with amount and frequency of precipitation, with >3 times higher RGR in the wettest compared to the driest site. The number of days with rain was a better predictor of RGR than total precipitation or rain. By contrast, RGR of the dark <i>Bryoria</i> weakly increased with precipitation. RGR in all species increased with light and decreased with size. Chlorophyll <i>a</i> concentration, boosted by moderate nitrogen deposition, increased RGR of all species.</p> <p><b>4. </b>In conclusion, rainfall likely drives the distribution of the pale species due to their higher RGR and abundance in wet climates but cannot explain why <i>Bryoria</i> dominate drier inland forests. Our results highlight that the functional links between rainfall and RGR depends on both color of the lichens (pale versus dark pigments) and hydration traits.</p> <p><b>5.</b><i> Synthesis</i>. Our findings may explain the global, regional and local distribution patterns of hair lichens and help us to predict how environmental hazards such as climate change and forestry influence these important boreal canopy components.</p>
Permafrost thaw in boreal peatlands is rapidly altering forest community composition
<p>Boreal peatlands are frequently underlain by permafrost, which is thawing rapidly. A common ecological response to thaw is the conversion of raised forested plateaus to treeless wetlands, but unexplained spatial variation in responses, combined with a lack of stand-level data, make it difficult to predict future trajectories of boreal forest composition and structure. We sought to characterize patterns and identify drivers of forest structure, composition, mortality, and recruitment in a boreal peatland experiencing permafrost thaw. To do this, we established a large (10 ha) permanent forest plot (completed in 2014), located in the Northwest Territories, Canada, that includes 40,584 mapped and measured trees. In 2018, we conducted a comprehensive mortality and recruitment recensus. We also measured frost table depth, soil moisture, soil humification, and organic layer thickness within the plot between 2012 and 2018, and used habitat association tests to link these variables to forest characteristics and dynamics. Forest composition and structure varied markedly throughout the plot and were strongly governed by patterns in permafrost presence and organic layer thickness. Overall, there was a net loss of trees from the plot at a rate of 0.7% yr-1. Mortality of black spruce, the dominant tree species, was more than double that of recruitment and was strongly associated with permafrost thaw. In contrast, recruitment of larch was over four times greater than mortality, and occurred primarily in low-lying, permafrost-free wetlands with mineral soil near the surface. The trends in tree demography and underlying drivers suggest that spruce-dominated permafrost plateaus will be converted into larch-dominated wetlands as permafrost thaw progresses in boreal peatlands, particularly in areas where mineral soil is near the surface. In the longer term, thaw could increase the hydrologic connectivity of the landscape, resulting in widespread drainage and re-vegetation by spruce, but we did not find evidence that this is occurring yet. Given the increasing rates of permafrost thaw, and positive feedbacks between thaw and forest change, we predict that larch abundance will continue to increase in boreal peatlands over the coming decades, leading to shifts in ecosystem function, wildlife habitat, albedo, and snow dynamics.</p>
Data from: Variations in ratio and loads of soil nitrogen and phosphorus explain the coexistence of dominant tree species in a boreal forest of Xinjiang, northwest China
<p><span>The resource ratio hypothesis (RRH) and the nutrient-load hypothesis (NLH) state that species coexistence is driven by the ratios and loads (contents) of multiple limiting resources, respectively. However, roles of resource ratios and loads to mature forest ecosystems remains unclear. Data were collected within 300 quadrats (20m×20m) spread across a 12 ha plot of boreal forest in the Kanas of Xinjiang, northwest China. We used torus translation tests to analyze the associations of dominant tree species with specific microhabitats. The linear mixed models were used to assess effects of resource ratios and contents on abundance and basal area of specific species, as well as within different life stages. Two shade-tolerant species, <i>Picea obovata</i> and <i>Pinus sibirica</i>, exhibited opposite relationships to the spatial distribution of soil nitrogen (N) content and phosphorus (P) content. <i>Picea. obovata</i> was associated with microhabitats with high N:P ratio, while <i>P. sibirica</i> preferred microhabitats with low N:P ratio. The light-demanding trees, <i>Betula pendula</i> clustered at both low N and P sites. Another light-demanding trees, <i>Larix sibirica</i>, did not show any significant habitat preferences. Moreover, N:P ratio mainly affected species abundance, while their contents largely impacted basal area of species. And effects of N:P ratio or contents on species distribution showed a decreasing trend from sapling to adults. Overall, our findings indicate that niche partitioning caused by resource variations may alleviate interspecific competition and contribute to the species coexistence, providing convincing proof for the importance of resource ratio and load on maintaining diversity in boreal forests. </span></p>
