Forest Ecology and Management最新文献

{"title":"Thinning with follow-up burning treatments have increased effectiveness at reducing severity in California's largest wildfire","authors":"Kristen L. Shive ,&nbsp;Michelle Coppoletta ,&nbsp;Rebecca Bewley Wayman ,&nbsp;Alison K. Paulson ,&nbsp;Kristen N. Wilson ,&nbsp;John T. Abatzaglou ,&nbsp;Saba J. Saberi ,&nbsp;Becky Estes ,&nbsp;Hugh D. Safford","doi":"10.1016/j.foreco.2024.122171","DOIUrl":"10.1016/j.foreco.2024.122171","url":null,"abstract":"<div><div>In historically frequent-fire forests of the western US there has been an increase in stand-replacing wildfire that is well outside of the historical range of variability (HRV), leading to forest loss at unprecedented scales. As a result, forest managers are increasingly applying forest management treatments designed to reduce the probability of stand-replacing wildfire, by reducing the tree densities and woody debris that have accumulated after more than a century of fire exclusion. Although these treatments have generally been shown to be effective, increasingly warm and dry conditions may challenge the efficacy of these treatments. We compared fire severity (% basal area mortality) in areas that had mechanical thinning with a follow up fire treatment (broadcast burning or pile burning), mechanical thinning without a follow up fire treatment, and untreated areas in California’s largest wildfire to date, the 2021 Dixie Fire. We found that the probability of stand-replacing wildfire (defined here as 100 % basal area mortality) was highest on large fire growth days, and lowest in areas that were treated with mechanical thinning and fire; mechanical thinning treatments with no follow up fire treatment did not differ from untreated areas. Where stand-replacing wildfire did not occur, percent basal area mortality was reduced in both the mechanical plus fire treatment and the mechanical-only treatment, both of which were characterized by larger trees and lower densities. This suggests that the addition of the fire treatment is critical for reducing fire severity under more extreme burning conditions, but that the mechanical-only treatments can still be effective under milder burning conditions. We also found that the majority (93 %) of our treated plots were within the HRV for tree density prefire. Postfire, 79 % of the plots with a mechanical thinning plus fire treatment remained within HRV target conditions. In contrast, 48 % of the mechanical thinning only plots, and 58 % of untreated plots, had no live trees. This work contributes to a growing body of evidence that forest treatments to reduce both tree densities and surface fuels are critical for reducing fire severity and forest loss.</div></div>","PeriodicalId":12350,"journal":{"name":"Forest Ecology and Management","volume":"572 ","pages":"Article 122171"},"PeriodicalIF":3.7,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142424020","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Response of understory vegetation to long-term occupancy by introduced Pinus species in temperate deciduous hardwood forests","authors":"Patrick J. Duffy ,&nbsp;Douglass F. Jacobs ,&nbsp;John M. Kabrick ,&nbsp;Christopher D. Thornton ,&nbsp;J. Travis Swaim ,&nbsp;Michael A. Jenkins","doi":"10.1016/j.foreco.2024.122310","DOIUrl":"10.1016/j.foreco.2024.122310","url":null,"abstract":"&lt;div&gt;&lt;div&gt;In many temperate regions of the world, conifer species have been planted to stabilize soils and promote site recovery on former hardwood sites that were cleared for agriculture. In many areas of eastern North America, these conifer plantings consisted of introduced (non-native) &lt;em&gt;Pinus&lt;/em&gt; species planted on abandoned agricultural land once dominated by mesophytic hardwood species. These plantings constitute a shift in overstory composition away from native hardwood species with nutrient-rich litter that decomposes more quickly towards &lt;em&gt;Pinus&lt;/em&gt; species with recalcitrant litter that may alter soil chemistry and nutrient availability. To examine how edaphic conditions associated with long-term introduced &lt;em&gt;Pinus&lt;/em&gt; species occupancy are related to forest regeneration and herbaceous-layer diversity and composition, we sampled a total of 97 plots in planted &lt;em&gt;Pinus echinata&lt;/em&gt; and &lt;em&gt;Pinus strobus&lt;/em&gt; stands and naturally