2023

Permanent URI for this collectionhttps://hdl.handle.net/1807/126408

Browse

Recent Submissions

Now showing 1 - 20 of 70
  • Item
    The 2023 wildfire season in Québec: an overview of extreme conditions, impacts, lessons learned and considerations for the future
    (Canadian Science Publishing, 2024-04-19) Boulanger, Yan; Arseneault, Dominique; Bélisle, Annie Claude; Bergeron, Yves; Boucher, Jonathan; Boucher, Yan; Danneyrolles, Victor; Erni, Sandy; Gachon, Philippe; Girardin, Martin P.; Grant, Eliane; Grondin, Pierre; Jetté, Jean-Pierre; Labadie, Guillemette; Leblond, Mathieu; Leduc, Alain; Puigdevall, Jesus Pascual; St-Laurent, Martin-Hugues; Tremblay, Junior; Waldron, Kaysandra
    The 2023 wildfire season in Québec set records due to extreme warm and dry conditions, burning 4.5 million hectares and indicating persistent and escalating impacts associated with climate change. This study reviews the unusual weather conditions that led to the fires, discussing their extensive impacts on the forest sector, fire management, boreal caribou habitats, and particularly the profound effects on First Nation communities. The wildfires led to significant declines in forest productivity and timber supply, overwhelming fire management resources, and necessitating widespread evacuations. First Nation territories were dramatically altered, facing severe air quality issues and disruptions. While caribou impacts were modest across the province, the broader ecological, economical, and social repercussions were considerable. To mitigate future extreme wildfire seasons, the study suggests changes in forest management practices to increase forest resilience and resistance, adapting industrial structures to changes in wood type harvested, and enhancing fire suppression and risk management strategies. It calls for a comprehensive, unified approach to risk management that incorporates the lessons learned from the 2023 fire season and accounts for ongoing climate change. The studyunderscores the urgent need for detailed planning and proactive measures to reduce the growing risks and impacts of wildfires in a changing climate.
  • Item
    Environmental, social, and economic challenges to forest-based micro-entrepreneurship: A comparative case study in Finland
    (Canadian Science Publishing, 2024-06-06) Luhas, Jukka; Mikkilä, Mirja
    Countries worldwide, especially Nordic countries, have proposed a forest-based bioeconomy to halt systemic risks, such as climate change, and to create socioeconomic welfare. Entrepreneurs operating in various business sectors and regions face several complex challenges in this regard. However, the challenges faced by forest-based micro-entrepreneurs have not been addressed across various regions using systems thinking. This comparative case study aimed to identify the environmental, social, and economic challenges faced by forest-based micro-entrepreneurs and the spatial features of these challenges—their scale, interactions, and prevalence—in two different regions in Finland: Lapland and South Karelia. These regions’ economies rely heavily on the recreational value of nature and on the large-scale pulp and paper industries, respectively. Semi-structured interviews were conducted with micro-entrepreneurs from various sectors, such as forestry, logging, tourism, and natural products. The data were analyzed using qualitative content analysis. The framework used enabled a deeper spatial understanding of the challenges experienced by forest-based micro-entrepreneurs. The micro-entrepreneurs in the two case regions had great similarities in terms of themes related to trust, workload, and labor shortage. This may hinder the implementation of new practices in regional forest-based bioeconomy development. Future quantitative studies could validate the identified challenges for further policy development.