Remotely sensed forest understory density and nest predator occurrence interact to predict suitable breeding habitat and the occurrence of a resident boreal bird species
<p>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 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 favourable 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.</p>
Projected effects of climate change on boreal bird community accentuated by anthropogenic disturbances in western boreal forest, Canada
<p><b>Aim</b></p> <p>Climate change<b> </b>is expected to influence boreal bird communities significantly, notably through changes in forest habitat (composition and age structure),<b> </b>in the coming decades. How these changes will accumulate and interact with anthropogenic disturbances remains an open question for most species.</p> <p><b>Location</b></p> <p>Northeastern Alberta, Canada.</p> <p><b>Methods </b></p> <p>We used the LANDIS-II forest landscape model to project changes in forest landscapes, and associated bird populations (72 passerine species), according to three climatic scenarios (baseline, RCP 4.5, RCP 8.5) and three forest harvesting scenarios of differing intensity.</p> <p><b>Results</b></p> <p>Both forest harvesting and climate-related drivers were projected to have large impacts on bird communities in this region. As a result of climate-induced increases in fire activity as well as decreased conifer productivity, our simulations projected that an important proportion of Alberta's boreal forests would transition to treeless habitat (i.e. grass-, or shrub-dominated vegetation) while many conifer-dominated stands would likely be replaced by broadleaf tree cover. Consequently, the abundance of bird species associated with open and deciduous habitats were projected to increase. With a strong anthropogenic climate forcing scenario (RCP 8.5), sharp declines in abundance of coniferous trees were also projected, particularly in mature and old forest stands, triggering major declines for bird species associated with coniferous and mixedwood forest types.</p> <p><b>Main Conclusions</b></p> <p><a>As the most comprehensive simulation of climate change and harvesting impacts on avian habitats in the North American boreal region to date</a>, our study <a>reveals</a> the importance of considering key habitat characteristics like forest age structure and composition through forest landscape modeling, and identifies 18 bird species particularly sensitive to climate change. Our simulations suggest that a change in forest management practices could play an important role in the conservation of boreal bird species vulnerable to climate change. The intensive forest harvesting simulated accelerated declines in bird abundance compared to a "no harvesting" scenario.</p> <div> <div> <div class="msocomtxt"> </div> </div> </div>
Occupancy and detection probability of American Three-toed Woodpecker in a heavily-managed boreal forest of eastern Canada
<p>The southern extent of the boreal forest in North America has experienced intensive human disturbance in recent decades. Among these, forest harvesting leads to the substantial loss of late-successional stands that include key habitat attributes for several avian species. The American Three-toed Woodpecker, <em>Picoides dorsalis</em>, is associated with continuous old spruce forests in the eastern part of its range. In this study, we assessed the influence of habitat characteristics at different scales on the occupancy of American Three-toed Woodpecker in a heavily-managed boreal landscape of northeastern Canada, and we inferred species occupancy at the regional scale. We conducted 185<br> playback stations over two breeding seasons and modelled the occupancy of the species while taking into account the probability of detection. American Three-toed Woodpecker occupancy was lower in stands with large areas recently clear-cut, and higher in landscapes with large extents of old-growth forest dominated by black spruce. At the regional scale, areas with high probability of occupancy were scarce and mostly within protected areas. Habitat requirements of the American Three-toed Woodpecker during the breeding season, coupled with overall low occupancy rate in our study area, challenge its long-term sustainability in such heavily managed landscapes. Additionally, the scarcity of areas of high probability of occupancy in the region suggests that the ecological role of old forest outside protected areas could be compromised.</p>
Data from: Can novel pest outbreaks drive ecosystem transitions in northern-boreal birch forest?
