Pub Date : 2024-11-24DOI: 10.1016/j.foreco.2024.122400
Matteo Cerioni, Matija Klopčič, Dušan Roženbergar, Thomas A. Nagel
Compound disturbances are anticipated to increase under global change, potentially resulting in unpredictable forest recovery dynamics, especially in managed forests where salvage logging is often routine, yet studies quantifying forest resilience to compound disturbances are still scarce. We investigated resilience to an ice storm event, followed by a spruce bark beetle outbreak and subsequent salvage logging in a temperate sub-montane forest landscape in Slovenia. The study landscape was characterized by a gradient in pre-disturbance proportion of spruce, an important species for the forest economy, ranging from mixed fir-beech-spruce forest to spruce monocultures. Given that the bark beetle only affected spruce, this gradient in spruce proportion provided an opportunity to investigate forest resilience across a severity gradient ranging from undamaged areas to complete canopy removal over patches of several hectares. We assessed multiple dimensions of resilience across this disturbance severity gradient, namely i) post-disturbance forest structural and species diversity, ii) radial growth of surviving trees, and iii) post-disturbance regeneration, including measurements made in deer exclosures. The results highlight the low resilience of spruce-dominated stands in terms of low structural and species diversity of the recovering forests, once spruce is removed due to disturbance. However, measures of post-disturbance structural diversity were higher in stands were spruce made up < 50 % of the tree composition. This result may help forest managers to plan how much spruce to maintain in mixture with species less vulnerable to climate change. We also showed that surviving canopy trees with damaged crowns can sustain high radial growth resilience, which calls into question the efficacy of immediate post-disturbance salvaging of damaged trees. Finally, we quantified the detrimental impact of ungulate browsing on the recruitment of post-disturbance regeneration, particularly for highly palatable species, which showed significantly lower aggregate height, a metric combining density and tree height, outside of deer exclosures. We stress the importance of actively controlling ungulate populations for successful post-disturbance recruitment of silviculturally important palatable species, such as silver fir and sycamore maple.
{"title":"Multiple dimensions of forest resilience to compound disturbances in a mixed sub-montane forest landscape","authors":"Matteo Cerioni, Matija Klopčič, Dušan Roženbergar, Thomas A. Nagel","doi":"10.1016/j.foreco.2024.122400","DOIUrl":"10.1016/j.foreco.2024.122400","url":null,"abstract":"<div><div>Compound disturbances are anticipated to increase under global change, potentially resulting in unpredictable forest recovery dynamics, especially in managed forests where salvage logging is often routine, yet studies quantifying forest resilience to compound disturbances are still scarce. We investigated resilience to an ice storm event, followed by a spruce bark beetle outbreak and subsequent salvage logging in a temperate sub-montane forest landscape in Slovenia. The study landscape was characterized by a gradient in pre-disturbance proportion of spruce, an important species for the forest economy, ranging from mixed fir-beech-spruce forest to spruce monocultures. Given that the bark beetle only affected spruce, this gradient in spruce proportion provided an opportunity to investigate forest resilience across a severity gradient ranging from undamaged areas to complete canopy removal over patches of several hectares. We assessed multiple dimensions of resilience across this disturbance severity gradient, namely i) post-disturbance forest structural and species diversity, ii) radial growth of surviving trees, and iii) post-disturbance regeneration, including measurements made in deer exclosures. The results highlight the low resilience of spruce-dominated stands in terms of low structural and species diversity of the recovering forests, once spruce is removed due to disturbance. However, measures of post-disturbance structural diversity were higher in stands were spruce made up < 50 % of the tree composition. This result may help forest managers to plan how much spruce to maintain in mixture with species less vulnerable to climate change. We also showed that surviving canopy trees with damaged crowns can sustain high radial growth resilience, which calls into question the efficacy of immediate post-disturbance salvaging of damaged trees. Finally, we quantified the detrimental impact of ungulate browsing on the recruitment of post-disturbance regeneration, particularly for highly palatable species, which showed significantly lower aggregate height, a metric combining density and tree height, outside of deer exclosures. We stress the importance of actively controlling ungulate populations for successful post-disturbance recruitment of silviculturally important palatable species, such as silver fir and sycamore maple.</div></div>","PeriodicalId":12350,"journal":{"name":"Forest Ecology and Management","volume":"577 ","pages":"Article 122400"},"PeriodicalIF":3.7,"publicationDate":"2024-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142721426","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}
Pub Date : 2024-11-23DOI: 10.1016/j.foreco.2024.122407
Adrian Zwolicki
Beavers, as ecosystem engineers, significantly affect riparian ecosystems, mostly through foraging and dams construction. This study examines how beaver-related tree cutting altered canopy openness and affected microhabitats and forest floor vegetation in the Northern Poland’s Tuchola Forest. Woody plant characteristics, forest floor vegetation abundance, and canopy openness were assessed at three sites varying in forest naturalness, with canopy openness being measured using hemispherical photography. Results show that selective tree removal by beavers from all diameter classes significantly increased canopy openness. This alteration leads to transformative changes in forest habitat properties, notably increasing light availability, and to nutrient status changes as evidenced by shifts in Ellenberg indicator values. Consequently, these changes result in increased forest floor total vegetation cover, diversity and composition. The cascading effects of beaver tree-cutting on canopy alterations have been comprehensively modelled using structural equation models. The study also reveals distinct spatial patterns in canopy alterations, with the most pronounced effects near riverbanks. The intensified impact of beaver activities, could be linked to the naturalness of the forest, and might be especially pronounced in more altered environments, particularly where pioneer aspen trees dominate the tree stand composition. These findings underscore the role of beavers in shaping forest dynamics, particularly in managed or disturbed forests. By creating canopy gaps, beavers initiate processes that enhance habitat heterogeneity and biodiversity, suggesting that their presence may be crucial for the restoration of natural processes in disturbed ecosystems.
