Past Ecosystems Research Articles

How could sympatric megaherbivores coexist? Example of niche partitioning within a proboscidean community from the Miocene of Europe

Although low in diversity, megaherbivores (mammals weighting over 10(3) kg) and especially proboscideans have a powerful impact on the structure and dynamics of present-day ecosystems. During the Neogene (23 to 2.6 Ma) of Europe, the diversity and geographic distribution of these megaherbivores was much greater. Nonetheless, their role in past ecosystems is unclear. Nutrition is one of the main bonds between organisms and their environment. Therefore, the ecology of organisms can be inferred from their dietary habits. The present study is aimed at characterizing the feeding habits of diverse megaherbivores through dental microwear analyses. This method was applied on cheek teeth of three sympatric species of proboscideans from the middle/late Miocene of the Molasse Basin in Southern Germany: Gomphotherium subtapiroideum, Gomphotherium steinheimense, and Deinotherium giganteum. The microwear signatures are significantly different between these taxa, suggesting differences in feeding habits and ecological niches within a woodland environment. D. giganteum probably browsed on dicotyledonous foliages whereas the two species of gomphotheres were neither strict grazers nor strict browsers and instead probably fed on a large spectrum of vegetal resources. The differences of occlusal molar morphology between the two gomphotheres are supported by the dental microwear pattern. Indeed, G. subtapiroideum probably ingested more abrasive material than G. steinheimense. Thus, our results suggest that these proboscideans did not compete for food resources.

The sea ahead: challenges to marine biology from seafood sustainability

Many have documented the litany of disaster and depletion suffered by living organisms in the world’s oceans, where today anthropogenic impacts from fisheries and pollution on biodiversity and resilience are further exacerbated by threats of climate change. At the same time, the demand for sustainable seafood has never been greater. By presenting three challenges to marine biology, this article explores how we may be able to throw light upon practical measures that can mitigate, redress and avert some of the worst future scenarios whilst continuing to supply, and even increase, economic, social and nutritional benefits from seafood. First, I present a rigorous, multi-disciplinary, semi-quantitative ecosystem evaluation framework (EEF) that characterises the essential ecological features of different marine ecosystems and can evaluate the status of threats. The general framework is designed to work in the face of ignorance and quantifies uncertainty. An example is presented from recent work on seamounts. Second, a desperate need for food supplies will almost inevitably lead to further fishing down the trophic levels in marine food webs. Some have argued to do this deliberately to mitigate global problems of hunger, especially in the face of concerns about the sustainability of terrestrial agriculture, and we can be sure that economic pressures and market values for increasingly scarce protein will lead to tendencies of this type. One example is a possible increased exploitation of krill, which at first sight presents vastly increased amounts of protein that could be harvested. Here, I show how large but potentially sustainable levels of catch may be estimated in a precautionary fashion. Third, inter alia, a practical restoration agenda is discussed. The importance of historical reconstruction is exemplified by ‘back to the Future’ research which attempts to use quantitative descriptions of past ecosystems to emplace practical restoration goals for management (such as Optimal Restorable Biomass, ORB), while quantifying risks in the management of marine ecosystems from climate and uncertainty. All three areas and their examples represent work-in-progress, and their credibility and utility pivot on the quality of our insight into critical ecological processes and on the widespread adoption of rational, precautionary policies. Moreover, they present profound scientific and human challenges to the science of marine biology.

Extinction rate, historical population structure and ecological role of the Caribbean monk seal

The productivity and biomass of pristine coral reef ecosystems is poorly understood, particularly in the Caribbean where communities have been impacted by overfishing and multiple other stressors over centuries. Using historical data on the spatial distribution and abundance of the extinct Caribbean monk seal (Monachus tropicalis), this study reconstructs the population size, structure and ecological role of this once common predator within coral reef communities, and provides evidence that historical reefs supported biomasses of fishes and invertebrates up to six times greater than those found on typical modern Caribbean reefs. An estimated 233,000-338,000 monk seals were distributed among 13 colonies across the Caribbean. The biomass of reef fishes and invertebrates required to support historical seal populations was 732-1018 gm(-2) of reefs, which exceeds that found on any Caribbean reef today and is comparable with those measured in remote Pacific reefs. Quantitative estimates of historically dense monk seal colonies and their consumption rates on pristine reefs provide concrete data on the magnitude of decline in animal biomass on Caribbean coral reefs. Realistic reconstruction of these past ecosystems is critical to understanding the profound and long-lasting effect of human hunting on the functioning of coral reef ecosystems.