  • Item
    Effect of three-year amendment measures on coastal saline-alkali soil conditions during the growing season
    (Canadian Science Publishing, 2024-05-30) Jia, Zhaohui; Zhu, Lingjun; Shi, Yuxuan; Liu, Jing; Zeng, Jingyi; Ma, Shilin; Li, Chong; Wu, Yingkang; Leng, Huimei; Liu, Xin; Zhang, Jinchi
    Seawater intrusion and fluctuations in the water table in coastal areas lead to seasonal variations in soil salinity and pH, which greatly limit the development of coastal protection forests. In a three-year field study, the impact of five soil amendment measures were evaluated on soil conditions in coastal areas. Amendments included biochar, biochar with arbuscular mycorrhizal fungi (AMF), straw with AMF, straw alone, and AMF alone, compared to a control (CK) with no additive. Results indicated that combinations of straw, biochar, and AMF reduced soil pH across various layers and seasons, with electrical conductivity mainly decreasing in spring. During the summer, at the 0-20 cm soil depth, microbial biomass carbon notably increased due to these mixtures. Additionally, AMF alone and biochar with AMF significantly improved enzyme activities in the 0-40 cm layer in spring, while in fall, AMF alone notably increased nutrient availability in the same layer. Linear regression analysis revealed a negative correlation between electrical conductivity, microbial biomass carbon, enzyme activity, and nutrient availability with pH. The biochar–AMF mixture emerged as the most effective soil amendment, suggesting that using it in conjunction with seasonal management could optimize soil health and promote silviculture in coastal regions.
  • Item
    Drought-induced growth phenotypes are associated with genetic variation across a white pine hybrid zone.
    (Canadian Science Publishing, 2023-12-06) Peach , Lulu Rosemary; Waring, Kristen M.; Fulé, Peter Z.; Eckert, Andrew J.; Menon, Mitra; Swenson, Jared
    Understanding relationships among warming climate, increased drought severity, and the genetic architecture of hybrid drought resilience is necessary for forest conservation and management. We calculated three drought-related tree-ring-growth indices (dendrophenotypes) using tree-ring data from hybrid P. strobiformis – P. flexilis study trees at nine sites across Colorado, New Mexico, Arizona, and Texas. Along with hybrid index (percentage of P. strobiformis ancestry inherited by a single tree), and climate variables, we used dendrophenotypes to (Q1) examine relationships among climate and hybrid index, (Q2) examine relationships between dendrophenotypes and hybrid index, and (Q3) conduct a genotype-phenotype analysis. We observed significant correlation between hybrid index and dendrophenotypes resulting from high-temperature drought in addition to significant correlation between those dendrophenotypes and our dataset of single-nucleotide polymorphisms (SNPs). We conclude that P. strobiformis – P. flexilis trees exhibiting higher hybrid indices are more resilient to high-temperature drought events and encourage future research that identifies genetic linkage between relevant loci and their conferred physiological benefits.
  • Item
    Can partial-cut harvesting be used to extend the availability of terrestrial forage lichens in late-seral pine-lichen woodlands? Evidence from the Lewes Marsh (southern Yukon) silvicultural systems trial.
    (Canadian Science Publishing, 2023-12-15) Coxson, Darwyn; Sharples, Robin
    In northern British Columbia and southern Yukon woodland caribou forage extensively on terrestrial lichens, predominately mat-forming Cladina species in late-successional pine-lichen woodlands. Many of these stands are now reaching a point in their development where lichen abundance declines as feather-moss mats increase. We evaluated the response of forest floor plant communities in pine-lichen woodlands from the southern Yukon Lewes Marsh partial-cutting trial eight years after harvesting. Photoplot results documented a major decline (>60% ± 5.6% S.E.) in the mean surface area of existing large clumps of C. mitis in control (unharvested) treatments, whereas mean surface area of large C. mitis clumps declined by 28% (± 15% S.E.) in the one-third basal-area removal, and showed an increase of 13.5% (± 25% S.E.) in the two-third’s basal-area removal. Line-intercept transects documented no changes in overall stand-level lichen abundance between pre- (2012) and post-harvest (2021) measurements, while feather-moss mats and dwarf shrubs showed declines and increases respectively in partial-cutting harvest plots. Stand thinning may provide a bridging strategy to extend the period of forage lichen availability in late-seral pine-lichen woodlands, an important consideration in landscapes where increasing severity and frequency of fires is changing the seral-state distribution of caribou habitat.