{"title":"Can beavers canopy alterations affect managed forests more than natural forests?","authors":"Adrian Zwolicki","doi":"10.1016/j.foreco.2024.122407","DOIUrl":"10.1016/j.foreco.2024.122407","url":null,"abstract":"<div><div>Beavers, as ecosystem engineers, significantly affect riparian ecosystems, mostly through foraging and dams construction. This study examines how beaver-related tree cutting altered canopy openness and affected microhabitats and forest floor vegetation in the Northern Poland’s Tuchola Forest. Woody plant characteristics, forest floor vegetation abundance, and canopy openness were assessed at three sites varying in forest naturalness, with canopy openness being measured using hemispherical photography. Results show that selective tree removal by beavers from all diameter classes significantly increased canopy openness. This alteration leads to transformative changes in forest habitat properties, notably increasing light availability, and to nutrient status changes as evidenced by shifts in Ellenberg indicator values. Consequently, these changes result in increased forest floor total vegetation cover, diversity and composition. The cascading effects of beaver tree-cutting on canopy alterations have been comprehensively modelled using structural equation models. The study also reveals distinct spatial patterns in canopy alterations, with the most pronounced effects near riverbanks. The intensified impact of beaver activities, could be linked to the naturalness of the forest, and might be especially pronounced in more altered environments, particularly where pioneer aspen trees dominate the tree stand composition. These findings underscore the role of beavers in shaping forest dynamics, particularly in managed or disturbed forests. By creating canopy gaps, beavers initiate processes that enhance habitat heterogeneity and biodiversity, suggesting that their presence may be crucial for the restoration of natural processes in disturbed ecosystems.</div></div>","PeriodicalId":12350,"journal":{"name":"Forest Ecology and Management","volume":"577 ","pages":"Article 122407"},"PeriodicalIF":3.7,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142721544","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}
Riparian forests are among the most vulnerable ecosystems to biological invasions. Effective management strategies require a nuanced understanding of both species invasiveness and environmental conditions, but analysing these interactions is complex. We designed an Agent-Based Model (ABM) to simulate the spatio-temporal spread of Gleditsia triacanthos in the riparian forest of the Esteros de Farrapos e Islas del Río Uruguay National Park; Uruguay. This is a parsimonious and generalisable model that incorporates distinctive features of woody invasions in riparian systems—such as environmental heterogeneity and flooding regimes—as well as common characteristics of woody invaders. Management simulations suggest that if control measures are maintained over time, the abundance of the invader will remain constant at low levels; thus, the invasion can be controlled, even if not completely eradicated. The results also indicate that without control, the invasion process would spread even into unsuitable areas. The SWIRS model facilitates the evaluation of targeted management strategies, ultimately providing a framework to enhance biodiversity conservation efforts in riparian ecosystems.
