Landscape composition and habitat quality influence the abundance, population structure, and movements of animals. Understanding how an animal interacts with elements of the landscape helps predict its response to habitat loss and changes in land cover. We tested the hypothesis that the extent of movement depends on landscape composition in a threatened freshwater turtle, Emydoidea blandingii. We measured habitat composition at multiple spatial scales, ranging from the home range to the landscape scale. We built multiple linear regression models to predict home range size from the proportional use of 5 land-use categories, while controlling for intrinsic factors (sex, body size). We found that landscape composition significantly influenced home range size in the Blanding's turtle; however, the models explained a low proportion of the observed variation in home range size, meaning that landscape composition had a weak effect on movement. Our results also suggest that sex and body size have little influence on home range size in Blanding's turtles. More research is needed to determine the factors driving movement in this species, and overall, we recommend cautious use of models predicting space use as a function of landscape composition in a conservation context.

To explore whether leaf traits and trait relationships varied during progressive succession within the understory and canopy layers, specific leaf area (SLA), leaf nitrogen (N) and phosphorus (P) concentrations (mass- and area-based), and photosynthetic capacity (A: mass- and area-based) of tropical woody vegetation were measured in 2 layers in 3 successional stages of tropical forests. For understory plants, 4 out of 7 leaf traits varied significantly along the successional stages. The slopes of the N_mass—SLA and P_mass—SLA relationships were steeper in early than in intermediate and old-growth forests. The slopes of the N_mass—A_mass, P_masS—A_mass' and SLA—A_mass relationships did not differ among the 3 successional stages, but the y-intercepts were higher in early than in intermediate and old-growth forests. The slope of the N_mass—P_mass relationship changed little along the successional gradient, but the y-intercepts were higher in old-growth forest than in early and intermediate successional forests. For canopy trees, 3 out of 7 leaf traits changed significantly, but the slopes of 6 bivariate relationships remained invariant over the successional chronosequence. However, the y-intercepts of the N_mass—A_mass and SLA—A_mass relationships were higher in early and intermediate forests than in old growth forest, and the y-intercept of the N_mass—P_mass relationship was higher in early than in intermediate and old-growth forests. These results show that understory plants adjusted their SLA to adapt to environmental conditions more readily in intermediate and old-growth forests than in early successional forest. Resource allocation strategies did not differ within the canopy layers during the successional progress, and variations in photosynthetic nitrogen and phosphorus use efficiency (PNUE/PPUE) and N:P ratios were unrelated to resource allocation strategies, but likely responded to environmental pressures.

Seeds of Arctic plants face numerous threats prior to dispersal. The growing season varies across years in terms of degree days, and herbivory, predation, and pathogens are critical threats. In this study the results of different densities of the Arctic seed bug, Nysius groenlandicus (Heteroptera), piercing the seed coat of Silene acaulis and sucking out nutritional content were observed. In order to study the effect of Nysius groenlandicus on seed mass and germination of Silene acaulis, seeds were placed in Petri dishes with different densities of seed bugs. The herbivory affected the seed mass, leading to an average mass loss of 3.0% in fed-upon seeds compared to non-fed-upon seeds. However, the average seed mass lost seemed independent of the densities of seed bugs. A significant negative correlation between seed mass loss and number of germinations for seeds exposed to seed bugs was found. Furthermore, the germination speed of the seeds increased with increasing density of Nysius groenlandicus. The significance of this interaction is discussed, and we hypothesize that feeding might benefit the establishment of seedlings.

We studied riparian species distribution patterns along 4 rivers in 2 Mediterranean regions, an island and a continental area. Our aim was to determine the following aspects at 2 spatial scales: i) floristic patterns; ii) major gradients affecting riparian flora; iii) the role of biogeography on riparian vegetation. A stratified random sampling design with segments identified as strata was used. Univariate and multivariate statistics were applied to detect patterns of variation in the species data and main floristic gradients. At regional scale, variation in life forms and phytogeographical element composition showed strongest correlations with climatic variables. At local scale only the continental rivers had many differences in phytogeographical elements linked to their greater length with respect to insular rivers. With regard to the distributions of the riverbed flora, geography emerged as the main gradient at the regional scale. The structural gradient was important at local scale, even if the lateral gradient drove the greatest variation in vegetation composition in continental rivers. Variance partitioning underlined that the biogeographical location strongly affected riverbed flora patterns. Our results support the idea that the flora of Mediterranean riparian ecosystems is not strictly “azonal” but can be defined as “semi-azonal”. Species distribution showed a strong association with climate, which was the primary correlate of change in floristic composition between riparian sites at both scales.