  • Item
    Tree and stand characteristics associated with the occurrence of false heartwood in individual Japanese white birch trees
    (Canadian Science Publishing, 2023-12-24) Nakaya, Akira; Osaki, Hisashi; Ohno, Yasuyuki; Yoshida, Toshiya
    New wood uses of Japanese white birch (Betula platyphylla var. japonica) have attracted much attention in recent years, but false heartwood has led to a decline in commercial value due to its irregular wood color. In this study, we assessed the occurrence of false heartwood and its proportion to stem cross-sectional area (PFH) in individual Japanese white birch (482 trees) in a ca. 70-year-old natural secondary forest. Specifically, we investigated the relative strength of the direct/indirect effects of individual size (BA), growth rate (GR), crown ratio (CR), number of branch scars (NBS), basal area sum of neighboring trees (BAS) and topographic wetness index (TWI) on PFH. In total, 80.3% of trees had false heartwood. CR was found to be the most important factor, acting through direct and indirect negative effects. BA and NBS had a positive effect, and TWI had a negative effect on PFH. BA had a positive correlation with tree age, indicating that PFH can be reduced in trees with faster growth. Simultaneously, BAS had an indirect positive effect on PFH. These results suggested that thinning, which reduces BAS and increases CR, can reduce false heartwood.
  • Item
    Growth responses to thinning from below in uneven-aged interior Douglas-fir dominated stands.
    (Canadian Science Publishing, 2023-11-13) Acquah, Stella Britwum; Marshall, Peter L.; Eskelson, Bianca N.I.; Moss, Ian S; Barbeito, Ignacio
    We assessed the impacts of three approaches to thinning from below with varying spatial patterns on several stand and individual tree variables for interior Douglas-fir (Pseudotsuga menziesii var. glauca (Beissn.) Franco), interior spruce (Picea glauca [Moench] Voss × Picea engelmannii Engelm.), and lodgepole pine (Pinus contorta Dougl. Ex Loud. var. latifolia Englem.) in central British Columbia, Canada. The three thinning treatments were two experimental “clumped” treatments (3 m Clumped and 5 m Clumped) and the Standard (more uniform spacing) thinning treatment that was employed operationally at that time. We used long-term data from 24 plots measured five times over 21 years. Thinning increased stand basal area increment, with the plots that received the 5 m Clumped treatment having significantly higher periodic annual relative basal area increment than the unthinned Control plots. The responses for the two clumped treatments were not any lower than the Standard. The 3 m Clumped treatment was best if one is concerned about fast recovery of the growing space; however, the 5 m Clumped spacing treatment may be preferable if higher individual tree vigour is needed for resistance and resilience to fire, insects, and disease.
  • Item
    Modelling diameter at breast height distribution of jack pine and black spruce natural stands in eastern Canada
    (Canadian Science Publishing, 2023-12-19) Rijal, Baburam; Sharma, Mahadev
    Individual tree diameter at breast height (DBH) distribution is an important information for forest management planning. Forest managers obtain the DBH data either by field measurements or estimations using predictive models. However, probability distribution models are still lacking or need improvement. Therefore, we aimed to construct and fit diameter distribution models that reflect forest structure and composition change. We evaluated gamma, log-normal, and Weibull probability distribution functions (PDFs) for two commercially important tree species, black spruce (Picea mariana (Mill) B.S.P.) and jack pine (Pinus banksiana Lamb), grown in natural stands across Ontario, Canada. We modelled the parameters of the distributions as a function of stand-level variables for these species. We used DBH data from 735 permanent sample plots. Our results showed that all three evaluated PDFs reflected observed DBH distribution. We demonstrated that the moment-based recovered parameters could represent the maximum likelihood-estimated parameters precisely, and parameters of the PDFs can be modelled as a function of stand-level dynamic covariates. The models unbiasedly predicted the PDF parameters DBH means and DBH classes. The R2 of the model fit ranged between 0.35 and 0.98 for the predicted parameters and 0.90 and 0.97 for the predicted DBH.
