Boreal Habitats Research Articles

Temporal changes in boreal vegetation under 70 years of conservation

Biodiversity conservation through protected areas (PAs) is often based on the idea that biodiversity is relatively static. This assumption is increasingly being challenged as species and communities shift their distributions in response to changing environmental conditions. Empirical evidence on the performance of PAs over decades is still sparse or lacking from several environments, although it is needed to understand species dynamics, support modelling of PA performance, assist PA management and ultimately, to achieve global biodiversity conservation goals. In 2021, we resurveyed vegetation of five boreal habitat types (heath forests, paludified forests, sun-exposed sites, mires and eulittoral sites) in Rokua National Park in Finland, where one of the conservation targets is to preserve the flora characteristic of the area. The study sites were originally surveyed in 1945-49, just before the National Park was established. Study sites have also remained free from the disturbances (forest fires and reindeer grazing) typical of boreal regions. We show that the compositional similarity of plant communities between habitat types has increased over time and is associated with the increase of forest species in several habitat types and the loss of many habitat-specific species. Drivers of change were most often linked to ongoing succession (understory closure) and changes in moisture conditions. Our results suggest that without natural disturbance or appropriate management efforts, the original conservation targets may be compromised over the decades. Our study demonstrates that resurvey of historical vegetation data can be effectively used to estimate long-term PA performance, helping to fill in missing temporal evidence.

Mycorrhizal ecology would benefit from region-specific hypotheses

Most arbuscular mycorrhizal fungi exhibit global distributions but have been studied mostly in a specific region of the globe, mainly covering temperate and boreal habitats, where nitrogen is the most common nutrient limiting primary productivity. Yet, it is relatively common to extrapolate our understanding of temperate and boreal systems to other regions of the globe. While the physiology of mycorrhizal associations is unlikely to differ worldwide, there are good chances that environmental settings interact with the way mycorrhizas function across ecoregions. Here, we first argue that mycorrhizal ecologists should develop region-specific hypotheses. We subsequently identify likely differences in how mycorrhizas function in subtropical regions compared with better-studied temperate and boreal areas. We finally use the subtropical region of China to develop five geographically-focused hypotheses, envisaging that they will trigger the interest of the scientific community worldwide in understudied regions into studying mycorrhizas through a new lens. Expanding the range of hypotheses in mycorrhizal ecology to describe understudied regions of the world, has the potential to confer multifaceted benefits to both science and society. We advocate to do so, and present a roadmap on how to develop such hypotheses.

Predicting moose behaviors from tri-axial accelerometer data using a supervised classification algorithm

BackgroundMonitoring the behavior of wild animals in situ can improve our understanding of how their behavior is related to their habitat and affected by disturbances and changes in their environment. Moose (Alces alces) are keystone species in their boreal habitats, where they are facing environmental changes and disturbances from human activities. How these potential stressors can impact individuals and populations is unclear, in part due to our limited knowledge of the physiology and behavior of moose and how individuals can compensate for stress and disturbances they experience. We collected data from collar-mounted fine-scale tri-axial accelerometers deployed on captive moose in combination with detailed behavioral observations to train a random forest supervised classification algorithm to classify moose accelerometer data into discrete behaviors. To investigate the generalizability of our model to collared new individuals, we quantified the variation in classification performance among individuals.ResultsOur machine learning model successfully classified 3-s accelerometer data intervals from 12 Alaskan moose (A. a. gigas) and two European moose (A. a. alces) into seven behaviors comprising 97.6% of the 395 h of behavioral observations conducted in summer, fall and spring. Classification performance varied among behaviors and individuals and was generally dependent on sample size. Classification performance was highest for the most common behaviors lying with the head elevated, ruminating and foraging (precision and recall across all individuals between 0.74 and 0.90) comprising 79% of our data, and lower and more variable among individuals for the four less common behaviors lying with head down or tucked, standing, walking and running (precision and recall across all individuals between 0.28 and 0.79) comprising 21% of our data.ConclusionsWe demonstrate the use of animal-borne accelerometer data to distinguish among seven main behaviors of captive moose and discuss generalizability of the results to individuals in the wild. Our results can support future efforts to investigate the detailed behavior of collared wild moose, for example in the context of disturbance responses, time budgets and behavior-specific habitat selection.

Chlorine Distribution in Soil and Vegetation in Boreal Habitats along a Moisture Gradient from Upland Forest to Lake Margin Wetlands.