Transdisciplinary challenges in landscape ecology and restoration ecology: reconciling nature and society

Early on in the 1970s IUCN recognized that effective conservation could not be achieved by focusing on traditional eco-centric approaches alone and that it was necessary to involve humans and cultural landscapes. Subsequently to that many conventions brought landscapes to the worldwide political agenda with the fairly recent example of the European Landscape Convention. Each of these emphasizes the need for protection of the natural and cultural landscapes of an area as a whole and recognises that landscape scale approaches are fundamental to the understanding not just of past and present ecosystem patterns and processes but also cultural ones. This is an idea that was promoted by the author of this book very early in the foundation of landscape ecology where landscape was seen as the fabric that integrates nature and culture. This book encompasses Zev Naveh’s work of 40 years (1967–2007) in the fields of landscape and restoration ecology presented in a collection of papers published so far in scientific journal or books. The topics covered herein are of great breadth ranging from applied ecology and conservation such as fire, vegetation and habitat management to eloquent philosophical debates regarding the reconciliation of society and nature and the future of the discipline. As such, it illustrates well-adopted concepts such as holism and the multifunctionality of landscapes but also initiatives such as the Green Books for Threatened Landscapes that unfortunately was never widely adopted. The book starts with a review of the chapters by the author with the inclusion of some autobiographical comments and is further divided in three parts:

Environmental History, Traditional Populations, and Paleo-territories in the Brazilian Atlantic Coastal Forest

Abstract This article examines the long-run anthropogenic factors that have affected the Atlantic Coastal Forest, where human activities was one of the ecological factors that influenced the biome, which formerly covered almost the entire Brazilian coast. The author proposes the concept of “paleo-territories” as part of this analysis of sucessional processes. The expression refers to the spatialization of influences of past ecosystem usage by a specific traditional population or economic cycle. A paleo-territory is the anthropogenic portion of the biotic and abiotic processes that affect the regeneration of forests, in which both the culture and technology of traditional human populations play a determining role. As such, the Atlantic Coastal Forest exhibits ecological attributes that reflect the long history of the co-existence of these populations within the regional ecosystem, and may hence not be a fully “natural” biome. The major impact of humans on the Atlantic Coastal Forest makes it imperative for any study of forest ecology to take account of human activity.

DNA evidence for historic population size and past ecosystem impacts of gray whales

Ecosystem restoration may require returning threatened populations of ecologically pivotal species to near their former abundances, but it is often difficult to estimate historic population size of species that have been heavily exploited. Eastern Pacific gray whales play a key ecological role in their Arctic feeding grounds and are widely thought to have returned to their prewhaling abundance. Recent mortality spikes might signal that the population has reached long-term carrying capacity, but an alternative is that this decline was due to shifting climatic conditions on Arctic feeding grounds. We used a genetic approach to estimate prewhaling abundance of gray whales and report DNA variability at 10 loci that is typical of a population of approximately 76,000-118,000 individuals, approximately three to five times more numerous than today's average census size of 22,000. Coalescent simulations indicate these estimates may include the entire Pacific metapopulation, suggesting that our average measurement of approximately 96,000 individuals was probably distributed between the eastern and currently endangered western Pacific populations. These levels of genetic variation suggest the eastern population is at most at 28-56% of its historical abundance and should be considered depleted. If used to inform management, this would halve acceptable human-caused mortality for this population from 417 to 208 per year. Potentially profound ecosystem impacts may have resulted from a decline from 96,000 gray whales to the current population. At previous levels, gray whales may have seasonally resuspended 700 million cubic meters of sediment, as much as 12 Yukon Rivers, and provided food to a million sea birds.

Plant Functional Types and Plant Trait Measurements in the Eastern Ghats, South India

Classifying terrestrial plant species on the basis of function rather than on taxonomy facilitates addressing ecological questions at the scale of ecosystems, landscapes or Biomes. The concept of plant functional types (PFTs) helps handle taxonomic diversity, as it groups together species that share common attributes with respect to, e.g. life-form, phenology and bioclimatic limits. For some time now, large international efforts promoted by the IGBP-GCTE programme are underway to measure for a large number of species a shortlist of significant plant traits that would underlie such functional plant classification systems. The idea here is to help address vegetation responses to and vegetation effects on environmental changes such as climate changes, but also others such as landuse or other disturbances. A PFT classification obviously helps in the use of pollen assemblages to infer past ecosystem changes, especially ecosystem response to climate change, as this is more directly linked to changes in functional rather than taxonomic diversity of plants over temporal and spatial gradients. We present a comprehensive list of pollen taxa from our database of surface samples from Eastern Ghats, South India to which PFTs are assigned based on our field observations of the Ecology and Biology of individuals as well as the description of the flora and vegetation of the Eastern Ghats in standard published floras. Finally, we also present trait measurements such as specific leaf area (SLA) and thickness for a shortlist of the taxa listed above.