  • Item
    How do different thinning methods influence spatial tree diversity in mixed forest stands of planted Norway spruce (Picea abies L.) and naturally regenerated birch (Betula spp.) in Southern Sweden?
    (Canadian Science Publishing, 2023-11-02) Becs, Artis; Bergström, Dan; Egnell, Gustaf; Pommerening, Arne
    Forest biomass has become a viable alternative energy source for replacing fossil fuels, particularly after the European Union acknowledged its sustainability status. In order to reach zero net greenhouse gas emissions by 2045 in Sweden, new efficient methods of biomass extraction, such as geometrical biomass thinnings, are being explored and tested. These machine-based methods involve the extraction of above-ground biomass in narrow 1-2 m-wide strips between extraction racks. While evidence-based optimization of biomass extraction mostly focuses on time- and cost-efficiency and on stand growth, criteria such as tree diversity are often overlooked. However, with ongoing climate change tree diversity is crucial to strengthening the resilience and productivity of future forests, which also enhance the provision of ecosystem services, and overall biological diversity. Therefore, we studied the effects of different biomass thinning strategies on spatial tree diversity in Southern Sweden using nearest-neighbour summary statistics. We found scientific evidence that different geometrical designs of biomass thinning, especially in 1 or 2 m-wide strips, resulted in higher spatial tree diversity compared to conventional biomass thinning. Hence, in mixed conifer-broadleaved forests, biomass thinning in 1 or 2 m-wide strips is recommended for maintaining spatial tree diversity.
  • Item
    Response of Moose to Forest Harvest and Management: A Literature Review
    (Canadian Science Publishing, 2023-10-20) Johnson, C.; Rea, Roy
    Moose are an iconic symbol of northern forests. In many jurisdictions, the management of moose has focused on regulating harvest with less emphasis on understanding moose-habitat relationships. We reviewed the literature and summarised the effects of forest harvest and management on the ecology of moose. Greater than 40 years of scientific studies document both positive and negative effects of forest harvest and associated activities such as silviculture and road building. Moose require spatially adjacent patches of younger plant communities for forage and older forests for thermal and security cover. Extensive and rapid forest harvest can result in the prevalence of young forest with a corresponding reduction in the fitness of moose populations. A warming climate likely will exacerbate the negative effects associated with the broad-scale removal of forest cover. Resource roads can create edge habitat that may serve as forage, but those features result in increased hunting and collisions with vehicles and facilitate the movement of predators. Post-harvest silviculture, including the application of herbicides, can create stand conditions that provide very little or low-quality forage. The ecological and societal benefits of moose are dependent on forest management that provides a mix of old and young forest, employs silviculture that retains adequate cover and forage plants, and minimises the development of roads.
  • Item
    Rodent-mediated seed limitation affects woody seedling establishment more than invasive shrubs and downed woody debris
    (Canadian Science Publishing, 2023-10-15) Connolly, Brian; Zirbel, Chad; Orrock, John L.
    Seedling establishment is crucial for the development of self-regenerating tree populations. Determinants of tree establishment vary widely and may compound in their effects. Using a factorial experiment, we manipulated invasive shrubs, downed woody debris (DWD), and rodent access to evaluate factors limiting the establishment of six woody species (five native trees, one invasive shrub). Our results suggest these factors independently contribute to tree seedling establishment. Exclusion of rodents increased establishment three-fold. Invasive shrub removal (Elaeagnus umbellate; Lonicera maackii) and the presence of DWD promoted establishment of two native trees (Pinus strobus; Sassafras albidum). Notably, the presence of DWD halved L. maackii establishment. In identifying rodents as drivers of seed limitation, our results support findings that seed additions will likely promote woody seedling establishment when rodents are not abundant (e.g., low populations) or when seeds are physically or chemically protected (e.g., via taste deterrents). Management plans vary in DWD retention; results from our experimental cohort indicate retaining or introducing DWD promotes native tree recruitment and limits invasive shrub establishment. Future studies exploring the species-specific effects of invasive shrub removal and DWD amendments across multiple cohorts will help determine which woody species benefit most from these management practices.