1. The boreal biome exhibits distinct alternative ecosystem states with high and low levels of tree-cover. Insect outbreaks facilitated by climate warming could potentially drive transitions from high to low tree-cover states. We investigated whether two key premises for such outbreak-induced transitions – critical thresholds (tipping points) and positive feedbacks that could maintain alternative states – are present in the northern-boreal mountain birch forest of Fennoscandia. Here, climate warming has promoted range expansions of defoliating geometrid moths, resulting in novel, severe multispecies outbreaks, most recently during 2002-2010. 2. We conducted regional-scale field surveys of forest damage and recovery in 280 mountain birch stands in a northeast Norway immediately after the outbreak (2010) and six years later (2016). Satellite-derived time series of the normalized difference vegetation index (NDVI) provided an index of stand defoliation during the outbreak period. 3. The proportion of dead stems per stand displayed a bimodal distribution, with stands generally being either lightly or severely damaged. This was due to a critical threshold in the relationship between defoliation and stem mortality, with mortality rates increasing abruptly in stands experiencing a mean drop in NDVI of more than 4 % during the outbreak. The two key forest regenerative pathways – basal sprouting and sapling production – both displayed positive feedbacks with surviving stems and trees, so that regeneration success declined with increasing damage to the mature tree layer. These feedbacks imply that stands which have been forced across critical defoliation thresholds and suffered collapses of living tree cover may struggle to recover, especially if the loss of positive regenerative feedbacks is compounded by ungulate browsing on birch recruits. 4. Synthesis. The north Fennoscandian mountain birch forest displays critical thresholds and positive feedbacks that conform to theoretical expectations for a system that could be vulnerable to abrupt and persistent changes of state in the face of novel, climatically facilitated insect outbreaks. These findings deepen the understanding of the persistent losses of tree-cover that have occasionally been observed after outbreaks in this system in the past, and adds to the list of mechanisms that could help explain the bistability of tree-cover across the boreal biome.
Data from: Exploiting Poisson additivity to predict fire frequency from maps of fire weather and land cover in boreal forests of Québec, Canada
Predictive models of fire frequency conditional on weather and land cover are essential to assess how future cover-type distributions and weather conditions may influence fire regimes. We modelled the effects of bottom-up variables (e.g. land cover) and top-down variables (e.g. fire weather) simultaneously with data aggregated or interpolated to spatial and temporal units of 100 km2 and 1yr in the boreal forest of Québec, Canada. For models of human-caused fires, we used road density as a surrogate for human access and behaviour. We exploited the additive property of Poisson distributions to estimate cover-type specific fire count rates, which would normally not be possible with data of this spatial resolution. We used piecewise linear functions to model nonlinear relations between fire weather and fire frequency for each cover-type simultaneously. The estimated conditional rates may be considered as expected mean counts per unit area and time. It follows that these rates can be rescaled to arbitrary spatial and temporal extents. Our results showed fire frequency increased nonlinearly as aridity increased and more quickly in disturbed areas than other types. Road density exerted the strongest influence on the frequency of human-caused fires, which were positively correlated with road density. The estimates may be used to parameterize the fire ignition component of spatial simulation models, which often have a resolution different from that at which the data were collected. This is an essential step in incorporating biotic and abiotic feedbacks, land-cover dynamics, and climate projections into ecological forecasting. The insight into the power of Poisson additivity to reveal high-resolution ecological processes from low-resolution data could have applications in other areas of ecology.
Data from: Ten-year responses of ground-dwelling spiders to retention harvest in the boreal forest
The Ecosystem Management Emulating Natural Disturbances (EMEND) project tests the hypothesis that varying levels of green tree retention maintain and retain forest biodiversity better than conventional clear-cutting. We studied epigaeic spiders to assess biodiversity changes two, five and ten years following a range of partial retention harvests (clear-cut, 10-75% retention) and unharvested controls in four boreal mixedwood cover-types. A total of 56, 371 adult spiders representing 220 species was collected using pitfall traps. Lasting effects on forest structure were proportional to harvest intensity. These changes strongly influenced spider richness, abundance and species composition, as well as assemblage recovery. Distinctive assemblages were associated with disturbance level, especially with partial harvests (≤50% retention), and these were dominated by open-habitat species even ten years after harvest. Assemblages were more similar to those of controls in the highest (75%) retention treatment, but significant recovery toward the structure of pre-disturbance assemblages was not detected for any prescription in any cover-type. Although early responses to retention harvest suggested positive effects on spider assemblages, these are better explained as lag effects after harvest because assemblages were less similar to those of unharvested controls five years post-harvest, and only minor recovery was observed ten years following harvest. Retention of forest biodiversity decreased over time, especially in conifer stands and the lower (10-50%) retention treatments. Overall, retention harvests retained biodiversity and promoted landscape heterogeneity somewhat better than clear-cutting; however, there was a clear gradient of response and no retention 'threshold' for conservation can be recommended on the basis of our data. Furthermore, results suggest that retention harvest prescriptions should be adjusted for cover-type. We show that low retention ameliorated impacts in broadleaved forests characteristic of earlier stages in mixedwood succession, but only higher retention was associated with less impact in successionally older conifer forests. Although these short-term responses (10 years) of spider assemblages support use of retention harvests, understanding the true conservation merit of these practices, relative to conventional approaches, requires evaluation over longer time scales, with work more focused on recovery of biodiversity than on its preservation after harvest.