河岸森林是最容易受到生物入侵影响的生态系统之一。有效的管理策略需要对物种入侵和环境条件有细致入微的了解，但分析这些相互作用非常复杂。我们设计了一个基于代理的模型（ABM）来模拟三尖杉（Gleditsia triacanthos）在乌拉圭 Esteros de Farrapos e Islas del Río Uruguay 国家公园河岸林中的时空传播。这是一个简明且可推广的模型，包含了河岸系统中木质入侵的显著特征（如环境异质性和洪水制度）以及木质入侵者的共同特征。管理模拟结果表明，如果长期坚持采取控制措施，入侵者的数量将保持在较低水平；因此，即使不能完全根除入侵，也可以对其进行控制。结果还表明，如果不采取控制措施，入侵过程甚至会蔓延到不适宜的地区。SWIRS 模型有助于评估有针对性的管理策略，最终为加强河岸生态系统的生物多样性保护工作提供了一个框架。
{"title":"Explaining woody invasions in riparian systems with agent-based simulations: Implications for conservation management","authors":"Beatriz Sosa , Moira Zellner , Carlos Chiale , Marcel Achkar","doi":"10.1016/j.foreco.2024.122363","DOIUrl":"10.1016/j.foreco.2024.122363","url":null,"abstract":"<div><div>Riparian forests are among the most vulnerable ecosystems to biological invasions. Effective management strategies require a nuanced understanding of both species invasiveness and environmental conditions, but analysing these interactions is complex. We designed an Agent-Based Model (ABM) to simulate the spatio-temporal spread of <em>Gleditsia triacanthos</em> in the riparian forest of the Esteros de Farrapos e Islas del Río Uruguay National Park; Uruguay. This is a parsimonious and generalisable model that incorporates distinctive features of woody invasions in riparian systems—such as environmental heterogeneity and flooding regimes—as well as common characteristics of woody invaders. Management simulations suggest that if control measures are maintained over time, the abundance of the invader will remain constant at low levels; thus, the invasion can be controlled, even if not completely eradicated. The results also indicate that without control, the invasion process would spread even into unsuitable areas. The SWIRS model facilitates the evaluation of targeted management strategies, ultimately providing a framework to enhance biodiversity conservation efforts in riparian ecosystems.</div></div>","PeriodicalId":12350,"journal":{"name":"Forest Ecology and Management","volume":"576 ","pages":"Article 122363"},"PeriodicalIF":3.7,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142702453","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}
Pub Date : 2024-11-21DOI: 10.1016/j.foreco.2024.122385
Ángel Ponce , Maitane Erdozain , Josu G. Alday , José Antonio Bonet , Juan Martínez de Aragón , Sergio de-Miguel
Pine forests represent globally distributed conifers growing in a wide range of habitats within the Mediterranean basin. One example are the high-altitude mountain pine (Pinus uncinata) forests in the Pyrenees, which stand out for their high fungal sporocarps richness. Nevertheless, studies on the effects of forest management on sporocarps diversity in mountain pine forests have been lacking, despite their importance for optimizing multiple-use forestry practices. To address this gap, we analysed the impact of different thinning intensities on fungal sporocarp diversity and composition in P. uncinata stands in the Pyrenees. The experimental design involved a BACI approach used to compare annual sporocarp diversity and composition five years before and three years after the thinning intervention in 18 permanent plots (9 thinned and 9 control). The results indicated an absence of a thinning effect in the lighter thinning intensities (< 25 % of basal area removal) for the sporocarp richness, while negative effects emerged steadily when increasing the thinning intensity until a clear negative effect reported when removing more than 70 % of the basal area. Sporocarp evenness and Shannon index revealed a negative effect due to forest thinning, with a dominance of some species that can cope with the new stand conditions. The ECM sporocarp composition was mainly affected by interannual variability, while the saprotrophic sporocarp composition was mainly driven by site conditions. However, in both guilds, we detected a reduction of the sporocarps fructification in the higher thinning intensities. Our results indicate that lighter thinning intensities do not compromise fungal diversity conservation. Finally, forest management practices that balance timber production and fungal diversity could create opportunities to enhance the ecological, social and economic value of these forest stands, which have historically been managed exclusively for timber purposes.
{"title":"Effect of forest thinning on the diversity and composition of macrofungal sporocarps in Pinus uncinata stands","authors":"Ángel Ponce , Maitane Erdozain , Josu G. Alday , José Antonio Bonet , Juan Martínez de Aragón , Sergio de-Miguel","doi":"10.1016/j.foreco.2024.122385","DOIUrl":"10.1016/j.foreco.2024.122385","url":null,"abstract":"<div><div>Pine forests represent globally distributed conifers growing in a wide range of habitats within the Mediterranean basin. One example are the high-altitude mountain pine (<em>Pinus uncinata</em>) forests in the Pyrenees, which stand out for their high fungal sporocarps richness. Nevertheless, studies on the effects of forest management on sporocarps diversity in mountain pine forests have been lacking, despite their importance for optimizing multiple-use forestry practices. To address this gap, we analysed the impact of different thinning intensities on fungal sporocarp diversity and composition in <em>P. uncinata</em> stands in the Pyrenees. The experimental design involved a BACI approach used to compare annual sporocarp diversity and composition five years before and three years after the thinning intervention in 18 permanent plots (9 thinned and 9 control). The results indicated an absence of a thinning effect in the lighter thinning intensities (< 25 % of basal area removal) for the sporocarp richness, while negative effects emerged steadily when increasing the thinning intensity until a clear negative effect reported when removing more than 70 % of the basal area. Sporocarp evenness and Shannon index revealed a negative effect due to forest thinning, with a dominance of some species that can cope with the new stand conditions. The ECM sporocarp composition was mainly affected by interannual variability, while the saprotrophic sporocarp composition was mainly driven by site conditions. However, in both guilds, we detected a reduction of the sporocarps fructification in the higher thinning intensities. Our results indicate that lighter thinning intensities do not compromise fungal diversity conservation. Finally, forest management practices that balance timber production and fungal diversity could create opportunities to enhance the ecological, social and economic value of these forest stands, which have historically been managed exclusively for timber purposes.