regenerated hardwood stands growing on two ecological landtype phases (ELTPs) of southern Indiana, USA forests, &lt;em&gt;Fagus-Acer saccharum/Arisaema&lt;/em&gt; Mesic Ridges, and &lt;em&gt;Acer saccharinum/Boehmeria&lt;/em&gt; Bottomlands. We collected vegetation data and analyzed soil samples to examine herbaceous-layer species distribution across gradients using non-metric multidimensional scaling (NMS) ordination. Two-way ANOVA was used to examine differences in individual species and species functional groups across stand types (&lt;em&gt;P. echinata&lt;/em&gt;, &lt;em&gt;P. strobus&lt;/em&gt;, and native hardwoods) and ELTPs. Our results show that differences in soil chemistry resulting from &lt;em&gt;Pinus&lt;/em&gt; spp. occupancy were associated with differences in the composition and distribution of herbaceous-layer species in ordination space. Species across stand types and ELTPs were distributed across dominant gradients related to litter depth, cation exchange capacity, cation content, and soil aluminum concentration. Hardwood sites had significantly greater herbaceous-layer cover (139.6 ± 8.0 %) than &lt;em&gt;P. echinata&lt;/em&gt; (48.5 ± 6.2 %) or &lt;em&gt;P. strobus&lt;/em&gt; sites (81.7 ± 7.7 %), as well as greater herbaceous-layer species richness and diversity (mean species richness was 46.9 ± 2.1 on hardwood stands vs. 33.3 ± 1.6 and 36.4 ± 2.0 on &lt;em&gt;P. echinata&lt;/em&gt; and &lt;em&gt;P. strobus&lt;/em&gt; stands, respectively). &lt;em&gt;Pinus echinata&lt;/em&gt; stands contained a greater density of woody regeneration, including &lt;em&gt;Quercus&lt;/em&gt; spp. (201 ± 48 saplings ha&lt;sup&gt;−1&lt;/sup&gt;) and &lt;em&gt;Fagus grandifolia&lt;/em&gt; stems (415 ± 82 saplings ha&lt;sup&gt;−1&lt;/sup&gt;), both of which occurred in greater density than &lt;em&gt;Acer saccharum&lt;/em&gt; (163 ± 93 saplings ha&lt;sup&gt;−1&lt;/sup&gt;) and &lt;em&gt;A. rubrum&lt;/em&gt; (70 ± 64 saplings ha&lt;sup&gt;−1&lt;/sup&gt;). Our results suggest that pine occupancy has created divergent successional trajectories in comparison to hardwood stands. These differing trajectories may offer both challenges and opportunities for restoration efforts. For example, the greater abundance of &lt;em&gt;Quercus","PeriodicalId":12350,"journal":{"name":"Forest Ecology and Management","volume":"572 ","pages":"Article 122310"},"PeriodicalIF":3.7,"publicationDate":"2024-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142357852","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Navigating neighborhoods: Density, size, and species diversity influences on tree survival in subtropical secondary forests","authors":"Haonan Zhang ,&nbsp;Fei Lu ,&nbsp;Xiao Zheng ,&nbsp;Jianing Xu ,&nbsp;Yanyan Ni ,&nbsp;Shuifei Chen ,&nbsp;Xiaomin Ge ,&nbsp;Yanming Fang ,&nbsp;Yao Li ,&nbsp;Ye Peng ,&nbsp;Hui Ding","doi":"10.1016/j.foreco.2024.122311","DOIUrl":"10.1016/j.foreco.2024.122311","url":null,"abstract":"<div><div>Neighborhood effects significantly impact individual tree survival through mechanisms of resource competition and species interactions within forest ecosystems. However, the specific impacts of these effects, particularly how biodiversity feedback affects survival across diverse life stages and spatial scales in subtropical secondary forests, remains insufficiently documented. To bridge this gap, we conducted an extensive analysis of neighborhood effects at different life stages and spatial scales in the subtropical secondary forests of the Wuyi Mountains in Southeast China, uncovering key insights into the community structure and dynamics. Our investigation over a five-year period encompassed all individuals within our study plot, quantifying effects of neighborhood density, individual size in resource competition, and species diversity in the neighborhood across various life stages. Employing mixed-effects models, we established quantitative relationships to assess the impact of these factors on tree survival at different spatial scales. Our findings confirmed that density dependence adversely affects sapling survival at smaller scales. As trees mature and spatial test scales expand, the detrimental effects of conspecific resource competition on individual mortality decrease, whereas heterospecific resource competition notably impairs survival probabilities in later successional stages, suggesting a shift from