Plant Functional Types and Plant Trait Measurements in the Eastern Ghats, South India

AbstractClassifying terrestrial plant species on the basis of function rather than on taxonomy facilitates addressing ecological questions at the scale of ecosystems, landscapes or Biomes. The concept of plant functional types (PFTs) helps handle taxonomic diversity, as it groups together species that share common attributes with respect to, e.g. life-form, phenology and bioclimatic limits. For some time now, large international efforts promoted by the IGBP-GCTE programme are underway to measure for a large number of species a shortlist of significant plant traits that would underlie such functional plant classification systems. The idea here is to help address vegetation responses to and vegetation effects on environmental changes such as climate changes, but also others such as landuse or other disturbances.A PFT classification obviously helps in the use of pollen assemblages to infer past ecosystem changes, especially ecosystem response to climate change, as this is more directly linked to changes in functional rather than taxonomic diversity of plants over temporal and spatial gradients. We present a comprehensive list of pollen taxa from our database of surface samples from Eastern Ghats, South India to which PFTs are assigned based on our field observations of the Ecology and Biology of individuals as well as the description of the flora and vegetation of the Eastern Ghats in standard published floras. Finally, we also present trait measurements such as specific leaf area (SLA) and thickness for a shortlist of the taxa listed above.

Reconstructing past population processes with general equilibrium models: House mice in Kern County, California, 1926–1927

Reconstructing past ecosystem conditions is helpful in addressing a range of basic and applied questions, but difficult because of a lack of inferential or modeling approaches. Here, we demonstrate the use of a general equilibrium ecosystem model (GEEM) to investigate ecological conditions surrounding a population eruption of the house mouse ( Mus musculus) in Kern County, California in the 1920s, arguably the most dramatic mammalian population eruption reported for North America. Our application of GEEM to this ecosystem allowed us to evaluate the plausibility of reported population densities of house mice that were extreme, even in comparison with values for the same species introduced in Australia, and to examine alternative hypothetical community interactions and their effects on populations. The modeled ecosystem included vegetation, native small rodents and introduced house mice as herbivores, and mammalian predators. Individual plants and animals behaved as net energy optimizers, with net energy directed to reproduction. Optimizing predators determined the biomass taken from prey, and prey, through feeding choices, determined their vulnerability to predators. Model inputs incorporated the competitive superiority of house mice to native small rodents, the time of arrival of house mice in the area, and the timing and intensity of predator removal. Without an invasion of house mice, human removal of predators was predicted to minimally affect native small rodents. Without human removal of predators, invading house mouse populations were predicted to attain high, oscillating densities by the 1920s that stabilized at lower densities by the 1930s, with native small rodents persisting in the area. With near-complete human removal of predators and with house mice present, native small rodents were predicted to go nearly extinct, and house mice to attain densities similar to those reported. The predicted lag between the introduction and eruption of house mice approximated reported values. Predation on native and introduced rodents was predicted to allow both rodent groups to coexist, whereas near-complete removal of predators caused native small rodents to approach extinction during the house mouse eruption, consistent with empirical studies. GEEM appears to be a useful tool for reconstructing past ecosystem conditions and trophic interactions.