  • Item
    Landscape-level likelihood estimation of eastern spruce dwarf mistletoe (Arceuthobium pusillum) infestations in lowland black spruce (Picea mariana) forests of Minnesota, USA
    (Canadian Science Publishing, 2023-10-03) Gray, Ella R; Russell, Matthew B.; Windmuller-Campione, Marcella Anna
    Biotic disturbance agents are important factors influencing forest dynamics; incorporating them into management planning requires detailed understanding of their distribution, prevalence, and effects on stand dynamics. However, this information can be difficult to collect in remote forest systems, such as lowland black spruce (Picea mariana (Mill.) B. S. P.) forests affected by eastern spruce dwarf mistletoe (Arceuthobium pusillum Peck, hereafter ESDM). In such cases, predictive modeling is often needed to inform management decisions and address forest health questions. Here, we used two publicly available datasets to predict areas where black spruce is more likely to be infested with ESDM in northeastern Minnesota, USA. Using random forest modeling and logistic regression, we found location, stand age, basal area, site index, average diameter, and metrics of species composition to be among the most important predictors of ESDM occurrence. Predictions showed two regions of greater likelihood of infestation with distinct ecological characteristics and ownership patterns. By understanding how stand structural characteristics relate to ESDM infestations, managers can improve monitoring and management of ESDM at the stand and landscape scales. Additionally, our approach of using multiple datasets and modeling methods can serve as a framework for decision making for other forest health concerns.
  • Item
    Biomass accumulation in trees and downed wood in northern hardwood forests: repeated measures of a successional chronosequence in New Hampshire, USA
    (Canadian Science Publishing, 2023-10-11) Nash, Joseph M; Vadeboncoeur, Matthew; McGee, Gregory G.; Woodall, Christopher W.; Yanai, Ruth D.
    Successional, second-growth forests dominate much of eastern North America, thus patterns of biomass accumulation in standing trees and downed wood are of great interest for forest management and carbon accounting. The timing and magnitude of biomass accumulation in later stages of forest development are not fully understood. We applied a “chronosequence with resampling” approach to characterize live and dead biomass accumulation in sixteen northern hardwood stands in the White Mountains of New Hampshire. Live aboveground biomass increased rapidly and leveled off at about 350 Mg/ha by 145 years. Downed wood biomass fluctuated between 10 and 35 Mg/ha depending on disturbances. The species composition of downed wood varied predictably with overstory succession, and total mass of downed wood increased with stand age and the concomitant production of larger material. Fine woody debris peaked at 30-50 years during the self-thinning of early-successional species, notably pin cherry. Our data support a model of northern hardwood forest development wherein live tree biomass accumulates asymptotically and begins to level off at ~140-150 years. Still, 145-year-old second-growth stands differed from old-growth forests in their live (p = 0.09) and downed tree diameter distributions (p = 0.06). These patterns of forest biomass accumulation would be difficult to detect without a time series of repeated measurements of stands of different ages.