Data from: Effects of species diversity on fine root productivity increase with stand development and associated mechanisms in a boreal forest
There is a growing interest in understanding the relationship between diversity and below-ground productivity due to the critical contribution of below-ground systems to overall terrestrial productivity. Yet, the temporal (seasonal and developmental) changes in diversity effects on below-ground productivity and their underlying mechanisms remain unclear. We hypothesized that (i) diversity effects on fine root productivity increase with stand development, and (ii) increased diversity effects associated with stand development result from augmented horizontal soil space utilization, increased forest floor depth for rooting, enhanced effects in nutrient-poor soil layers and/or foraging towards high nutrient availability. We investigated the effects of tree species diversity on fine root productivity by sampling 18 stands dominated by single species and their mixtures in post-fire boreal forests of two stand ages (8 and 34 years following stand-replacing fire). Species evenness was significantly higher in species mixtures than in single-species-dominated stands at both age classes, while species richness did not differ across stand types and age classes. We found that the annual fine root production was higher in mixtures than the mean of single-species-dominated stands in both stand ages, with a significantly higher magnitude of effects in the 34-year-old than 8-year-old stands. Mixtures had higher horizontal soil volume filling than single-species-dominated stands with a more pronounced increase in the 34-year-old than 8-year-old stands. Compared with the 8-year-old stands, the 34-year-old stands had increased forest floor depth and greater overyielding with soil depth, and their fine root productivity was more responsive to the vertical variation in soil phosphorus concentrations among soil layers. Synthesis. Our results provide evidence for increasing positive diversity effects on fine root productivity with stand development in heterogeneous natural forests. Moreover, our results indicate that the increased positive diversity effects with stand development was the result of multiple mechanisms, including higher horizontal soil volume filling, a thicker forest floor layer for rooting, a higher magnitude of complementarity in nutrient-poor deep soil layers and stronger nutrient foraging towards soil layers with high nutrient concentrations in older than younger stands.
Data from: Trade-offs in the multi-use potential of managed boreal forests
1. Implementing multi-use forest management to account for both commercial and non-commercial ecosystem services is gaining increased global recognition. Despite its spatial extent, and great economic and ecological values, few studies have evaluated the boreal forest and its management to assess the potential for simultaneous delivery of a suite of ecosystem services. 2. Using data from a Swedish long-term experiment this study explores how biodiversity of the ground vegetation and potential delivery of multiple ecosystem services (timber production, carbon (C) storage and non-timber forest products) are influenced by two common silvicultural practices (thinning, fertilization and their interaction). 3. Diversity (diversity indices and species richness) of the ground vegetation was higher in thinned than in unthinned forest, something partly explained by six species of lichens that only occurred in thinned forest. In addition, supply of lichens for reindeer forage was three times higher in thinned forest. Fertilization negatively affected the lingonberry shrub (Vaccinium vitis-idaea). Timber production increased with fertilization, but decreased with thinning. The potential for C storage was highest in fertilized forests, which, apart from having the highest timber production, also supported the highest standing tree biomass. 4. The silvicultural practices evaluated induced trade-offs among the ecosystem features studied as thinning increased biodiversity of the ground vegetation, production potential of wild berries and lichens, but reduced timber production and the forest's potential for C storage. Fertilization, had the opposite effect, promoting the potential for C storage at the expense of biodiversity and the ecosystem services delivered by the ground vegetation. 5. Synthesis and applications. Silvicultural practice had a pronounced effect on the multi-use output, and trade-offs among values were common. Nevertheless, our study demonstrates that silvicultural practices that are currently adopted in Sweden can be used to adjust the multi-use potential output of forests, suggesting that commonly used practices can be applied to maintain, or even increase the multi-use potential of the boreal forest biome, if management objectives are allowed to vary across the landscape. A prerequisite for this is site specific management objectives that clearly determine the desired output.