The assumed dominance of chloride (Cl-) in terrestrial ecosystems is challenged by observations of extensive formation of organically bound Cl (Clorg), resulting in large soil Cl storage and internal cycling. Yet, little is known about the spatial distribution of Cl in ecosystems. We quantified patterns of Cl distribution in different habitats along a boreal hillslope moisture gradient ranging from relatively dry upland coniferous forests to wet discharge areas dominated by alder. We confirmed that dry habitats are important for Cl storage but found that Cl pools tended to be larger in moist and wet habitats. The storage of Clorg was less important in wet habitats, suggesting a shift in the balance between soil chlorination and dechlorination rates. Cl concentrations in the herb layer vegetation were high in wet and moist sites attributed to a shift in plant species composition, indicating plant community-dependent ecosystem Cl cycling. Mass-balance calculations showed that internal Cl cycling increased overall ecosystem Cl residence times at all sites and that plant uptake rates of Cl- were particularly high at wet sites. Our results indicate that habitat characteristics including plant communities and hydrology are key for understanding Cl cycling in the environment.

Southern Record of the Xenobiotic Ant Formicoxenus quebecensis from Eastern Wisconsin

The ant genus Formicoxenus is notable for the fact that all its species are xenobiotic and live inside or in close association with the nests of other ant species. Here, we report the occurrence of a colony of Formicoxenus quebecensis and its host, Myrmica alaskensis from the eastern side of the Door peninsula in Wisconsin. Both species are new records for the state, and F. quebecensis was previously known only from boreal habitats much farther north in Canada. We also provide some observations on this colony’s nest demography, morphology, and feeding behavior and discuss the ant community of this biogeographically interesting location.

Host generalists dominate fungal communities associated with alpine knotweed roots: a study of Sebacinales.

Bistorta vivipara is a widespread herbaceous perennial plant with a discontinuous pattern of distribution in arctic, alpine, subalpine and boreal habitats across the northern Hemisphere. Studies of the fungi associated with the roots of B. vivipara have mainly been conducted in arctic and alpine ecosystems. This study examined the fungal diversity and specificity from root tips of B. vivipara in two local mountain ecosystems as well as on a global scale. Sequences were generated by Sanger sequencing of the internal transcribed spacer (ITS) region followed by an analysis of accurately annotated nuclear segments including ITS1-5.8S-ITS2 sequences available from public databases. In total, 181 different UNITE species hypotheses (SHs) were detected to be fungi associated with B. vivipara, 73 of which occurred in the Bavarian Alps and nine in the Swabian Alps–with one SH shared among both mountains. In both sites as well as in additional public data, individuals of B. vivipara were found to contain phylogenetically diverse fungi, with the Basidiomycota, represented by the Thelephorales and Sebacinales, being the most dominant. A comparative analysis of the diversity of the Sebacinales associated with B. vivipara and other co-occurring plant genera showed that the highest number of sebacinoid SHs were associated with Quercus and Pinus, followed by Bistorta. A comparison of B. vivipara with plant families such as Ericaceae, Fagaceae, Orchidaceae, and Pinaceae showed a clear trend: Only a few species were specific to B. vivipara and a large number of SHs were shared with other co-occurring non-B. vivipara plant species. In Sebacinales, the majority of SHs associated with B. vivipara belonged to the ectomycorrhiza (ECM)-forming Sebacinaceae, with fewer SHs belonging to the Serendipitaceae encompassing diverse ericoid–orchid–ECM–endophytic associations. The large proportion of non-host-specific fungi able to form a symbiosis with other non-B. vivipara plants could suggest that the high fungal diversity in B. vivipara comes from an active recruitment of their associates from the co-occurring vegetation. The non-host-specificity suggests that this strategy may offer ecological advantages; specifically, linkages with generalist rather than specialist fungi. Proximity to co-occurring non-B. vivipara plants can maximise the fitness of B. vivipara, allowing more rapid and easy colonisation of the available habitats.