Traditional knowledge has become a topic of considerable interest within the research and development environment. The contribution of traditional knowledge to conservation and management is increasingly recognized, and implementation endeavours are underway in several countries. The current scale of ecosystem degradation underscores the need for restoration interventions. It is increasingly recognized that successful ecological restoration depends on effective coordination of science and traditional ecological knowledge. This paper synthesizes the literature to evaluate the present and potential contribution of traditional knowledge to ecological restoration. Despite a growing number of articles published on traditional knowledge, only a few have addressed its contributions to ecological restoration per se. The main contributions of traditional knowledge to ecological restoration are in construction of reference ecosystems, particularly when historical information is not available; species selection for restoration plantations; site selection for restoration; knowledge about historical land management practices; management of invasive species; and post-restoration monitoring. Traditional knowledge and science are complementary and should be used in conjunction in ecological restoration projects. Incorporation of traditional knowledge can contribute to build a strong partnership for the successful implementation of restoration projects and increase their social acceptability, economical feasibility, and ecological viability.

To advance understanding of the mechanisms underpinning the coexistence of Mediterranean oak species, we conducted a year-long analysis of the production, architecture, and mycorrhization status of the fine roots of a mixed evergreen (Quercus ilex) and winter deciduous (Quercus faginea) oak stand. We used the ingrowth bag technique to sample the fine roots produced by each species in spring, summer, and winter. For each season, root architecture traits (specific root length, root diameter, root tips) and variables associated to root ectomycorrhizal status were measured in the laboratory. Results showed a marked seasonality in the fine root architecture, including more fine root tips and longer roots per unit of weight formed in spring and summer, revealing a capacity in Mediterranean oak species to modify root architecture in spring and suggesting the possibility of increased resource capture in summer. Fine root ectomycorrhizal status was comparable between species and also showed marked seasonality: we found a high percentage of roots colonized by dead ectomycorrhizas in winter but low ectomycorrhizal colonization rates in summer. Quercus ilex produced greater amounts of fine roots than Q. faginea (particularly during spring), suggesting greater competitive ability in the former species for belowground resources.

Pour accroître notre compréhension des mécanismes supportant la coexistence d'espèces méditerranéennes de chênes, nous avons analysé sur une année la production, l'architecture et le statut mycorhizien des radicelles d'un peuplement mixte de chênes à feuilles persistantes (Quercus ilex) et caduques (Quercus faginea). Nous avons utilisé la technique du sac de croissance pour échantillonner les radicelles produites par chaque espèce au printemps, à l'été et en hiver. Pour chaque saison, différents traits architecturaux des racines (longueur spécifique de la racine, diamètre de la racine, apex racinaire) et des variables associées au statut ectomycorhizien des racines ont été mesurés en laboratoire. Les résultats ont démontré une saisonnalité marquée dans l'architecture des radicelles. Au printemps et à l'été, une plus grande quantité d'apex racinaires et des racines plus longues par unité de poids étaient formées, révélant ainsi la capacité de ces espèces méditerranéennes de chênes à modifier l'architecture racinaire au printemps et suggérant une meilleure acquisition des ressources en été. Le statut ectomycorhizien des radicelles était comparable entre les espèces et montrait également une saisonnalité marquée puisque nous avons trouvé un pourcentage élevé de racines colonisées par des ectomycorhizes mortes en hiver, mais en été les taux de colonisation par des ectomycorhizes étaient faibles. Q. ilex a produit plus de radicelles que Q. faginea (particulièrement au printemps) ce qui suggère une plus grande compétitivité de la première pour les ressources souterraines.

Nomenclature: Ruiz de la Torre, 2006.

Beaver activity is often considered a hydrologic disturbance that “resets” succession. We determined how beaver impoundment and wetland size and water chemistry affected the vegetation and succession of 25 beaver meadows and ponds using the space-for-time substitution. We used aerial photography to investigate whether a large 1947 fire in one region of Mount Desert Island, Maine, led to differences in regional temporal fluctuations in beaver pond occupancy over 60 y and determined whether these fluctuations led to different regional distributions of beaver wetland plant community types. Cluster analysis segregated 4 wetland groups: sedge meadows, sedge fens, shrub fens, and forested fens, which segregated along gradients of time since dam collapse, water chemistry, and wetland size. Beaver did not affect water chemistry or wetland size. Pond vegetation was a function of community type prior to flooding, water chemistry, and geomorphic setting. The successional model consisted of 2 separate cycles, corresponding to differences in pH and peat accumulations. Beaver pond creation rates differed in burned and unburned regions over time. Due to increased activity in the burned region, there was a different distribution of plant communities between the regions. Wetlands abandoned at the peak of beaver pond creation in 1979 were flooded for shorter durations, resulting in forested fen vegetation.. Beaver activity created different successional cycles within different water chemistry and geomorphic contexts. Water chemistry, wetland size, and initial wetland state, which primarily determined non-forested wetland type, were not influenced by beaver.