Data from: Depth-to-water mediates bryophyte response to harvesting in boreal forests
1. Site moisture is an important component of the forest landscape for maintaining biodiversity, including forest-floor bryophytes, but little is known about its role in shaping understory responses to harvesting. 2. We investigated the influence of site wetness, determined using a remotely-sensed, topographic depth-to-water (DTW) index, on responses of bryophyte cover, richness, diversity, and composition to variable retention harvesting (comparing: 2% [clear-cut], 20%, and 50% dispersed green tree retention and uncut controls [100% retention]) in three boreal forest cover-types (broadleaf, mixed, and conifer forests) in western Canada. The DTW index provides an approximation of depth to water at or below the soil surface, and was derived from wet-areas mapping based on discrete Airborne Laser Scanning data acquired over an experimentally harvested landscape located in northwestern Alberta, Canada. 3. The effectiveness of leaving retention (versus clear-cutting) for conserving bryophyte communities depended on site wetness, as indicated by DTW, with the specifics varying among forest types. In broadleaf forests, bryophyte cover and richness were generally low and not much affected by harvesting but drier sites had higher richness and a few more unique species. In mixed and conifer forests, leaving retention (versus clear-cutting) on wetter (versus drier) sites was more effective for conserving bryophyte cover, wetter sites had higher total species richness, and more species were exclusive to wetter sites. 4. Synthesis and applications. Site wetness, as indicated using the remotely-sensed topographic site wetness index "depth-to-water," mediates bryophyte responses to variable-retention harvests. Specifically, our results suggested that in conifer and mixed forests it would be more beneficial to target wetter sites for retention patches or dispersed retention whereas in broadleaf sites there might be a slight advantage to targeting drier sites. Our study demonstrates that this tool could be used to inform management decisions around leaving dispersed or patch retention.28-Jan-2019
Data from: Effects of undergrowth removal and edge proximity on ground beetles and vascular plants in urban boreal forests
Urban forests are regularly managed for human safety and aesthetic reasons, but they are crucial habitat for many species. Removals of undergrowth occur commonly in these forests, yet the ecological consequences of these operations are poorly understood. We sampled ground beetles (Coleoptera, Carabidae) and vascular plants along 20-m edge gradients in Finnish urban forests, in five stands treated 0.5−2.5 years earlier with undergrowth removal and in five untreated stands. We hypothesized that undergrowth removal and edge proximity would benefit opportunistic and open-habitat species, whereas shady-habitat species would be affected negatively. (1) Regarding carabids, diversity and evenness indices, open-habitat species and Carabus nemoralis responded positively, and forest species, Leistus terminatus and Pterostichus oblongopunctatus responded negatively, to the undergrowth removal. Regarding plants, generalists, Maianthemum bifolium, Rubus saxatilis and Sorbus aucuparia responded positively, and forest species, Geranium sylvaticum, Oxalis acetocella and Vaccinium myrtillus responded negatively, to the undergrowth removal. (2) Edge proximity had little effect on both plants and carabids. However, open-habitat carabids were less abundant and less speciose, and the plants Oxalis acetocella, Trientalis europaea and Rubus saxatilis had higher cover, 10−20 m from than right at the edge. (3) Plant (but not carabid) community responded to the undergrowth removal but not to the edge proximity. While managing urban forests, we recommend an avoidance of undergrowth removals at sites that host rare or threatened forest-associated flora and fauna.
