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Fischer R, Zhunusova E, Günter S, Iost S, Schier F, Schweinle J, Weimar H, Dieter M. Leakage of biodiversity risks under the European Union Biodiversity Strategy 2030. Conserv Biol 2023:e14235. [PMID: 38155500 DOI: 10.1111/cobi.14235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 08/15/2023] [Accepted: 10/31/2023] [Indexed: 12/30/2023]
Abstract
The European Union Biodiversity Strategy 2030 (EUBDS) aims to regain biodiversity through enhanced forest conservation and protection, which may lead to increased timber harvest in non-EU countries. We aimed to identify the potential leakage of biodiversity risks as induced by the EUBDS. We created an indicator framework that allows one to quantify vulnerability of forest biodiversity. The framework is based on 26 biodiversity indicators for which indicator values were publicly available. We weighted single indicator values with countrywise modeled data on changed timber production under EUBDS implementation. Nearly 80% of the indicators pointed to higher vulnerability in the affected non-EU countries. Roundwood production was transferred to countries with, on average, lower governance quality (p = 0.0001), political awareness (p = 0.548), forest coverage (p = 0.034), and biomass (p = 0.272) and with less sustainable forest management (p = 0.044 and p = 0.028). These countries had more natural habitats (p = 0.039) and intact forest landscapes (p = 0.0001) but higher risk of species extinction (p = 0.006) and less protected area (p = 0.0001) than the EU countries. Only a few indicators pointed to lower vulnerability and biodiversity risks outside the EU. Safeguards are needed to ensure that implementation of EUBDS does not cause harm to ecosystems elsewhere. The EU regulation on deforestation-free supply chains might have limited effects because the sustainable management of existing and even expanding forests is not well considered. Sustained roundwood production in the EU is needed to avoid placing more pressure on more vulnerable ecosystems elsewhere. Decreasing species and habitat indicator values nevertheless call for global conservation and protection schemes. The EUBDS helped pave the way to the Kunming-Montreal Biodiversity Framework. Yet, lower values for the indicators mean governance and biodiversity engagement in non-EU countries suggest that this global framework might not sufficiently prevent leakage of risks to biodiversity. Effective land-use planning is necessary to balance conservation schemes with roundwood production.
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Affiliation(s)
- Richard Fischer
- Thünen Institute of Forestry, Forestry Worldwide Unit, Hamburg, Germany
| | - Eliza Zhunusova
- Thünen Institute of Forestry, Forestry Worldwide Unit, Hamburg, Germany
| | - Sven Günter
- Thünen Institute of Forestry, Forestry Worldwide Unit, Hamburg, Germany
| | - Susanne Iost
- Thünen Institute of Forestry, Forestry Worldwide Unit, Hamburg, Germany
| | - Franziska Schier
- Thünen Institute of Forestry, Forestry Worldwide Unit, Hamburg, Germany
| | - Jörg Schweinle
- Thünen Institute of Forestry, Forestry Worldwide Unit, Hamburg, Germany
| | - Holger Weimar
- Thünen Institute of Forestry, Forestry Worldwide Unit, Hamburg, Germany
| | - Matthias Dieter
- Thünen Institute of Forestry, Forestry Worldwide Unit, Hamburg, Germany
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Nath AJ, Reang D, Sileshi GW. The Shifting Cultivation Juggernaut: An Attribution Problem. Glob Chall 2022; 6:2200051. [PMID: 35958829 PMCID: PMC9360341 DOI: 10.1002/gch2.202200051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 05/06/2022] [Indexed: 06/15/2023]
Abstract
Shifting cultivation entails clearing a delimited land and transforming it into arable land. Owing to its complexity, this system has been a subject of debate and intervention since the colonial-era, and is often considered as the "tropical deforestation culprit." Shifting cultivators are often labeled as "forest eaters" and are considered backward and primitive. Opponents of shifting cultivation often attribute the loss of forest cover to shifting cultivation, and favor intensification, claiming that commercial plantations are more productive. However, attempts to replace it have often failed due to inadequate understanding of the system and the decision-making processes involved. On the other hand, a growing body of literature provides evidence that shifting cultivation is an ecologically and economically efficient practice. After a careful review of the literature, the authors conclude that the dichotomy of opinions is the consequence of the attribution problem. The authors also argue that the management of forest ecosystems will be challenging if policy and practice are not based on careful understanding of the power of this age-old practice. Hence, there is a need for a careful diagnosis of this system and a rethink before claiming that the system is unsustainable and attempting to replace it with practices such as plantations.