</div></div>","PeriodicalId":12350,"journal":{"name":"Forest Ecology and Management","volume":"576 ","pages":"Article 122385"},"PeriodicalIF":3.7,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142702449","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}
Pub Date : 2024-11-21DOI: 10.1016/j.foreco.2024.122405
Jan Kadavý, Michal Kneifl, Barbora Uherková
Traditional clear-cutting of even-aged plantations has become less desirable, with forestry shifting towards more diverse, multi-purpose integrated forest management. This study compared easily selected forest structures in managed forests and forest reserves to guide integrated forest management. The study area includes six managed forest areas and six forest reserves, with management types compared over approximately 50 years. The evaluated areas are part of the university forests of Mendel University in Brno, covering approximately 30 km² of natural deciduous temperate forests, predominantly composed of sessile oak and European beech. A total of 599 inventory plots were surveyed, assessing the presence or absence of selected forest structures in six categories. Twelve logistic generalized mixed models were developed to estimate the probability of occurrence of the observed forest structures based on their management status. Significant differences were found in the categories of dead standing and lying wood, microhabitat trees, and non-native tree species, with all variables showing a higher probability in forest reserves compared to managed forests. The results support the shift towards integrative management by incorporating elements of retention forestry. However, certain variables, such as natural regeneration and species diversity, showed little variation between management types, suggesting that some forest attributes are resilient to management practices.
{"title":"Comparison of selected structural elements of managed and unmanaged forest to guide integrated forest management","authors":"Jan Kadavý, Michal Kneifl, Barbora Uherková","doi":"10.1016/j.foreco.2024.122405","DOIUrl":"10.1016/j.foreco.2024.122405","url":null,"abstract":"<div><div>Traditional clear-cutting of even-aged plantations has become less desirable, with forestry shifting towards more diverse, multi-purpose integrated forest management. This study compared easily selected forest structures in managed forests and forest reserves to guide integrated forest management. The study area includes six managed forest areas and six forest reserves, with management types compared over approximately 50 years. The evaluated areas are part of the university forests of Mendel University in Brno, covering approximately 30 km² of natural deciduous temperate forests, predominantly composed of sessile oak and European beech. A total of 599 inventory plots were surveyed, assessing the presence or absence of selected forest structures in six categories. Twelve logistic generalized mixed models were developed to estimate the probability of occurrence of the observed forest structures based on their management status. Significant differences were found in the categories of dead standing and lying wood, microhabitat trees, and non-native tree species, with all variables showing a higher probability in forest reserves compared to managed forests. The results support the shift towards integrative management by incorporating elements of retention forestry. However, certain variables, such as natural regeneration and species diversity, showed little variation between management types, suggesting that some forest attributes are resilient to management practices.</div></div>","PeriodicalId":12350,"journal":{"name":"Forest Ecology and Management","volume":"576 ","pages":"Article 122405"},"PeriodicalIF":3.7,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142702451","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}
Pub Date : 2024-11-21DOI: 10.1016/j.foreco.2024.122404
Elena Razenkova , Shawn Fraver , Brian J. Palik , Evan Peepo , Jed Meunier
Heterogeneous spatial patterns are an important characteristic of forests and central to forest functioning and resilience. Old forests typically have complex structures and provide useful starting points from which to understand processes assembling forest communities and in turn managing for resilience. In the U.S. Lake States, extant old growth forests are rare, especially dry, frequent fire forest types. In this study we analyzed components (e.g., canopy characteristics) and spatial patterning (tree density, arrangement) of old growth red pine stands for developing metrics of silviculture prescriptions. Our data indicate that reference red pine stands are currently > 6 times denser than historical (ca. 1860) conditions, and current tree spacing formed a single large clump after just 4–6-meter inter-tree distances. Historically, these stands had complex spatial arrangements and contained a diversity of size, age, height, and canopy structures. By characterizing spatial arrangements of stands in terms of individuals, clumps, and openings, we offer both a reference point, and basis of management for dry, red pine dominated forest types in Wisconsin and Minnesota to maintain or restore more spatially complex forests.