  • Item
    GENOTYPE AND ENVIRONMENTAL INTERACTION ON THE WOOD QUALITY OF Eucalyptus spp. FOR ENERGY PURPOSES
    (Canadian Science Publishing, 2023-09-27) da Cunha, Thammi Queuri Gomes; Lima, Pedro Augusto Fonseca; Santos, Alyne Chaveiro; Novaes, Evandro; Sette Jr, Carlos Roberto
    The objective of this study was to evaluate the wood chemical and energetic characteristics of Eucalyptus spp. clones planted in three sites in the Midwest of Brazil. Thus, five clones from Eucalyptus spp. were planted in different sites aiming to determine the qualitative characteristics of the wood resulting from the variation in the tree growth environment and the genetic material. The same clones was planted in the three sites to determine the genotype x environment interaction. The trees were then sampled at five years after planting for their physical-chemical and energetic characterization. The results showed that the wood characteristics vary in different proportions according to the clone, just as the growth environment of the trees alters the behavior of the clones for the same characteristics. The edaphic variables affected the wood characteristics, inferring that the water content in the soil has more effect on the wood properties than the water content in the air, mainly on wood basic density. The results of this study indicate that using the appropriate genotype related to the environment conditions determines the wood characteristics, since the wood properties are strongly influenced by the edaphoclimatic variables.
  • Item
    How consistent are citizen science data sources, an exploratory study using free automated image recognition apps for woody plant identification
    (Canadian Science Publishing, 2023-09-08) Anyomi, Kenneth A.
    Rapid advances in artificial intelligence have led to an upsurge in automated image recognition phone apps. This has increased public involvement in the collection, identification (ID) and analysis of biological data. While this is good for the field of biological data monitoring, it is not clear how consistent IDs are from different apps. The goal of this exploratory work is to verify the accuracy and consistency in plant species identification from two widely used and free apps i.e. PlantNet and iNaturalist app. This work was conducted by scanning leaf samples along Bruce trail in the Niagara Escarpment Biosphere reserve and the Royal Botanical Gardens arboretum, in Hamilton Ontario. Results show over 90% consistency in the identification of woody plants at the level of genus. At the species level, PlantNet app demonstrated 79% accuracy (i.e. 79 out of 100 species correctly identified) while the iNaturalist app demonstrated 44% accuracy. Enhancing species representation in the database for southern Ontario might help particularly species in the family Betulaceae, Rosaceae and Pinaceae. Complementary use of the apps is recommended as a cautionary measure to reduce the likelihood of error in species-level woody plant identification as well as using apps in conjunction with field guide.
  • Item
    Overview of the 2022 North American Forest Ecology Workshop (NAFEW): Turning Ecological Answers into Forest Management Actions
    (Canadian Science Publishing, 2023-09-25) Venier, Lisa; Morris, Dave M.; Work, Timothy
    Overview of the 2022 North American Forest Ecology Workshop (NAFEW): Turning Ecological Answers into Forest Management Actions
  • Item
    Combined application of organic manure and reduced-rate chemical fertilizer improved growth, nutrient use efficiency, biomass accumulation, and carbon sequestration of Zanthoxylum armatum seedlings
    (Canadian Science Publishing, 2023-08-16) SABA, TAHSEEN; Saleem, Fariha; Liu, Wanlin; Wang, Jingyan; Hui, Wenkai; Nazir, Hafsa; Gong, Wei
    The possibility of incorporating organic manure (OM) to reduced rates of chemical fertilizers (CF) to augment biomass production and carbon sequestration (Cseq), and the role of nitrogen (N), phosphorus (P) and potassium (K) uptake in vegetation Cseq was investigated through pot experiment with one-year-old Zanthoxylum armatum seedlings. Seven treatments were designed including NPK, PK, NP, NK, OM, MNPK (50%NPK+50%OM), and control (CK, no fertilization). MNPK application improved nutrient uptake of 2.76-fold N, 3.34-fold P, and 2.01-fold K, resulting in the highest biomass production and biomass Cseq (1.65-fold) as compared to CK. Correlation and redundancy analysis revealed that Cseq is significantly associated to biomass production (r = 0.994) and regulated by N and P uptake. The highest NUE was recorded for N (38.8%), followed by K (21.1%), and P (16.4%) under MNPK application. Therefore, MNPK could be an optimum measure regarding fertilizer saving, biomass production and attaining C neutrality.