intraspecific to interspecific competition as the dominant influence on mortality during secondary succession. Additionally, we detected consistent patterns in conspecific and heterospecific density effects with increasing spatial scale. These effects transitioned from interspecific differences at smaller scales to more uniform positive effects at larger scales, which may be attributed to the strong spatial dependency of neighborhood density effects, potentially due to increased habitat heterogeneity. Furthermore, our study highlights the crucial role of heterospecific neighborhood effects in enhancing survival. We observed significant positive impacts of species diversity and heterospecific interactions on individual tree survival, particularly at smaller spatial scales during the sapling stage. Importantly, our research unveils significant variability in species sensitivity to different neighborhood effects, which change with life stage and spatial scale. This underscores the necessity of accounting for life stage variations among species and the influence of spatial heterogeneity on neighborhood effects such as density. Our findings delineate distinct competition mechanisms between the earlier and later phases of forest succession, emphasizing the distinctive recovery processes of subtropical secondary forests. These insights are essential for informing forest management and conservation strategies, ensuring a nuanced understanding of forest community dynamics.</div></div>","PeriodicalId":12350,"journal":{"name":"Forest Ecology and Management","volume":"572 ","pages":"Article 122311"},"PeriodicalIF":3.7,"publicationDate":"2024-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142357853","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Site conditions rather than provenance drive tree growth, climate sensitivity and drought responses in European beech in Germany","authors":"Lucrezia Unterholzner ,&nbsp;Juliane Stolz ,&nbsp;Marieke van der Maaten-Theunissen ,&nbsp;Katharina Liepe ,&nbsp;Ernst van der Maaten","doi":"10.1016/j.foreco.2024.122308","DOIUrl":"10.1016/j.foreco.2024.122308","url":null,"abstract":"<div><div>Ongoing climate change and associated extreme events strongly impact the growth and vitality of forest ecosystems in Europe. Because of its’ high drought sensitivity, European beech, which is considered as climax tree species in large parts of Central Europe, may specifically suffer. Hence, recent studies increasingly focus on the resistance and resilience of beech growth to climate change. Intra-specific variations in growth responses by comparing different beech provenances, however, received less attention, as did the question whether provenance selection can be used to mitigate potential future negative impacts of climate change. Therefore, we here investigated 24 provenances belonging to the International Beech Provenance Trial growing at three sites in Germany along a latitudinal gradient (study sites are referred to as ’North’, ‘Center’, ‘South’). Specifically, we compared tree-ring width (TRW), diameter breast height (DBH), climate-growth relationships, as well as drought resistance and resilience in the extreme years 2003 and 2018. Large differences in growth performance were observed between the three study sites. At site North, beech trees showed the highest DBH and TRW. Tree growth was predominantly driven by previous-year October and current-year winter temperature, whereas growth at sites Center and South was significantly impacted by summer SPEI and constrained by precipitation in late winter and early June, respectively. Overall, drought responses in 2003 were less variable than in 2018. We found increasing resistance and decreasing resilience from the wetter North to the drier South, but with minimal differences between the Center and the South. Whereas differences between study sites were large, provenance differentiation within sites was comparably low, substantiating that beech is a highly plastic tree species. Even though some provenances were found to perform slightly better or worse, differences were not statistically significant and show unclear patterns. Hence, we conclude that climate change will affect beech forests in Europe mainly depending upon site conditions, and that provenance selection may not ensure superior growth performance.