{"title":"Analyzing spatial patterns of old-growth red pine dominated forests in Wisconsin and Minnesota as a tool to increase forest resilience","authors":"Elena Razenkova , Shawn Fraver , Brian J. Palik , Evan Peepo , Jed Meunier","doi":"10.1016/j.foreco.2024.122404","DOIUrl":"10.1016/j.foreco.2024.122404","url":null,"abstract":"<div><div>Heterogeneous spatial patterns are an important characteristic of forests and central to forest functioning and resilience. Old forests typically have complex structures and provide useful starting points from which to understand processes assembling forest communities and in turn managing for resilience. In the U.S. Lake States, extant old growth forests are rare, especially dry, frequent fire forest types. In this study we analyzed components (e.g., canopy characteristics) and spatial patterning (tree density, arrangement) of old growth red pine stands for developing metrics of silviculture prescriptions. Our data indicate that reference red pine stands are currently > 6 times denser than historical (ca. 1860) conditions, and current tree spacing formed a single large clump after just 4–6-meter inter-tree distances. Historically, these stands had complex spatial arrangements and contained a diversity of size, age, height, and canopy structures. By characterizing spatial arrangements of stands in terms of individuals, clumps, and openings, we offer both a reference point, and basis of management for dry, red pine dominated forest types in Wisconsin and Minnesota to maintain or restore more spatially complex forests.</div></div>","PeriodicalId":12350,"journal":{"name":"Forest Ecology and Management","volume":"576 ","pages":"Article 122404"},"PeriodicalIF":3.7,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142702452","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}
Pub Date : 2024-11-21DOI: 10.1016/j.foreco.2024.122406
Hao Wu , Linyu Lyu , Zhiqiang Xiao , Teng Yang , Mingxi Jiang , Xinzeng Wei
The regeneration of plants endemic to remote mountain areas is thought to be relatively unimpacted by human disturbances but rather dominated by abiotic factors, such as geography, climate, and soil. However, because human disturbances are accelerating the extinction of montane plants and the loss of montane forest, this balance may be shifting. Yet, the relative effects of abiotic factors and human disturbances to montane plant regeneration are still largely unclear. Here, we investigated the geographic pattern of regeneration (ratio of seedling and ratio of sprout) and assessed the impacts of abiotic and anthropogenic factors for an endangered montane tree species (Davidia involucrata) across its distribution range in China. We found that the ratio of seedling increased from south to north, whereas the ratio of sprout exhibited an opposite pattern, indicating that under climate warming this species may adopt sprout regeneration as a potential strategy to buffer population contraction at the southern edge. Moreover, while climatic factors were the main drivers of regeneration, anthropogenic factors were also important. Of note, the proportion of pasture land area had a significant positive effect on sprouting, with more sprout regeneration at grazed sites and a higher ratio of sprout at sites with a greater intensity of human disturbance. Our findings suggested that, in addition to climate change, human disturbance is also an important driving factor of the regeneration of plants native to remote mountain areas, and we emphasized that researchers and policymakers should take it into account when protecting endangered plants and managing forest biodiversity.
{"title":"Regeneration of an endangered plant species endemic to the remote mountain areas: Anthropogenic disturbance matters","authors":"Hao Wu , Linyu Lyu , Zhiqiang Xiao , Teng Yang , Mingxi Jiang , Xinzeng Wei","doi":"10.1016/j.foreco.2024.122406","DOIUrl":"10.1016/j.foreco.2024.122406","url":null,"abstract":"<div><div>The regeneration of plants endemic to remote mountain areas is thought to be relatively unimpacted by human disturbances but rather dominated by abiotic factors, such as geography, climate, and soil. However, because human disturbances are accelerating the extinction of montane plants and the loss of montane forest, this balance may be shifting. Yet, the relative effects of abiotic factors and human disturbances to montane plant regeneration are still largely unclear. Here, we investigated the geographic pattern of regeneration (ratio of seedling and ratio of sprout) and assessed the impacts of abiotic and anthropogenic factors for an endangered montane tree species (<em>Davidia involucrata</em>) across its distribution range in China. We found that the ratio of seedling increased from south to north, whereas the ratio of sprout exhibited an opposite pattern, indicating that under climate warming this species may adopt sprout regeneration as a potential strategy to buffer population contraction at the southern edge. Moreover, while climatic factors were the main drivers of regeneration, anthropogenic factors were also important. Of note, the proportion of pasture land area had a significant positive effect on sprouting, with more sprout regeneration at grazed sites and a higher ratio of sprout at sites with a greater intensity of human disturbance. Our findings suggested that, in addition to climate change, human disturbance is also an important driving factor of the regeneration of plants native to remote mountain areas, and we emphasized that researchers and policymakers should take it into account when protecting endangered plants and managing forest biodiversity.</div></div>","PeriodicalId":12350,"journal":{"name":"Forest Ecology and Management","volume":"576 ","pages":"Article 122406"},"PeriodicalIF":3.7,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142702454","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}
Pub Date : 2024-11-21DOI: 10.1016/j.foreco.2024.122408
Sarita Bassil, Robert E. Froese, Bradley D. Pinno
In early 2000s, long-distance wind dispersal of mountain pine beetle (MPB; Dendroctonus ponderosae Hopkins) resulted in massive outbreaks in the northern Rocky Mountains, Alberta, Canada, outside of the beetle’s natural range. We analyzed data from permanent plots measured for up to 15 years after MPB outbreaks in fire-origin, mature lodgepole pine (Pinus contorta var. latifolia Engelm.)-dominated stands scattered over an area of ∼ 75,000 km2. We evaluated stand level stocking, regeneration, and ingrowth of three species groups (pine, shade-tolerant conifers, and broadleaves) in stands where > 50 % of pine basal area was killed. Using multiple linear regression analysis, we examined the relationship between stand and climatic covariates and basal area growth, density of regeneration, and ingrowth into the sapling size class at 9–15 years post-outbreak. Results showed that total live basal area for all species combined in trees with height ≥ 1.3 m occupies on average < 50 % of the pre-MPB levels and is unchanged between both post-MPB measurements at 19.5 m2 ha−1. Ongoing pine mortality led to negative net growth, which exceeded the positive net growth in other conifers and resulted in zero net change for the whole stand. Post-MPB ingrowth and regeneration rates were close to zero for pine but increased slightly in other conifers and broadleaf species. Regression analysis revealed a negative relation between post-MPB growth and quadratic mean diameter of the reconstructed pre-MPB total basal area, while initial basal area and composition post-MPB varied among species. Our findings support the hypothesis that, post-MPB, mature pine dominated stands stagnate due to ongoing pine mortality, the maturity of remnant overstory, and a lack of adequate understory and regeneration that can accumulate sufficient growth at short-to mid-term post-outbreak. Our conclusions contrast other research, suggesting that outbreaks leave degraded residual stands with declining pine overstory and that transition to vigorous productive mixed stands is impossible in the absence of stand-replacing disturbance or silvicultural investment.