  • Item
    Nesting-Tree Preferences of the Black Woodpecker - the Biggest Cavity Excavator in in a Conifer-Dominated Forests in Poland
    (Canadian Science Publishing, 2023-09-03) Zawadzki, Grzegorz
    The black woodpecker Dryocopus martius is an ecologically disproportionately important forest species owing to its abundance. Its large cavities provide breeding sites and shelter for many species - large birds, mammals, and social insects. I evaluated the nest tree preferences of black woodpeckers in the Augustów Forest, northeast Poland. Approximately 400 black woodpecker cavities were observed. The Scots pine, Pinus sylvestris, was the most commonly selected tree species, accounting for 90%. The cavity trees were 55–225 years old. All trees younger than 90 years were broad-leaved tree species. The trees used to excavate the cavities had a larger diameter at the breast height (DBH) than the average of the stand. The trees selected by black woodpeckers were significantly shorter than the average height of the stands. Over 60% of the cavities were excavated 10–16 m above ground level. I found that the diameter at breast height and the first branch height were critical factors affecting the cavity entrance height. In pine-dominated forests, black woodpeckers preferred dead trees. Approximately 44% of new cavities were excavated from dead trees. Leaving dead or dying large trees in commercial forests benefits black woodpeckers and large secondary cavity nesters that depend on it and promotes biodiversity conservation. Birds excavate new cavities at a high rate yearly, in contrast with beech-dominated forests.
  • Item
    Local adaptation of balsam fir seedlings improves growth resilience to heat stress
    (Canadian Science Publishing, 2023-09-14) Ravn, Jacob; Taylor, Anthony Robert; Lavigne, Michael B.; D'Orangeville, Loïc
    Increasing frequencies of heat waves and drought are expected to shift the range and growth of balsam fir (Abies balsamea (L.) Mill.), a widely distributed cold-adapted boreal species. However, our ability to predict this species response to these climate anomalies remains limited, especially when considering how trees can exhibit delayed and persistant growth responses to these stressors, or legacy effects. Here, we assess the growth response of balsam fir seedlings from four populations following 60 treatment combinations of temperature and water deficit in the previous year. Although we observed moderate water deficit legacy effects on growth, there were no resilience or recovery responses. We did, however, observe considerable negative legacy effects on growth proportional to the level of warming, with average legacy growth declines reaching 45% under the highest warming treatment. Furthermore, the southern populations displayed a 28% higher average growth resilience to temperature stress compared to the northern populations, indicating a higher tolerance to warming. When comparing legacy effects on balsam fir populations at moderate warming conditions relative to current local baseline climate, we report limited growth declines for southern populations and growth increases for the northern populations. While our results highlight the importance of legacy effects from heat stress in seedlings, they also provide evidence that careful selection of warm-adapted genotypes for reforestation efforts may help offset some of these legacy effects.
  • Item
    Seed coatings containing capsaicin reduce seed removal on temperate woody species
    (Canadian Science Publishing, 2023-08-12) Lanni, Francesca; Connolly, Brian; Orrock, John L.; Guiden, Peter
    Coating seeds in taste-averting chemical defenses (e.g., capsaicin from Capsicum spp.) can reduce rodent seed predation, and thus might promote plant establishment and forest regeneration. However, the efficacy of such seed coatings remains unknown for many woody plant species, and seed coatings have not been evaluated across different habitats where forest managers might seek to promote forest regeneration. We used two complementary seed-removal experiments in closed-canopy forests (Michigan) and an old field undergoing reforestation (New York) to examine whether coating seeds of four native tree species (Acer rubrum, Fagus grandifolia, Pinus banksiana, Pinus resinosa) with chili powder reduces seed predation by rodents. In all species and habitats, untreated control seeds were removed more than seeds treated with capsaicin (94% more in the closed-canopy forest, 17% more in the old field). Seed coatings containing capsaicin may provide a generally effective tool to support native tree recruitment and promote restoration success.