</div></div>","PeriodicalId":12350,"journal":{"name":"Forest Ecology and Management","volume":"572 ","pages":"Article 122308"},"PeriodicalIF":3.7,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142327672","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Historical pyrodiversity in Douglas-fir forests of the southern Cascades of Oregon, USA","authors":"A.G. Merschel ,&nbsp;M.A. Krawchuk ,&nbsp;J.D. Johnston ,&nbsp;T.A. Spies","doi":"10.1016/j.foreco.2024.122306","DOIUrl":"10.1016/j.foreco.2024.122306","url":null,"abstract":"<div><div>Our understanding of forest dynamics and successional pathways in coastal Douglas-fir (<em>Pseudotsuga menziesii var menziesii</em>) forests with relatively frequent mixed-severity fires is limited by a lack of annually precise dendroecological reconstructions that combine records of historical fires and tree establishment. The processes by which old-forest heterogeneity developed under historical fire regimes with recurrent low- and moderate-severity fires has not been well studied at fine temporal scales and across spatial scales. We developed crossdated multi-century records of fire and tree establishment histories in old forests (170 – 550 years) at 34 plots distributed across six sites. Study sites include warm-dry to cool-moist Douglas-fir forest types found in the southern west Cascades of Oregon, USA. Spatial variability in historical fire frequency and fire effects resulted in tremendous diversity in forest developmental histories, age structure, and forest conditions. Most historical fire intervals were very frequent (&lt;10 years) to frequent (&lt;25 years) in dry Douglas-fir forests. Exceptionally high fire frequency and an abrupt decrease in fire frequency after European colonization in dry Douglas-fir forests adds to growing evidence and recognition of Indigenous fire stewardship in montane Douglas-fir forests. In moist forests where Douglas-fir is seral to western hemlock, fire intervals were frequent to moderately frequent (&lt;50 years), but intervals varied substantially over time. Relatively young moist forests burned frequently while mature moist forests had long fire intervals (50–160 years). Nearly all tree establishment cohorts were preceded by either stand-replacing (28 %) or non-stand-replacing fires (64 %). However, tree cohorts only provided evidence of 16 % of historical fire events that we reconstructed from cambial fire scars. This study demonstrates that frequent fire can be an important driver of forest development and in some contexts shapes the structure of coastal old-growth Douglas-fir forests, which are often characterized as developing from endogenous disturbances during long fire-free periods. The high level of pyrodiversity we observed was associated with variation in and interactions of micro-climate, topography, fuels, and Indigenous fire stewardship. We recommend rigorous dendroecological reconstructions across the coastal Douglas-fir region to refine our understanding of the geography of fire-mediated forest developmental dynamics in this important forest type, to inform forest management, conservation, and ecocultural restoration.</div></div>","PeriodicalId":12350,"journal":{"name":"Forest Ecology and Management","volume":"572 ","pages":"Article 122306"},"PeriodicalIF":3.7,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142323498","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"How dominant height responds to mixing species: Effect of traits and height difference between species","authors":"Matthieu Combaud ,&nbsp;Thomas Cordonnier ,&nbsp;Thomas Pérot ,&nbsp;Xavier Morin ,&nbsp;Patrick Vallet","doi":"10.1016/j.foreco.2024.122298","DOIUrl":"10.1016/j.foreco.2024.122298","url":null,"abstract":"<div><div>Adapting forests to climate change is a major challenge for forest ecology and forestry. Among the management options available, encouraging the use of mixtures is a promising way forward. However, this practice requires a thorough understanding of how species respond to mixing. In this article, we analyzed species dominant height responds to mixing and how species ontogeny and traits drive this response. We compared species observed dominant height in mixed even-aged stands with the expected dominant height of the same species in a monospecific stand under the same environmental conditions. We then related this dominant height variation due to mixing to between-species dominant height difference and to species traits linked to competition (shade tolerance, wood density, specific leaf area).