Data from: Short-term climate change manipulation effects do not scale up to long-term legacies: effects of an absent snow cover on boreal forest plants
1. Despite time lags and non-linearity in ecological processes, the majority of our knowledge about ecosystem responses to long-term changes in climate originates from relatively short-term experiments. 2. We utilized the longest ongoing snow removal experiment in the world and an additional set of new plots at the same location in northern Sweden to simultaneously measure the effects of long-term (11 winters) and short-term (1 winter) absence of snow cover on boreal forest understorey plants, including effects on root growth and phenology. 3. Short-term absence of snow reduced vascular plant cover in the understorey by 42%, reduced fine root biomass by 16%, reduced shoot growth by up to 53%, and induced tissue damage on two common dwarf shrubs. In the long-term manipulation, more substantial effects on understorey plant cover (92% reduced) and standing fine root biomass (39% reduced) were observed, whereas other response parameters, such as tissue damage, were observed less. Fine root growth was generally reduced, and its initiation delayed by c. 3 (short-term) to 6 weeks (long-term manipulation). 4. Synthesis We show that one extreme winter with a reduced snow cover can already induce ecologically significant alterations. We also show that long-term changes were smaller than suggested by an extrapolation of short-term manipulation results (using a constant proportional decline). In addition, some of those negative responses, such as frost damage and shoot growth, were even absolutely stronger in the short-term compared to the long-term manipulation. This suggests adaptation or survival of only those individuals that are able to cope with these extreme winter conditions, and that the short-term manipulation alone would over-predict long-term impacts. These results highlight both the ecological importance of snow cover in this boreal forest, and the value of combining short- and long-term experiments side by side in climate change research.
Data from: Host phenology and potential saprotrophism of ectomycorrhizal fungi in the boreal forest
Phenology-induced changes in carbon assimilation by trees may affect carbon stored in fine roots and as a consequence, alter carbon allocated to ectomycorrhizal fungi. Two competing models exist to explain carbon mobilization by ectomycorrhizal fungi. Under the 'saprotrophy model', decreased allocation of carbon may induce saprotrophic behaviour in ectomycorrhizal fungi, resulting in the decomposition of organic matter to mobilize carbon. Alternatively, under the 'nutrient acquisition model', decomposition may instead be driven by the acquisition of nutrients locked within soil organic matter compounds, with carbon mobilization a secondary process. We tested whether phenology-induced shifts in carbon reserves of fine roots of aspen (Populus tremuloides) affect potential activity of four carbon-compound degrading enzymes, β-glucuronidase, β-glucosidase, N-acetylglucosaminidase and laccase, by ectomycorrhizal fungi. Ectomycorrhizal roots from mature aspen were collected across eight stands in north-eastern Alberta, Canada, and analysed during tree dormancy, leaf flush, full leaf expansion and leaf abscission. We predicted potential extracellular enzyme activity to be highest when root carbon reserves were lowest, should host phenology induce saprotrophism. Further, we anticipated enzyme activity to be mediated by invertase, a plant-derived enzyme which makes carbon available to fungal symbionts in the plant–fungus interface. Root carbon reserves were positively correlated with invertase, suggesting phenology may affect carbon allocation to ectomycorrhizal fungi. However, of the four enzymes, host phenology had the largest effect on β-glucuronidase, but activity of this enzyme was not correlated with root carbon reserves or invertase. Low-biomass ectomycorrhizas had greater potential laccase activity than high-biomass ectomycorrhizas, highlighting discrete functional traits in fungi for litter decomposition. Our results suggest that the decomposition of organic matter may be driven by foraging by fungi for nutrients locked within organic compounds rather than for mobilizing carbon. Furthermore, the potential ability to degrade lignin was more common in low-biomass ectomycorrhizas when compared to high-biomass ectomycorrhizas.
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Allen Brain Atlas
Allen Brain Atlas is an Allen Institute collection of brain map atlases, datasets, APIs, and analysis tools covering mouse, human, and non-human primate brain resources.
Annotated Behaviour and Observability Dataset (ABODe)
ABODe is a University of Edinburgh DataShare dataset for behavior classification in group-housed mice using home-cage video, identities, bounding boxes, ground-plate positions, and annotator labels.
DANDI Archive for NWB datasets
DANDI is a BRAIN Initiative archive for publishing and sharing neurophysiology data, including electrophysiology, optophysiology, and behavioral data packaged as NWB and related standards.
International Brain Laboratory public data
The International Brain Laboratory public data releases expose standardized mouse decision-making experiments, including Neuropixels recordings, widefield calcium imaging, behavior, and session metadata accessed through the ONE API.
OpenNeuro
OpenNeuro is a free, open platform for sharing neuroimaging datasets, with public search, dataset pages, and download paths for web, S3, DataLad, and the OpenNeuro CLI.