The direct and habitat-mediated influence of climate on the biogeography of boreal caribou in Canada

Effective species conservation efforts require insight into whether a species’ extent of occurrence may shift due to changing climate, habitat loss, or both. The extent of occurrence of the threatened boreal population of woodland caribou (Rangifer tarandus caribou; caribou) has contracted due to environmental and anthropogenic disruption, with further contractions predicted as boreal habitat shifts with the changing climate. However, the direct and indirect climate drivers of caribou extent of occurrence have not been explicitly investigated. We estimated and compared the influence of climate and habitat drivers on the occurrence of caribou ranges across the Canadian boreal forest. We fit path models that estimated the direct effects of climate on caribou range occurrence and its indirect effect through climate's influence on caribou habitat (i.e., forest cover, presence of peatland, human disturbance and wildfire). Our analysis suggests that the distribution of caribou ranges is less sensitive to the direct effects of climate than to those of habitat and human disturbance. However, through its relationship to caribou habitat, climate exerts indirect influence over the distribution of caribou. As the climate changes, future distributions of caribou may be more heavily relegated to refuge habitats, particularly peatlands in the western boreal forest. Our biogeographical approach enables more informed decisions for large-scale caribou conservation efforts (e.g. establishment of protected areas, habitat restoration) that account for potential shifts in the distribution of caribou under changing environmental and climatic conditions.

Patterns of Genetic Variation in the Eisenia nordenskioldi Complex (Oligochaeta: Lumbricidae) along an Elevation Gradient in Northern China

Eisenia nordenskioldi is the dominant earthworm species in many tundra and boreal habitats. Nothing is known about the genetic diversity of this species along the elevation gradient in China. This study sampled 28 individuals in the E. nordenskioldi complex from Wuling Mountain, northern China, to examine their external morphology and genetic diversity. Mt. Wuling is the southern limit of the distribution of the E. nordenskioldi complex. The specimens from Mt. Wuling were classified into three groups along an elevation gradient. Mismatch distribution analysis suggested that the Pleistocene glaciations possibly did not significantly affect the distribution of earthworm species in this region. We also found that elevation affected the genetic diversity, but not the external morphology of E. nordenskioldi. Given the altitudinal genetic diversity within the E. nordenskioldi complex, the phylogeography of this species provides important information for the zoogeographic reconstruction of the mountains in northern China. With the relatively limited sample size, the result is not conclusive, and further studies need to be conducted in the future to verify the results.

High dietary and habitat diversity indicate generalist behaviors of northern bog lemmings Synaptomys borealis in Alaska, USA

The northern bog lemming Synaptomys borealis (NBL) is a rare small mammal that is undergoing a federal Species Status Assessment (SSA) under the US Endangered Species Act. Despite a wide North American distribution, very little is known about NBL dietary or habitat needs, both of which are germane to the resiliency of this species to climate change. To quantify diet composition of NBL in Alaska, we used DNA metabarcoding from 59 archived specimens to describe the taxonomic richness and relative abundance of foods in recent diets. DNA analyses revealed a broad diet composed of at least 110 families and 92 genera of bryophytes (mosses and liverworts), graminoids, fungi, forbs, and woody shrubs. Nine bryophyte genera and Carex sedges composed the largest portions of NBL diets. To quantify habitat preference, we intersected 467 georeferenced occurrence records of NBL in Alaska with remotely sensed land cover classes and used a compositional analysis framework that accounts for the relative abundance of land cover types. We did not detect significant habitat preferences for specific land cover types, although NBL frequently occurred in evergreen forest, woody wetlands, and adjacent to water. Our research highlights the importance of bryophytes, among a high diversity of dietary components, and describes NBL as boreal habitat generalists. Results will inform the current federal SSA by quantifying the extent to which ecological constraints are likely to affect NBL in a rapidly changing boreal environment.

The distribution and life history of Mysis gaspensis O.S. Tattersall, 1954 (Crustacea, Mysida): An almost endemic, nektonic component of Atlantic Canada estuarine and coastal ecosystems

Mysids (Mysida) or opossum shrimp are nektonic Crustacea found worldwide in freshwater, hypogean, coastal marine or deep-sea habitats. A poorly known, highly localized species Mysis gaspensis O.S. Tattersall, 1954 is found only in Atlantic Canada and Maine, USA. During spring to autumn, localized populations form aggregations at low tide in littoral estuarine environments but individuals also occur at littoral coastal sites. In boreal habitats, this mysid has a univoltine, semelparous life cycle. Beginning in March-April, juveniles are released from the female marsupium at 2.0-2.5 mm total length (TL). Growth in TL is linear (r2 = 0.90), and growth in wet weight is exponential (b = 2.96). Females attain 14.1-16.5 mm TL and males 13.9-25.5 mm TL, by November when they begin maturation.During November-January, penultimate and ultimate males and females migrate seaward where copulation is presumed to occur. Males die after copulation. Development of young during winter results in a mixture of embryo development stages in individual female marsupia by spring. Mean brood size is 59 embryos (range 32-83). Females reoccupy estuarine habitats during March-April and release their young. Females survive after release of young and attain a maximum length of ~20.0 mm TL, but most die or are predated upon by late July. Juveniles and adults of some populations form highly visible aggregations during low tide in the shallow water of estuaries occupying sites with low velocity currents (12-41 cm/s) and near the limit of salinity (0.5-19.0). Aggregations range in size up to 38,000 individuals but the population in some estuaries is often scattered at low tide in small groups or individuals on the down-stream side of rocks or underwater structures.Keywords: aggregations; brood size; growth; maturation; opossum shrimp; reproduction

Relative use of xeric boreal habitats by shrews (Sorexspp.)