</div><div>We focused our analyses on 76 pairs of forest tree species. We used data from the French National Forest Inventory to calculate species dominant height in 1368 mixed stands. We then used previously developed models to estimate the expected dominant height in virtual monospecific stands with the same environmental conditions.</div><div>We found that mixture had a significant impact on species dominant height for 15 out of 50 species-combination considered. Dominant height of a given species was higher in mixture than in pure stands when this species had a lower dominant height in pure stands, a lower shade tolerance, a lower specific leaf area or a higher wood density than its companion species.</div><div>Our results suggest that species dominant height response to mixing depends on how mixture influences the competition for light. Our results will help inform strategies aiming to diversify species in forests, and will be especially useful in anticipating a given species’ behavior in response to competition for light when it is mixed with other species.</div></div>","PeriodicalId":12350,"journal":{"name":"Forest Ecology and Management","volume":"572 ","pages":"Article 122298"},"PeriodicalIF":3.7,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142323578","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stand age controls canopy and soil rainfall partitioning in slash pine forests","authors":"Seyed Mohammad Moein Sadeghi ,&nbsp;Joshua M. Epstein ,&nbsp;Azade Deljouei ,&nbsp;Franklin J. Gorora ,&nbsp;Matthew J. Cohen","doi":"10.1016/j.foreco.2024.122307","DOIUrl":"10.1016/j.foreco.2024.122307","url":null,"abstract":"<div><div>Changing forest structure with stand development is predicted to influence rainfall partitioning, and thus impact forest management and conservation strategies. Extensive pine silviculture in Florida also makes changes in rainfall partitioning with stand attributes consequential for regional water planning. We used weekly measurements of rainfall partitioning and soil water infiltration in two contrasting <em>Pinus elliottii</em> (slash pine) forest ecosystems in north Florida (USA), to quantify stand age and structural development impacts on forest hydrological function. Over 52 weeks - 45 with storms - we observed that stemflow and litterflow were significantly higher, and litter and total interception significantly lower, in the young stand (∼ 10 years since planting) than the mature stand (∼ 21 years since planting) (p &lt;0.05). This was despite negligible differences in leaf area index and other crown structure parameters. We observed substantial differences in trunk storage capacity and trunk saturation point, with greater storage and thus reduced stemflow generation in the mature stand. We show that forest litter stores significant precipitation (7.3 % vs. 10.6 % of annual rainfall for young and mature pine stands, respectively) suggesting total interception predictions that neglect litter storage significantly underestimate actual rates, and overestimate root water availability. We further show that ignoring stemflow in small trees (i.e., young stands) underestimates total stemflow (3.4 % vs. 7.2 % of incident rainfall), leading to an overestimation of canopy and total interception in young stands. We used a reformulated Gash analytical model to obtain weekly estimates of canopy rainfall interception. Our most robust results were observed when we used in-situ partitioning parameters and dynamic canopy cover measurements. However, using literature-derived canopy ecohydrological parameters for southern pines also yielded acceptable predictions given dynamic canopy measurements, suggesting informative generality for application to new settings. Using static canopy measurements yielded consistently inferior results, suggesting that tracking canopy properties is more important for accurate interception predictions than local partitioning parameter estimation. Our results highlight the significance of forest maturity as a factor altering water storage capacity and rainfall partitioning in planted pine stands.