In landscapes perturbed by industrial mining, seed dispersal limitations could affect the potential for forest recovery. We measured seed removal in different vegetation layers by different dispersal vectors to examine the potential for natural recovery of a severely stressed forest in Greater Sudbury, Canada. Vegetation structure was measured and causal relationships with seed removal along a stress gradient of past pollution were estimated using path analysis. There was almost no seed removal in the most degraded sites, and birds removed fewer seeds than other animal groups in all sites. An increasing trend across the pollution gradient was identified for both seed types examined (blueberries and oaks), and it was strongly correlated with basal area per hectare, distance to decommissioned smelter, and understory cover. A negative effect of an invasive slug species on the seed consumption process was detected. We show slow recovery in more degraded sites, the importance of forest structure for animal activity, and the need for considering structural and functional components when analyzing regeneration from past pollution.

Dans des paysages perturbés par l'exploitation minière, certaines limites à la dispersion des graines pourraient avoir un effet sur le potentiel de rétablissement de la forêt. Nous avons mesuré le prélèvement de graines par divers vecteurs de dispersion dans différentes couches de végétation pour examiner le potentiel de rétablissement naturel d'une forêt soumise à un stress sévère dans la grande région de Sudbury au Canada. Nous avons évalué la structure végétale et estimé les relations causales avec le prélèvement de graines le long d'un gradient de stress dû à une pollution passée en utilisant une analyse de coefficients de direction. Il n'y avait presque aucun prélèvement de graines dans les sites les plus dégradés, et dans tous les sites, les oiseaux ont prélevé moins de graines que les autres groupes d'animaux. Une tendance vers une augmentation du prélèvement a été observée le long du gradient de diminution de la pollution pour les deux types de graines examinés (bleuets et chênes). Le prélèvement était fortement corrélé avec la surface terrière par hectare, la distance à la fonderie déclassée et la couverture végétale en sous-étage. Un effet négatif d'une espèce envahissante de limace sur la consommation de graines a été détecté. Nous montrons que le rétablissement est lent dans les sites plus dégradés, que la structure forestière est importante pour l'activité animale et qu'il est nécessaire de prendre en considération les composantes structurelles et fonctionnelles lors de l'analyse de la régénération forestière à la suite d'une pollution passée.

Nomenclature: International Commission on Zoological Nomenclature, online; Newmaster & Ragupathy, online.

We used browse history surveys of paper birch (Betula papyrifera) to evaluate the response of snowshoe hare (Lepus americanus) to harvest treatments with 0–70% tree retention in boreal forests of eastern Quebec. The proportion of different birch stem architecture types was used to assess broad changes in browsing pressure following harvesting. We also identified the years in which individual birch stems were browsed by hares to compare probability of stem use over time, from the winter preceding harvesting until 2–3 y after logging. A higher proportion of birch with released-type growth forms in logged stands suggested a reduction in browsing by hare following all types of harvest treatment. Detailed stem analysis revealed, however, that changes in browsing pressure varied considerably among treatments. Hares browsed individual stems with equal probability in all sites prior to harvesting. Probability of stem use declined rapidly in treatments with < 25% tree retention (basal area ≤ 3 m²·ha^-1) relative to uncut forests in the 2–3 y following harvesting. In contrast, birch stems in selection cutting treatments with > 50% tree retention (basal area ≥ 15 m²·ha^-1) remained just as likely to be browsed by hare as those in uncut forests during the same period. Browse history provided a unique opportunity to assess pre-treatment habitat use, even though surveys took place after logging. Selection cutting appears to be a promising avenue for maintaining snowshoe hare habitat that is characteristic of old-growth eastern boreal forests, even over the short term.

The Grande-Plée-Bleue peatland in southern Quebec is the second largest undisturbed ombrotrophic peat bog south of the St. Lawrence River. Macrofossil analysis of 2 sediment cores was performed to reconstruct the developmental stages (flora, trophic stages) of a sector of this ecosystem located in a peri-urban area. Organic accumulation began around 9500 cal. y BP (calibrated years before present) in one or several small, shallow ponds after the retreat of the postglacial Goldthwait Sea. The spatial growth of the peatland took place through paludification to the detriment of a forest that was initially composed of balsam fir and white birch. Ombrotrophic conditions formed very early in the history of the site, around 8300 cal. y BP. Since that time, the bog's vegetation cover (composition, structure) has been quite stable. The longterm dynamics of the peatland was controlled by autogenous factors. However, more humid conditions were present locally between ca 1050 and ca 400 cal. y BP Similar indications have also been found in other bogs of southern Quebec for the same period, which suggests a change in regional hydroclimatic conditions.