AbstractFew studies have explicitly examined habitat use by shrews (Sorexspp.) in the boreal forest of western North America. We conducted pitfall trapping in six common xeric habitat types in Yukon, Canada, to determine their relative use by shrews. The overall capture rate was 0.47 shrews per 100 trap nights (TN), with a total sampling effort of 3652 TN. Cinereus shrews (Sorex cinereus; 0.25 per 100 TN) were the most common species, followed by dusky shrews (Sorex monticolus; 0.14 per 100 TN) and American pygmy shrews (Sorex hoyi; 0.08 per 100 TN). Shrew capture rates and species richness was low in all habitat types sampled. Cinereus shrews were captured in similar numbers in boreal mixedwood forest and alpine shrub habitats, and rarely in other lowland forest habitat types. Dusky shrews were captured largely in alpine shrub habitats, while pygmy shrews were captured only in lowland forest habitat types. The relative use of alpine shrub habitat by cinereus shrews and dusky shrews was not expected. Our data was limited by low captures; however, we provide a first approximation of the relative use of common forest types and subalpine shrub habitat in the boreal forest of northwestern Canada.

Plant and soil nitrogen in oligotrophic boreal forest habitats with varying moss depths: does exclusion of large grazers matter?

The boreal forest consists of drier sunlit and moister-shaded habitats with varying moss abundance. Mosses control vascular plant–soil interactions, yet they all can also be altered by grazers. We determined how 2 decades of reindeer (Rangifer tarandus) exclusion affect feather moss (Pleurozium schreberi) depth, and the accompanying soil N dynamics (total and dissolvable inorganic N, δ15N), plant foliar N, and stable isotopes (δ15N, δ13C) in two contrasting habitats of an oligotrophic Scots pine forest. The study species were pine seedling (Pinus sylvestris L.), bilberry (Vaccinium myrtillus L.), lingonberry (V. vitis-idaea L.), and feather moss. Moss carpet was deeper in shaded than sunlit habitats and increased with grazer exclusion. Humus N content increased in the shade as did humus δ15N, which also increased due to exclusion in the sunlit habitats. Exclusion increased inorganic N concentration in the mineral soil. These soil responses were correlated with moss depth. Foliar chemistry varied due to habitat depending on species identity. Pine seedlings showed higher foliar N content and lower foliar δ15N in the shaded than in the sunlit habitats, while bilberry had both higher foliar N and δ15N in the shade. Thus, foliar δ15N values of co-existing species diverged in the shade indicating enhanced N partitioning. We conclude that despite strong grazing-induced shifts in mosses and subtler shifts in soil N, the N dynamics of vascular vegetation remain unchanged. These indicate that plant–soil interactions are resistant to shifts in grazing intensity, a pattern that appears to be common across boreal oligotrophic forests.

Does artificial feeding affect large carnivore behaviours? The case study of brown bears in a hunted and tourist exploited subpopulation

Artificial food supplementation of wildlife is an increasing practice for species conservation, as well as for hunting and viewing tourism. Yet, our understanding of the implications of wildlife supplementary feeding is still very limited. Concerns have been raised over the potential negative impact of artificial feeding, but the effects of this practice on animal movements and rhythms of activity are just beginning to be investigated. Here, with the aim of studying whether the artificial feeding of brown bears may affect their behaviour, we analysed (1) the probability and intensity of feeding site use at different temporal scales, (2) how the use of artificial feeding sites is related to the bear's age and sex, main periods of the bear's annual cycle (i.e. mating and hyperphagia) and characteristics of the feeding sites, and (3) how the use of artificial feeding may be affecting bear movement patterns. We analysed the movements of 71 radio-collared brown bears in southern-central Finland and western Russian Karelia. Artificial feeding sites had several effects on brown bears in boreal habitats. The probability of a feeding site being used was positively correlated to the stability of this food resource over time, whereas sexes and bear classes (subadults, adults and females with cubs) did not show significant differences in the use of feeding sites, which were visited predominantly at night and slightly more during hyperphagia. The probability of using an artificial feeding site affected the daily net distance only (bears using feeding sites: 3.5 ± 4.5 km, range: 0–29 km; bears not using feeding sites: 4.4 ± 4.9 km, range: 0–47 km). Those brown bears using artificial feeding more intensively moved shorter distances at a lower speed within smaller home ranges compared to bears that used this food sources less. Highly predictable and continuously available anthropogenic food may therefore have substantial impacts on brown bear movement patterns, ecology and health. The recorded changes in movement patterns support the evidence that artificial feeding may have important implications for bear ecology and conservation.