</div></div>","PeriodicalId":12350,"journal":{"name":"Forest Ecology and Management","volume":"572 ","pages":"Article 122307"},"PeriodicalIF":3.7,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142323577","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessing assisted population migration (seed transfer) for eastern white pine at northern planting sites","authors":"Pengxin Lu ,&nbsp;Jean Beaulieu ,&nbsp;John Pedlar ,&nbsp;William C. Parker ,&nbsp;Daniel W. McKenney ,&nbsp;Lahcen Benomar","doi":"10.1016/j.foreco.2024.122309","DOIUrl":"10.1016/j.foreco.2024.122309","url":null,"abstract":"<div><div>Assisted population migration (APM) has been proposed as an adaptive strategy to enhance forest resilience and productivity under a warming climate. Previous studies have shown tangible benefits of APM on tree growth, including eastern white pine. However, climatic conditions strongly affecting tree growth may also influence the expression of provenance variation and, consequently, benefits from conducting APM. Estimated benefits of APM at warm field trial sites thus may not be attainable at colder northerly sites. In this study, we assessed the potential benefits of APM for eastern white pine at climatically mild and cold sites using data from six field provenance trials in Ontario and Quebec, Canada. Results indicated that annual tree height increment, inter-provenance variation, and achievable benefits from provenance selection were significantly affected by climatic conditions of trial sites. At climatically warm and mild sites where frost or winter low temperature did not cause tree injury, annual height increment was more than 50 % greater and achievable benefit was about twice as large as that at cold sites near the edge of species’ natural range limit. Provenance variation in survival was, however, negligible across trials. Based on patterns of spatial provenance variation, the southern and northern limits of provenances suitable for use as seed sources for planting sites in Ontario and Quebec were delineated using latitudinal coordinates or thermal variables. The potential benefits of APM at northerly sites in anticipation of future climate change are discussed.</div></div>","PeriodicalId":12350,"journal":{"name":"Forest Ecology and Management","volume":"572 ","pages":"Article 122309"},"PeriodicalIF":3.7,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142323496","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Die-hard seedlings. A global meta-analysis on the factors determining the effectiveness of drought hardening on growth and survival of forest plantations","authors":"Jaime Puértolas ,&nbsp;Pedro Villar-Salvador ,&nbsp;Enrique Andivia ,&nbsp;Ishita Ahuja ,&nbsp;Claudia Cocozza ,&nbsp;Branislav Cvjetković ,&nbsp;Jovana Devetaković ,&nbsp;Julio J. Diez ,&nbsp;Inger S. Fløistad ,&nbsp;Petros Ganatsas ,&nbsp;Barbara Mariotti ,&nbsp;Marianthi Tsakaldimi ,&nbsp;Alberto Vilagrosa ,&nbsp;Johanna Witzell ,&nbsp;Vladan Ivetić","doi":"10.1016/j.foreco.2024.122300","DOIUrl":"10.1016/j.foreco.2024.122300","url":null,"abstract":"<div><div>Drought hardening is a nursery technique aimed to enhance early forest plantation establishment under dry conditions, which is a main limiting factors for plantation success. However, the quantitative effectiveness of drought hardening remains unclear. We conducted a meta-analysis to evaluate the influence of different factors in the effectiveness of drought hardening on seedling post-planting survival and growth. Overall, drought hardening did not significantly affect survival or growth, as several factors induced great heterogeneity, but analyses of those factors explained its effectiveness, especially on survival. A longer time between hardening and transplanting strongly reduced survival. Indoor-grown seedlings did not benefit more from hardening than outdoor-grown seedlings. Evaluations of drought hardening effectiveness in pots showed positive effects on survival but negative effects on growth, while no effects were found in large bed experiments. In field experiments, hardening significantly increased survival and growth with site aridity. Survival benefits were independent of species drought tolerance, measured by osmotic potential at the turgor loss point (π_tlp), in moderate to high aridity sites. However, in low aridity sites, hardening increased survival in drought-tolerant species but decreased it in drought-intolerant species. Field results showed that hardening benefited shrubs more than trees in angiosperms. In conclusion, drought hardening at the end of nursery cultivation tend to increase post-planting seedling performance particularly in scenarios limiting post-planting root growth such as in arid climates and pot experiments. Our findings highlight the importance of future research on modelling the interaction between these technical features and species water use strategies..