{"title":"Little recovery of the residual stand after mountain pine beetle disturbance in old stands in the northern Rocky Mountains, Alberta, Canada.","authors":"Sarita Bassil, Robert E. Froese, Bradley D. Pinno","doi":"10.1016/j.foreco.2024.122408","DOIUrl":"10.1016/j.foreco.2024.122408","url":null,"abstract":"<div><div>In early 2000s, long-distance wind dispersal of mountain pine beetle (MPB; <em>Dendroctonus ponderosae</em> Hopkins) resulted in massive outbreaks in the northern Rocky Mountains, Alberta, Canada, outside of the beetle’s natural range. We analyzed data from permanent plots measured for up to 15 years after MPB outbreaks in fire-origin, mature lodgepole pine (<em>Pinus contorta</em> var. <em>latifolia</em> Engelm.)-dominated stands scattered over an area of ∼ 75,000 km<sup>2</sup>. We evaluated stand level stocking, regeneration, and ingrowth of three species groups (pine, shade-tolerant conifers, and broadleaves) in stands where > 50 % of pine basal area was killed. Using multiple linear regression analysis, we examined the relationship between stand and climatic covariates and basal area growth, density of regeneration, and ingrowth into the sapling size class at 9–15 years post-outbreak. Results showed that total live basal area for all species combined in trees with height ≥ 1.3 m occupies on average < 50 % of the pre-MPB levels and is unchanged between both post-MPB measurements at 19.5 m<sup>2</sup> ha<sup>−1</sup>. Ongoing pine mortality led to negative net growth, which exceeded the positive net growth in other conifers and resulted in zero net change for the whole stand. Post-MPB ingrowth and regeneration rates were close to zero for pine but increased slightly in other conifers and broadleaf species. Regression analysis revealed a negative relation between post-MPB growth and quadratic mean diameter of the reconstructed pre-MPB total basal area, while initial basal area and composition post-MPB varied among species. Our findings support the hypothesis that, post-MPB, mature pine dominated stands stagnate due to ongoing pine mortality, the maturity of remnant overstory, and a lack of adequate understory and regeneration that can accumulate sufficient growth at short-to mid-term post-outbreak. Our conclusions contrast other research, suggesting that outbreaks leave degraded residual stands with declining pine overstory and that transition to vigorous productive mixed stands is impossible in the absence of stand-replacing disturbance or silvicultural investment.</div></div>","PeriodicalId":12350,"journal":{"name":"Forest Ecology and Management","volume":"576 ","pages":"Article 122408"},"PeriodicalIF":3.7,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142702450","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}
Pub Date : 2024-11-20DOI: 10.1016/j.foreco.2024.122374
Daesung Lee , Jouni Siipilehto , Jari Hynynen
Identifying self-thinning phase is one of the key issues to deal with stand density management and simulate the growth and yield in a forest stand. This study was conducted to figure out the carrying capacity of silver birch plantations and provide the self-thinning zone for practicability. The analyzed data were the stand-wise observations from the experimental plots of silver birch plantations in southern and central Finland, which were established and measured between 1977 and 2020. Models for the diameter-based maximum size-density relationship (MSDR) were fitted only to the censored data after classifying the stand observations undergoing self-thinning phase. The applied diameter-based MSDR in this study were Reineke’s self-thinning rule (STR), competition-density (C-D) rule, and Nilson’s stand sparsity index (SSI). Model fitting was executed using linear quantile mixed-effect model for Reineke’s STR and Nilson’s SSI and nonlinear mixed-effect model for the C-D rule. For practical purpose, a lower boundary of the self-thinning zone based on the developed MSDR was analyzed using the concept of relative density (RD) according to the ratio of stem number (N) to maximum stem number (Nmax) at quadratic mean diameter (DQ). Linear quantile mixed models were fitted well with the 0.99 level for Reineke’s STR and with the 0.01 level for Nilson’s SSI to find the MSDR between DQ and N. Among the fitting methods for the C-D rule, the three-parameter method performed better than the four-parameter method or the method with Reineke’s slope of −1.605. The fitted slope of Reineke’s STR in this study was −1.5848, which was close to the original slope from Reineke’s. Our results from the developed models and the observations undergoing self-thinning phase implied that the slope of MSDR is not always invariant. Moreover, a different slope for MSDR was suggested by initial planting density and the stand development stage; a self-thinning phase occurred earlier with lower initial planting density, which meant a steeper slope. When the lower boundary of the self-thinning zone was analyzed applying RD to the MSDR models, the results suggested that RD 0.7 for Reineke’s STR at DQ ≤ 18.65 cm and RD 0.8 for Nilson’s SSI at DQ ≥ 18.65 cm provided adequate level for self-thinning phase. It is considered in this study that the diameter-based MSDR measures were analyzed and examined adequately, and the practical self-thinning zone was provided using RD for silver birch plantations.