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Affiliation(s)
- Arun Jyoti Nath
- Department of Ecology and Environmental ScienceAssam UniversitySilchar788011India
| | - Demsai Reang
- Department of Ecology and Environmental ScienceAssam UniversitySilchar788011India
| | - Gudeta W. Sileshi
- Department of Plant Biology and Biodiversity ManagementAddis Ababa3434Ethiopia
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3
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Gómez-González S, Paniw M, Blanco-Pastor JL, García-Cervigón AI, Godoy O, Herrera JM, Lara A, Miranda A, Ojeda F, Ochoa-Hueso R. Moving towards the ecological intensification of tree plantations. Trends Plant Sci 2022; 27:637-645. [PMID: 35039247 DOI: 10.1016/j.tplants.2021.12.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Revised: 11/19/2021] [Accepted: 12/10/2021] [Indexed: 06/14/2023]
Abstract
The growing demand for timber and the boom in massive tree-planting programs could mean the spreading of mismanaged tree plantations worldwide. Here, we apply the concept of ecological intensification to forestry systems as a viable biodiversity-focused strategy that could be critical to develop productive, yet sustainable, tree plantations. Tree plantations can be highly productive if tree species are properly combined to complement their ecological functions. Simultaneously considering soil biodiversity and animal-mediated biocontrol will be critical to minimize the reliance on external inputs. Integrating genetic, functional, and demographic diversity across heterogeneous landscapes should improve resilience under climate change. Designing ecologically intensified plantations will mean breaking the timber productivity versus conservation dichotomy and assuring the maintenance of key ecosystem services at safe levels.
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Affiliation(s)
- Susana Gómez-González
- Departamento de Biología-IVAGRO, Universidad de Cádiz, Campus Río San Pedro, 11510 Puerto Real, Spain; Center for Climate and Resilience Research (CR)2, Blanco Encalada 2002, 8370449 Santiago, Chile; Center for Fire and Socioecological Systems (FireSES), Universidad Austral de Chile, Campus Isla Teja, 5090000 Valdivia, Chile.
| | - Maria Paniw
- Department of Conservation Biology and Global Change, Estación Biológica de Doñana (EBD-CSIC), Avenida Americo Vespucio 26, 41092 Sevilla, Spain
| | - José Luis Blanco-Pastor
- Department of Plant Biology and Ecology, University of Seville, Avenida Reina Mercedes 6, 41012 Seville, Spain
| | - Ana I García-Cervigón
- Biodiversity and Conservation Area, Rey Juan Carlos University, c/ Tulipán s/n, 28933 Móstoles, Spain
| | - Oscar Godoy
- Instituto Universitario de Investigación Marina (INMAR), Departamento de Biología, Universidad de Cádiz, Campus Río San Pedro, 11510 Puerto Real, Spain
| | - José M Herrera
- Mediterranean Institute for Agriculture, Environment and Development and University of Évora, Casa Cordovil, 2nd Floor, R. Dom Augusto Eduardo Nunes 7, 7000 - 651 Évora, Portugal
| | - Antonio Lara
- Center for Climate and Resilience Research (CR)2, Blanco Encalada 2002, 8370449 Santiago, Chile; Instituto de Conservación, Biodiversidad y Territorio, Universidad Austral de Chile, Campus Isla Teja, 5090000 Valdivia, Chile; Fundación Centro de los Bosques Nativos Forecos, Valdivia, Chile