A Comparison of All-Terrain Vehicle (ATV) Trail Impacts on Boreal Habitats Across Scales

ABSTRACT: Recreational trails are an agent of anthropogenic disturbance in nature reserves and other low human impact areas. Effective management must balance the desire of recreationists to use these natural areas with the need to maintain their ecological integrity. Environments with low productivity may be particularly susceptible due to low resistance and resilience to recreational impacts. Our study examined 28 all-terrain vehicle (ATV) trails within the Avalon Wilderness Reserve and the adjacent surrounding area on the island of Newfoundland, Canada. We found that different habitat types (boreal forest, heaths, and bogs) differ in resistance and resilience to both direct on-trail erosion and indirect off-trail vegetation impacts of ATV trails. Dry forested sites were more resistant to direct on-trail erosion but less resistant to indirect off-trail vegetation disturbance. Heath sites were less resistant to direct on-trail erosion but highly resistant to indirect off-trail disturbance. Bog sites had ...

The current state of Pleistocene Park, Russia (An experiment in the restoration of megafauna in a boreal environment)

Pleistocene Park is a protected area located near the Arctic Circle in the Eastern part of Russia. It was established by Sergey Zimov and his team in order to perform an experiment on the restoration of the environment that existed there during the Pleistocene period. It was expected that low-productivity boreal habitats would be replaced by highly-productive grasslands resembling African savanna. This experiment was launched in 1988, and its continuation is planned for the indefinite future. The territory of the park was surveyed recently and its actual state was characterized.

The Effects of Host Plant Species and Plant Quality on Growth and Development in the Meadow Spittlebug (Philaenus spumarius) on Kent Island in the Bay of Fundy

Philaenus spumarius (Meadow Spittlebug, Homoptera: Cercopoidea) is a cosmopolitan generalist insect that feeds on a wide repertoire of host plants in the field. We studied density and growth of Meadow Spittlebugs on a range of host plants on Kent Island, a boreal island in the Bay of Fundy, NB, Canada. The highest spittlebug densities were on Cirsium arvense (Canadian Thistle), although spittlebugs had larger body sizes on Solidago rugosa (Rough-stemmed Goldenrod) and Anaphalis margaritacea (Pearly Everlasting). We fertilized plots of Rough-stemmed Goldenrod in the field over 3 weeks to examine the effects of plant quality on development of Meadow Spittlebugs. Following fertilization, there were fewer nymphs present in fertilized plots than in unfertilized plots, indicating faster nymph maturation to adulthood on fertilized plants. This study offers an initial report of the host plants used by Meadow Spittlebugs in northeastern boreal habitat, variation in density and performance of the species on a range of host plants, and the effects of plant fertilization on spittlebug life history.

Temporal changes in avian community composition in lowland conifer habitats at the southern edge of the boreal zone in the Adirondack Park, NY

Climate change represents one of the most significant threats to human and wildlife communities on the planet. Populations at range margins or transitions between biomes can be particularly instructive for observing changes in biological communities that may be driven by climate change. Avian communities in lowland boreal habitats in the Adirondack Park, located at the North American boreal-temperate ecotone, have been the focus of long-term monitoring efforts since 2007. By documenting long-term changes in community structure and composition, such datasets provide an opportunity to understand how boreal species are responding differently to climate change, and which habitat characteristics may be best able to retain boreal avian communities. We examined three specific questions in order to address how well current biological communities in Adirondack boreal wetland habitats are being maintained in a changing climate: (1) how do trends in occupancy vary across species, and what guilds or characteristics are associated with increasing or decreasing occupancy? (2) how is avian community composition changing differently across sites, and (3) what distinguishes sites which are retaining boreal birds to a higher degree than other sites? Our analysis revealed that (1) boreal species appear to exhibit the largest changes in occupancy among our study locations as compared to the larger avian community, (2) dynamics of community change are not uniform across sites and habitat structure may play an important role in driving observed changes, and (3) the particular characteristics of large open peatlands may allow them to serve as refugia for boreal species in the context of climate change.