{"title":"Comparison and analysis of self-thinning models based on diameter-based maximum size-density relationships","authors":"Daesung Lee , Jouni Siipilehto , Jari Hynynen","doi":"10.1016/j.foreco.2024.122374","DOIUrl":"10.1016/j.foreco.2024.122374","url":null,"abstract":"<div><div>Identifying self-thinning phase is one of the key issues to deal with stand density management and simulate the growth and yield in a forest stand. This study was conducted to figure out the carrying capacity of silver birch plantations and provide the self-thinning zone for practicability. The analyzed data were the stand-wise observations from the experimental plots of silver birch plantations in southern and central Finland, which were established and measured between 1977 and 2020. Models for the diameter-based maximum size-density relationship (MSDR) were fitted only to the censored data after classifying the stand observations undergoing self-thinning phase. The applied diameter-based MSDR in this study were Reineke’s self-thinning rule (STR), competition-density (C-D) rule, and Nilson’s stand sparsity index (SSI). Model fitting was executed using linear quantile mixed-effect model for Reineke’s STR and Nilson’s SSI and nonlinear mixed-effect model for the C-D rule. For practical purpose, a lower boundary of the self-thinning zone based on the developed MSDR was analyzed using the concept of relative density (<em>RD</em>) according to the ratio of stem number (<em>N</em>) to maximum stem number (<em>N</em><sub><em>max</em></sub>) at quadratic mean diameter (<em>DQ</em>). Linear quantile mixed models were fitted well with the 0.99 level for Reineke’s STR and with the 0.01 level for Nilson’s SSI to find the MSDR between <em>DQ</em> and <em>N</em>. Among the fitting methods for the C-D rule, the three-parameter method performed better than the four-parameter method or the method with Reineke’s slope of −1.605. The fitted slope of Reineke’s STR in this study was −1.5848, which was close to the original slope from Reineke’s. Our results from the developed models and the observations undergoing self-thinning phase implied that the slope of MSDR is not always invariant. Moreover, a different slope for MSDR was suggested by initial planting density and the stand development stage; a self-thinning phase occurred earlier with lower initial planting density, which meant a steeper slope. When the lower boundary of the self-thinning zone was analyzed applying <em>RD</em> to the MSDR models, the results suggested that <em>RD</em> 0.7 for Reineke’s STR at <em>DQ</em> ≤ 18.65 cm and <em>RD</em> 0.8 for Nilson’s SSI at <em>DQ</em> ≥ 18.65 cm provided adequate level for self-thinning phase. It is considered in this study that the diameter-based MSDR measures were analyzed and examined adequately, and the practical self-thinning zone was provided using <em>RD</em> for silver birch plantations.</div></div>","PeriodicalId":12350,"journal":{"name":"Forest Ecology and Management","volume":"575 ","pages":"Article 122374"},"PeriodicalIF":3.7,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142699322","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}
Pub Date : 2024-11-17DOI: 10.1016/j.foreco.2024.122383
Chunyan Xu , Michael Förster , Philip Beckschäfer , Ulrike Talkner , Caroline Klinck , Birgit Kleinschmit
<div><div>Since 2018, severe droughts have affected a significant part of central Europe, causing premature leaf senescence in European beech (<em>Fagus sylvatica</em> L.). The correlation between the vitality of <em>Fagus sylvatica</em> L. and various geo-ecological and biological determinants (such as elevation, slope, aspect, tree age, and soil properties) concerning hydrological drought stress is still not well understood, especially when integrating multiple geographical datasets. In addition, the determination of crown condition by remote sensing and geo-ecological parameters is still under development; it would allow the assessment of an area-wide forest health status. Our analysis incorporated annual field data from the German National Forest Condition Survey (Waldzustandserhebung, WZE) as a response variable and employed geo-ecological parameters derived from a digital elevation model, soil properties and vegetation indices from a Sentinel-2 time series to explain and predict the crown defoliation of European beech throughout the drought-impacted period spanning 2016–2022 across the federal states Schleswig-Holstein, Lower Saxony, and Hesse of Germany. In a second step, the results of the modeling were used for mapping of crown defoliation in Hesse, Lower Saxony and Schleswig-Holstein. By employing Gradient Boosting Machines and Random Forest for regression analysis, the study uncovered the relationships between crown defoliation and the used predictors. Training was conducted on 80 % of the dataset, with the remaining 20 % serving as a test set for model validation. Regression findings based on static explanatory variable sets were improved by dynamic explanatory