| | - Alejandro Miranda
- Center for Climate and Resilience Research (CR)2, Blanco Encalada 2002, 8370449 Santiago, Chile; Laboratorio de Ecología del Paisaje y Conservación, Departamento de Ciencias Forestales, Universidad de La Frontera, P.O. Box 54-D, 4780000 Temuco, Chile
| | - Fernando Ojeda
- Departamento de Biología-IVAGRO, Universidad de Cádiz, Campus Río San Pedro, 11510 Puerto Real, Spain
| | - Raúl Ochoa-Hueso
- Departamento de Biología-IVAGRO, Universidad de Cádiz, Campus Río San Pedro, 11510 Puerto Real, Spain; Department of Terrestrial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), P.O. Box 50, 6700 AB, Wageningen, The Netherlands
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Nunes LJR, Meireles CIR, Gomes CJP, Ribeiro NMCA. The Impact of Climate Change on Forest Development: A Sustainable Approach to Management Models Applied to Mediterranean-Type Climate Regions. Plants (Basel) 2021; 11:plants11010069. [PMID: 35009073 PMCID: PMC8747560 DOI: 10.3390/plants11010069] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 12/22/2021] [Accepted: 12/23/2021] [Indexed: 05/22/2023]
Abstract
Forest ecosystems are divided into three major groups: boreal, temperate, and tropical. These can be subdivided according to the particularities of each type due to its relative location (littoral, mountain, etc.), climatic conditions, or even geological substrate. Climate change affects each type of forest ecosystem differently. However, it seems to affect temperate forests in Mediterranean-type climate regions more intensely. These regions are located over several continents, with major impacts of increased temperature during summer and decreased precipitation during winter. This situation affects Mediterranean forest ecosystems by increasing the risk of fires, which arise more frequently and are more severe. In addition, the emergence of pests and the spread of invasive species are well-known problems affecting these ecosystems. All of these conditions contribute to losses of productivity and biodiversity. To avoid the destruction of forest resources, and since Mediterranean-type climate regions are considered climate change hot spots with increased vulnerability to disturbances, the implementation of adaptive forest management models could contribute to increasing the resilience of such forests, which could also contribute to mitigating climate change.
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Affiliation(s)
- Leonel J. R. Nunes
- PROMETHEUS—Unidade de Investigação em Materiais, Energia e Ambiente para a Sustentabilidade, Escola Superior Agrária, Instituto Politécnico de Viana do Castelo, Rua da Escola Industrial e Comercial de Nun’Alvares, 4900-347 Viana do Castelo, Portugal
- Correspondence:
| | - Catarina I. R. Meireles
- MED—Mediterranean Institute for Agriculture, Environment and Development, Pólo da Mitra, Universidade de Évora, 7006-554 Evora, Portugal; (C.I.R.M.); (C.J.P.G.)
| | - Carlos J. Pinto Gomes
- MED—Mediterranean Institute for Agriculture, Environment and Development, Pólo da Mitra, Universidade de Évora, 7006-554 Evora, Portugal; (C.I.R.M.); (C.J.P.G.)