Establishment of the North Eastern Soil Monitoring Cooperative

A workshop organized by Greg Lawrence and Scott Bailey to establish the cooperative was held at the New York Water Science Center, Troy, New York, USA on 6–7 March 2007. Environmental monitoring is an essential tool for identifying the effects of human activities on the biosphere and for evaluating government policies designed to ameliorate these effects. The need for environmental data has led to national programs to monitor atmospheric deposition, the composition and growth of forests, and the chemistry of lakes and streams in regions affected by acidic deposition. However, there has been no organized effort to date to monitor changes in soils despite their importance to agriculture, forest growth, wetlands, and water quality, and their susceptibility to environmental stresses such as acidic deposition and climate change. The lack of attention given to soil monitoring can be attributed, in part, to questions regarding its feasibility. These questions derive from a common belief that soils are more likely to change over centuries than decades, and the knowledge that soils are highly variable in both vertical and horizontal space, a characteristic that complicates repeated sampling of the same soil. Within the past 15 years, however, changes in soil chemistry in eastern North America and Europe have been measured through resampling in a variety of soil types, over sampling intervals as short as 5 years. More opportunities for measuring soil change are becoming available through early investigations of acidic deposition effects, as well as other past ecosystem studies. As the number of these studies has grown, so too has the recognition that methods for sample collection and analysis are not always compatible, and methods for archiving are not well developed. Without established protocols that are both effective, and consistent among studies, the transfer value of individual studies is limited. To promote the coordinated collection of high-quality data on soil change, the first workshop on soil monitoring in the Northeastern United States and Eastern Canada was held to organize interested individuals and institutions into a cooperative network. The workshop was sponsored by the Northeastern States Research Cooperative and the New York State Energy Research and Development Authority (NYSERDA). Representatives from nine federal and state agencies from the United States and Canada participated, along with faculty and students from eight academic institutions. The workshop began with invited presentations on the possibilities and pitfalls of soil resampling by Arthur Johnson, University of Pennsylvania; Daniel Richter, Duke University; and Scott Bailey, USDA Forest Service. The next segment of the workshop involved discussions in which the mission of the cooperative was defined and specific objectives were identified, such as the development and sharing of field and laboratory protocols, the compilation of an inventory of historic and ongoing studies that could contribute information on soil change, and the design of a rigorous data collection program that will address emerging issues, as well as provide long-term continuity. Discussion followed on the steps needed to accomplish these objectives, including how to design sampling plots, appropriate methods for soil collection, the need for shared reference samples, and the development of effective archiving protocols. An additional objective of the cooperative will be to synthesize available information on methods into recommendations that will be published as agency or institutional reports. On the second day of the workshop, task groups were formed to address a number of issues involving methods, compilation of available data, and identification of ongoing studies. A steering committee was formed to guide the ongoing development of the cooperative. A journal article that will serve as a literature review of soil resampling was also outlined by interested workshop participants. A second workshop is planned for late Fall 2007. Web site planning is in the early stages, but information is available at: <http://www.czen.org/og/subscribe/364> Greg Lawrence (518) 285-5664 E-mail: glawrenc@usgs.gov or Scott Bailey (603) 535-3262 E-mail: swbailey@fs.fed.us

Spores of coprophilous fungi from under the Dawson tephra (25,300 14C years BP), Yukon Territory, northwestern Canada

Based on the analysis of pollen and macrofossils Zazula et al. [Zazula, G.D., Froesne, D.G., Elias, S.A., Kuzmina, S., la Farge, C., Reyes, A.V., Sanborn, P.T., Schweger, C.E., Smith, C.A.S., Mathewes, R.W., 2006. Vegetation buried under Dawson tephra (25,300 14C yr BP) and locally diverse late Pleistocene paleoenvironments of Goldbottom Creek, Yukon, Canada. Palaeogeography, Palaeoclimatology, Palaeoecology 242, 253–286.] reported an in situ riparian grassy meadow ecosystem, and regional well-drained steppe-tundra, buried by Dawson tephra (ca 25,300 BP) at Goldbottom Creek in the Canadian Yukon Territory. An additional study of fungal spores in pollen slides from that site was completed. Ascospores of the coprophilous Sordaria type, Sporormiella type and Podospora type, appeared to be of common occurrence, pointing to the former presence of herbivores. The analysis of the various spore types of coprophilous fungi in pollen slides is useful and may lead to further knowledge of the role of different herbivore taxa in past ecosystems.

Evolution of organic matter indicators in response to major environmental changes: The case of a formerly cut-over peat bog (Le Russey, Jura Mountains, France)

To assess whether the biochemical characteristics of peat can provide clues for past ecosystem changes or not, a study was carried out combining elemental analysis, micro-morphological counts and neutral monosaccharide determination of peat organic matter (OM) and the dominant living plants from a formerly cut-over peat bog in the Jura Mountains. Peat profiles (up to 50 cm depth) from two distinctive zones (bare peat, FRA and a regenerating stage, FRC) were compared with the reference profile (FRD) taken from an unexploited area of the bog. The results show contrasting OM composition along the profiles. In the upper sections of the FRD and FRC profiles, high C/N ratios and sugar contents (in the same range as in the source plants) and the large predominance of well preserved plant tissues indicate good preservation of primary biological inputs. In contrast, in peat from the FRA profile and deeper levels of the FRC profile, lower C/N ratios, lower amounts of sugars and a predominance of amorphous OM and mucilage suggest more extensive OM degradation. These features delineate a clear threshold between an uppermost “new” regenerating peat section and an “old” catotelm peat below. Nevertheless, even in the latter, the sugar contents remain relatively high (>80 mg/g) compared with other organic and mineral soils. Analysis of typical peat-forming plants and of bulk peat and fine grained fractions allowed identification of the following source indicators: xylose and arabinose for Cyperaceae; rhamnose, galactose and mannose for mosses; and ribose (and to a lesser extent, hemicellulosic glucose) possibly for microbial synthesis.