variables such as estimates of soil moisture, vegetation index metrics, and diameter at breast height. Furthermore, we identified key predictors for mapping crown defoliation of <em>Fagus sylvatica</em> L. and recommended using vegetation indices as additional predictors for future studies. The modeling results provided comparably accurate estimates compared to WZE estimates (R<sup>2</sup> of 0.794 and RMSE of 7.646 %) during testing. Topographic and static soil predictors were significant, with soil moisture being a particularly influential variable for model optimization. Based on the predicted crown defoliation, beech trees with low to moderate crown defoliation predominated in beech distribution areas across the examined federal states, while a small number of beech trees with high defoliation were identified mostly in South Lower Saxony and Hesse. The annual variations in the proportions of beech trees showing increasing and decreasing crown defoliation indicate that the condition of the crown temporarily deteriorated when soil moisture decreased, but beech trees recovered after prolonged periods of drought. Additionally, beech trees in the study region exposed to declining soil moisture may suffer from medium-term declines in vitality. The predicted crown defoliation data
{"title":"Modeling European beech defoliation at a regional scale gradient in Germany from northern lowlands to central uplands using geo-ecological parameters, Sentinel-2 and National Forest Condition Survey data","authors":"Chunyan Xu , Michael Förster , Philip Beckschäfer , Ulrike Talkner , Caroline Klinck , Birgit Kleinschmit","doi":"10.1016/j.foreco.2024.122383","DOIUrl":"10.1016/j.foreco.2024.122383","url":null,"abstract":"<div><div>Since 2018, severe droughts have affected a significant part of central Europe, causing premature leaf senescence in European beech (<em>Fagus sylvatica</em> L.). The correlation between the vitality of <em>Fagus sylvatica</em> L. and various geo-ecological and biological determinants (such as elevation, slope, aspect, tree age, and soil properties) concerning hydrological drought stress is still not well understood, especially when integrating multiple geographical datasets. In addition, the determination of crown condition by remote sensing and geo-ecological parameters is still under development; it would allow the assessment of an area-wide forest health status. Our analysis incorporated annual field data from the German National Forest Condition Survey (Waldzustandserhebung, WZE) as a response variable and employed geo-ecological parameters derived from a digital elevation model, soil properties and vegetation indices from a Sentinel-2 time series to explain and predict the crown defoliation of European beech throughout the drought-impacted period spanning 2016–2022 across the federal states Schleswig-Holstein, Lower Saxony, and Hesse of Germany. In a second step, the results of the modeling were used for mapping of crown defoliation in Hesse, Lower Saxony and Schleswig-Holstein. By employing Gradient Boosting Machines and Random Forest for regression analysis, the study uncovered the relationships between crown defoliation and the used predictors. Training was conducted on 80 % of the dataset, with the remaining 20 % serving as a test set for model validation. Regression findings based on static explanatory variable sets were improved by dynamic explanatory variables such as estimates of soil moisture, vegetation index metrics, and diameter at breast height. Furthermore, we identified key predictors for mapping crown defoliation of <em>Fagus sylvatica</em> L. and recommended using vegetation indices as additional predictors for future studies. The modeling results provided comparably accurate estimates compared to WZE estimates (R<sup>2</sup> of 0.794 and RMSE of 7.646 %) during testing. Topographic and static soil predictors were significant, with soil moisture being a particularly influential variable for model optimization. Based on the predicted crown defoliation, beech trees with low to moderate crown defoliation predominated in beech distribution areas across the examined federal states, while a small number of beech trees with high defoliation were identified mostly in South Lower Saxony and Hesse. The annual variations in the proportions of beech trees showing increasing and decreasing crown defoliation indicate that the condition of the crown temporarily deteriorated when soil moisture decreased, but beech trees recovered after prolonged periods of drought. Additionally, beech trees in the study region exposed to declining soil moisture may suffer from medium-term declines in vitality. The predicted crown defoliation data","PeriodicalId":12350,"journal":{"name":"Forest Ecology and Management","volume":"576 ","pages":"Article 122383"},"PeriodicalIF":3.7,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656423","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}
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