</div></div>","PeriodicalId":12350,"journal":{"name":"Forest Ecology and Management","volume":"572 ","pages":"Article 122300"},"PeriodicalIF":3.7,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142323497","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterizing the competitive stress of individual trees using point clouds","authors":"Ghasem Ronoud ,&nbsp;Maryam Poorazimy ,&nbsp;Tuomas Yrttimaa ,&nbsp;Antero Kukko ,&nbsp;Juha Hyyppä ,&nbsp;Ninni Saarinen ,&nbsp;Ville Kankare ,&nbsp;Mikko Vastaranta","doi":"10.1016/j.foreco.2024.122305","DOIUrl":"10.1016/j.foreco.2024.122305","url":null,"abstract":"&lt;div&gt;&lt;div&gt;The competitive stress of individual trees can be quantified by considering their positions and dimensions such as diameter at breast height (dbh) and height with respect to their neighbor trees. However, measurements of these attributes in the field limit the number of trees and stands that can be assessed with given resources. In recent years, terrestrial laser scanning (TLS) and airborne laser scanning (ALS) data have become prominent in characterizing three-dimensional forest structures. These data could also provide efficient and reliable tools to assess the competitive stress of trees within a stand. Therefore, we aimed to investigate the capability of TLS and low-altitude ALS in characterizing the competitive stress affecting individual trees in boreal forests. We compared: a) an object-based approach that quantified competition through the identification and characterization of competing neighbor trees from the TLS and ALS point clouds, and b) a point cloud-based approach where the presence of point cloud structures representing competitive vegetation around a target tree was considered. Accordingly, three object-based competition indices (CIs) utilizing dbh (CI&lt;sub&gt;dbh&lt;/sub&gt;), height (CI&lt;sub&gt;H&lt;/sub&gt;), and maximum crown diameter (CI&lt;sub&gt;MCD&lt;/sub&gt;) as weights were calculated using the Hegyi equation. For the point cloud-based approach, the canopy density index (CDI), and the competitive pressure index (CPI) were derived using an upside-down search cone set at 60 % relative tree height, while the CI&lt;sub&gt;Cylinder&lt;/sub&gt; was calculated by counting the number of voxels occupied by the competitive vegetation inside a fixed-radius cylinder. These laser scanning-based CIs were assessed against &lt;em&gt;in situ&lt;/em&gt;-based CIs where dbh and height were used as weights in the Hegyi equation. The results showed that the object-based CIs were more correlated (&lt;em&gt;r&lt;/em&gt; = 0.33–0.48, &lt;em&gt;p-&lt;/em&gt;value &lt; 0.001) with the &lt;em&gt;in situ&lt;/em&gt;-based CIs in comparison with the point cloud-based CIs (&lt;em&gt;r&lt;/em&gt; = −0.22–0.37). The object-based CIs showed a high correlation (&lt;em&gt;r&lt;/em&gt; = 0.65–0.71, &lt;em&gt;p-&lt;/em&gt;value &lt; 0.001) when compared between TLS and ALS, while a greater variation was observed for the point cloud-based CIs (&lt;em&gt;r&lt;/em&gt; = 0.29–0.53, &lt;em&gt;p-&lt;/em&gt;value &lt; 0.001). Tree detection rate and the number of neighboring trees in the field affected how well the CIs derived from the TLS and ALS data were in line with the &lt;em&gt;in situ&lt;/em&gt;-based CIs, especially when the competitive stress was assessed using the object-based CIs. In conclusion, the object-based CIs derived using TLS and ALS provided consistent characterization of competition in managed boreal forests compared to the &lt;em&gt;in situ&lt;/em&gt;-based CIs. While TLS is ideal for small-scale assessments, low-altitude ALS offers a rather similar capacity for assessing competition but with broader coverage. In complex forest structures, reliable tree detection is essential to avoid underestimating th","PeriodicalId":12350,"journal":{"name":"Forest Ecology and Management","volume":"572 ","pages":"Article 122305"},"PeriodicalIF":3.7,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142320139","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}