Early Cretaceous terrestrial ecosystems in East Asia based on food-web and energy-flow models

In recent years, there has been global interest in the environments and ecosystems around the world. It is helpful to reconstruct past environments and ecosystems to help understand them in the present and the future. The present environments and ecosystems are an evolving continuum with those of the past and the future. This paper demonstrates the contribution of geology and paleontology to such continua. Using fossils, we can make an estimation of past population density as an ecosystem index based on food-web and energy-flow models. Late Mesozoic nonmarine deposits are distributed widely on the eastern Asian continent and contain various kinds of fossils such as fishes, amphibians, reptiles, dinosaurs, mammals, bivalves, gastropods, insects, ostracodes, conchostracans, terrestrial plants, and others. These fossil organisms are useful for late Mesozoic terrestrial ecosystem reconstruction using food-web and energy-flow models. We chose Early Cretaceous fluvio-lacustrine basins in the Choyr area, southeastern Mongolia, and the Tetori area, Japan, for these analyses and as a potential model for reconstruction of other similar basins in East Asia. The food-web models are restored based on taxa that occurred in these basins. They form four or five trophic levels in an energy pyramid consisting of rich primary producers at its base and smaller biotas higher in the food web. This is the general energy pyramid of a typical ecosystem. Concerning the population densities of vertebrate taxa in 1 km 2 in these basins, some differences are recognized between Early Cretaceous and the present. For example, Cretaceous estimates suggest 2.3 to 4.8 times as many herbivores and 26.0 to 105.5 times the carnivore population. These differences are useful for the evaluation of past population densities of vertebrate taxa. Such differences may also be caused by the different metabolism of different taxa. Preservation may also be a factor, and we recognize that various problems occur in past ecosystem reconstructions. Counts of small numbers of confirmed species and estimates of maximum numbers of species present in the basin are used for the analysis and estimation of energy flow. This approach applies the methods of modern ecosystem analysis.

Human–environment interactions: learning from the past

The analysis of palaeoenvironmental archives—sediments, archaeological remains, tree-rings, documents and instrumental records—is presented as a key element in the global scientific endeavour aimed at understanding human–environment interactions at the present day and in the future. The paper explains the need for the focus on palaeoenvironmental studies as a means of ‘learning from the past’, and presents the rationale and structure of the IGBP-PAGES Focus 5 programme ‘Past Ecosystem Processes and Human–Environment Interactions’. The past, as described through palaeoenvironmental studies, can yield information about pre-impact states, trajectories of recent change, causation, complex system behaviour, and provide the basis for developing and testing simulation models. Learning from the past in each of these epistemological categories is exemplified with published case-studies.

Human–environment interactions: towards synthesis and simulation

Leaders of the PAGES Focus 5 programme ‘Past Ecosystem Processes and Human–Environment Interactions’ identify key issues for research on human–environment interactions for wider discussion. These include the need for long-term perspectives, the opportunities for maximising palaeoenvironmental research, the need for integration and regionalisation and the challenge of developing dynamic simulation models. A new organisational matrix for regional studies is outlined, based on a series of zonal/azonal regions and on the degree of human impact. Future priorities for palaeoenvironmental research include new studies in degraded human-dominated landscapes, highly-valued ecosystems and sites relevant to other IGBP Core Projects. Simulation of future human–environment interactions using modelling approaches that have been tested against long records lags behind global climate modelling, but cellular approaches for biogeophysical and multi-agent systems show promise.