Phylogenetic study documents different speciation mechanisms within the Russula globispora lineage in boreal and arctic environments of the Northern Hemisphere

The Russula globispora lineage is a morphologically and phylogenetically well-defined group of ectomycorrhizal fungi occurring in various climatic areas. In this study we performed a multi-locus phylogenetic study based on collections from boreal, alpine and arctic habitats of Europe and Western North America, subalpine collections from the southeast Himalayas and collections from subtropical coniferous forests of Pakistan. European and North American collections are nearly identical and probably represent a single species named R. dryadicola distributed from the Alps to the Rocky Mountains. Collections from the southeast Himalayas belong to two distinct species: R. abbottabadensis sp. nov. from subtropical monodominant forests of Pinus roxburghii and R. tengii sp. nov. from subalpine mixed forests of Abies and Betula. The results suggest that speciation in this group is driven by a climate disjunction and adaptation rather than a host switch and geographical distance.

Wildlife usage indicates increased similarity between reclaimed upland habitat and mature boreal forest in the Athabasca Oil Sands Region of Alberta, Canada.

While there is no denying that oil sands development in the Athabasca Oil Sands Region (AOSR) has large impacts upon the habitat it disturbs, developers are legally required to return this land to “an equivalent land capability.” While still early in the process of reclamation, land undergoing reclamation offers an opportunity to study factors influencing reclamation success, as well as how reclaimed ecosystems function. As such, an Early Successional Wildlife Dynamics (ESWD) program was created to study how wildlife return to and use reclaimed upland boreal habitat in the AOSR. Wildlife data comprising 182 taxa of mammals, birds, and amphibians, collected between 2011 and 2017 and from five oil sands leases, were compared from multiple habitat types (burned [BRN], cleared [CLR], compensation lakes [COMP], logged [LOG], mature forest [MF], and reclaimed sites [REC]). Overall, similarity of wildlife communities in REC and MF plots varied greatly, even at 33 years since reclamation (31–62% with an average of 52%). However, an average community similarity of 52% so early in the successional process suggests that current reclamation efforts are progressing towards increased similarity compared to mature forest plots. Conversely, our data suggest that REC plots are recovering differently than plots impacted by natural (BRN) or other anthropogenic disturbances (LOG), which is likely due to differences associated with soil reconstruction and development on reclaimed plots. Regardless of the developmental trajectory of reclaimed habitats, progression towards increased wildlife community similarity at REC and MF plots is apparent in our data. While there is no expectation that reclaimed upland habitats will resemble or function identically to naturally occurring boreal forest, the degree of similarity observed in our study suggests that comparable ecological functionality is possible, increasing the probability that oil sands operators will be able to fulfill their regulatory requirements and duty to reclaim regarding wildlife and wildlife habitat.

Integrated modeling predicts shifts in waterbird population dynamics under climate change

Climate change has been identified as one of the most important drivers of wildlife population dynamics. The in‐depth knowledge of the complex relationships between climate and population sizes through density dependent demographic processes is important for understanding and predicting population shifts under climate change, which requires integrated population models (IPMs) that unify the analyses of demography and abundance data. In this study we developed an IPM based on Gaussian approximation to dynamic N‐mixture models for large scale population data. We then analyzed four decades (1972–2013) of mallard Anas platyrhynchos breeding population survey, band‐recovery and climate data covering a large spatial extent from North American prairies through boreal habitat to Alaska. We aimed to test the hypothesis that climate change will cause shifts in population dynamics if climatic effects on demographic parameters that have substantial contribution to population growth vary spatially. More specifically, we examined the spatial variation of climatic effects on density dependent population demography, identified the key demographic parameters that are influential to population growth, and forecasted population responses to climate change. Our results revealed that recruitment, which explained more variance of population growth than survival, was sensitive to the temporal variation of precipitation in the southern portion of the study area but not in the north. Survival, by contrast, was insensitive to climatic variation. We then forecasted a decrease in mallard breeding population density in the south and an increase in the northwestern portion of the study area, indicating potential shifts in population dynamics under future climate change. Our results implied that different strategies need to be considered across regions to conserve waterfowl populations in the face of climate change. Our modelling approach can be adapted for other species and thus has wide application to understanding and predicting population dynamics in the presence of global change.