A Late Neolithic vertebrate food web based on stable isotope analyses

Stable carbon and nitrogen isotope analyses of bone collagen, and stable carbon and oxygen isotope analyses of the bone's structural carbonate, were performed on 120 individuals representing 33 vertebrate species, including a single human bone find, collected from the Late Neolithic settlement at Pestenacker, Bavaria, Germany. We were thus capable of reconstructing a rather complex food web and could also address particular issues, such as whether humans influenced the diet of their domestic animals as opposed to their wild relatives, or whether humans perhaps had to compete over food with their domesticates. A rather unexpected result was that freshwater fish, which could be captured in the nearby river Lech, a major tributary of the Danube, contributed to the human diet only occasionally. As for mammals, it was also possible to recognise different trophic levels for birds and aquatic vertebrates, applying stable isotope analyses to both bone collagen and structural carbonate. In the case of fish, δ18O values at least revealed a physiological regularity in terms of temperature preference, besides diet. Conceivably, variability of δ18O in surface water as reflected, for example, by species that avoided human settlements, may help to characterise past ecosystems and to define site catchment exploited by Neolithic man in the course of food acquisition. Copyright © 2006 John Wiley & Sons, Ltd.

Zooarchaeology and conservation biology

Many modern ecological problems such as rain forest destruction, decreasing marine harvests, and fire suppression are directly or indirectly anthropogenic. Zooarchaeology and Conservation Biology presents an argument that conservation biology and wildlife management cannot afford to ignore zooarchaeological research the identification and analysis of faunal remains recovered from archaeological deposits. The editors contend that we can learn important lessons by studying long-term human and nonhuman influences on biota and ecosystems. From this perspective we can begin to understand biogeographic dynamics and behavioral patterns that are invisible to researchers who study living organisms over just a small span of years. The focus of this volume is on the North American faunal record. Contributors identify a specific management or conservation issue, describe and analyze relevant zooarchaeological data, and offer recommendations or at least establish a baseline for possible resolution. The volume brings together both case studies and research about past ecosystems, and examines how such knowledge can be of current utility and relevance.

Past ecosystem processes and human-environment interactions

Past ecosystem processes and human-environment interactions

Back–to–the–future: a fresh policy initiative for fisheries and a restoration ecology for ocean ecosystems

'Back-to-the-future' (BTF) is an integrative approach to a restoration ecology of the oceans that attempts to solve the fisheries crisis. To this end, it harnesses the latest understanding of ecosystem processes developments in whole ecosystem simulation modelling, and insight into the human dimension of fisheries management. BTF includes new methods for describing past ecosystems, designing fisheries that meet criteria for sustainability and responsibility, and evaluating the costs and benefits of fisheries in restored ecosystems. Evaluation of alternative policy choices, involving trade-offs between conservation and economic values, employs a range of economic, social and ecological measures. Automated searches maximize values of objective functions, and the methodology includes analyses of model parameter uncertainty. Participatory workshops attempt to maximize compliance by fostering a sense of ownership among all stakeholders. Some challenges that have still to be met include improving methods for quantitatively describing the past, reducing uncertainty in ecosystem simulation techniques and in making policy choices robust against climate change. Critical issues include whether past ecosystems make viable policy goals, and whether desirable goals may be reached from today's ecosystem. Examples from case studies in British Columbia, Newfoundland and elsewhere are presented.

The millennial dynamics of a boreal forest stand from buried trees

Summary We reconstructed the dynamics of a black spruce (Picea mariana) and jack pine (Pinus banksiana) forest stand in northern Québec using a continuous, 5200‐year‐long sequence of stem remains buried in adjacent peatland. Simulations of recruitment of such remains provided guidelines for inferring past ecosystem structure and composition at the stand scale. Compared with the late Holocene (4650–0 cal. year BP (CYBP)), the mid Holocene (5200–4650 CYBP) period was characterized by faster tree growth, larger stems and higher stem density, indicating higher forest productivity in association with a milder climate. The presence of stem remains of both species from 17 out of 20 contiguous 250‐year time intervals suggests that the spruce‐pine stand exhibited high compositional stability, with both species regenerating after fire from canopy‐stored seed banks. Relative species abundance closely followed the duration of past fire intervals deduced from the number of tree rings in buried conifers. Time periods of long (4650–3950, 3400–1850 and 250–0 CYBP) and short fire intervals (4950–4650, 3950–3400 and 1850–250 CYBP) were associated, respectively, with decreasing and increasing pine abundance, probably reflecting faster juvenile growth, lower shade tolerance, earlier sexual maturity and shorter longevity in jack pine compared with black spruce. We conclude that both climate change and climate‐induced fire disturbance have been driving long‐term ecosystem dynamics. Our field evidence supports the idea that interactions between disturbances and the life‐history traits of species modulate the impact of climate change at the scale of forest stands. At the same time, disturbances may result in long‐term stability of disturbance‐adapted ecosystems.