- Departamento da Paisagem, Ambiente e Ordenamento, Universidade de Évora, 7000-671 Evora, Portugal
| | - Nuno M. C. Almeida Ribeiro
- ICT—Instituto de Ciências da Terra, Universidade de Évora, Rua Romão Ramalho, 59, 7002-554 Evora, Portugal;
- Departamento de Fitotecnia, Universidade de Évora, 7000-083 Evora, Portugal
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Li Y, Li M, Li X, Liu Z, Ming A, Lan H, Ye S. The Abundance and Structure of Deadwood: A Comparison of Mixed and Thinned Chinese Fir Plantations. Front Plant Sci 2021; 12:614695. [PMID: 33746997 PMCID: PMC7965984 DOI: 10.3389/fpls.2021.614695] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Accepted: 02/05/2021] [Indexed: 06/12/2023]
Abstract
The sustainability of coniferous monoculture plantations is facing challenges with respect to yields, ecology, and biodiversity. Conversion of monocultural coniferous plantations into mixed stands using thinning or direct mixed planting is widely considered to be a key strategy for overcoming these challenges and transforming the characteristics of plantations on a regional scale. Substantial amounts of deadwood may be produced in mixed forests (MFs); this material is important for evaluating and modifying forest management methods, understanding the dynamics of forest stands, and achieving biodiversity conservation. We assessed the quantitative characters and diameter distributions of deadwood in mixed and thinned Chinese fir [Cunninghamia lanceolata (Lamb.) Hook.] forests over one rotation. We used the g(r) function and spatial parameters to analyze the spatial structure of deadwood, and used logistic regression and Hegyi's competition index (HCI) to explore competition and mortality. Our results indicate that: (1) Chinese fir dominated in all groups of deadwood (snags, broken wood, and fallen wood), and the abundance, volume, and mortality rates of deadwood were much lower in the thinning forest compared to the MF. (2) Later coming populations (LCPs) comprised the majority of the small diameter classes in the thinning forest, but only accounted for a small proportion of the MF. (3) Broken wood in the thinning forest was randomly distributed, while the other types of deadwood were clustered at most spatial scales. In contrast, the spatial patterns in the MF were random at most spatial scales. (4) Total deadwood in both stands was in a status of intermediate and was randomly surrounded by its four nearest neighbors. All types of deadwood were highly mixed in the thinning forest and moderately mixed in the MF. Our case study suggests that thinning and mixing result in different stand development processes and thus influence the type, amount, and structure of deadwood. Thinning significantly reduces competition, which is the main driver of tree mortality. Converting pure Chinese fir plantations into mixed stands by thinning should be taken in future. Understanding tree mortality after conversion is essential to select appropriate silvicultural treatments and achieve ultimately sustainable forest management.
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Affiliation(s)
- Yuanfa Li
- College of Forestry, Guangxi Key Laboratory of Forest Ecology and Conservation, Guangxi University, Nanning, China
- Department of Renewable Resources, University of Alberta, Edmonton, AB, Canada
| | - Muxuan Li
- College of Forestry, Guangxi Key Laboratory of Forest Ecology and Conservation, Guangxi University, Nanning, China
| | - Xian Li
- College of Forestry, Guangxi Key Laboratory of Forest Ecology and Conservation, Guangxi University, Nanning, China
| | - Zhilong Liu
- Experimental Center of Tropical Forestry, Chinese Academy of Forestry, Pingxiang, China
- Guangxi Youyiguan Forest Ecosystem Research Station, Pingxiang, China
| | - Angang Ming
- Experimental Center of Tropical Forestry, Chinese Academy of Forestry, Pingxiang, China
- Guangxi Youyiguan Forest Ecosystem Research Station, Pingxiang, China
| | - Huangxu Lan
- Experimental Center of Tropical Forestry, Chinese Academy of Forestry, Pingxiang, China
| | - Shaoming Ye
- College of Forestry, Guangxi Key Laboratory of Forest Ecology and Conservation, Guangxi University, Nanning, China
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Marquis B, Bergeron Y, Simard M, Tremblay F. Growing-season frost is a better predictor of tree growth than mean annual temperature in boreal mixedwood forest plantations. Glob Chang Biol 2020; 26:6537-6554. [PMID: 32865303 DOI: 10.1111/gcb.15327] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 06/16/2020] [Accepted: 07/12/2020] [Indexed: 06/11/2023]
Abstract
Increase in frost damage to trees due to earlier spring dehardening could outweigh the expected increase in forest productivity caused by climate warming. We quantified the impact of growing-season frosts on the performance of three spruce species (white, black, and Norway spruce) and various seed sources with different frost tolerance in two plantations, established on both sides of the eastern Canadian boreal-temperate forest ecotone. The objectives of this study were to determine (a) if spruce species and seed sources planted in sites far from their natural provenance would be less adapted to local site conditions, leading to increased frost damage and reduced height growth; (b) at which height above the ground growing-season frosts ceased to damage apical meristems; and (c) if height growth was best predicted by extreme climatic events (growing-season frosts) or by mean annual or summer temperature. At each site and for all spruce species and seed sources, we cross-sectioned spruce trees at different heights above the ground. Tree rings were cross-dated and screened for frost rings, which were then given a severity score based on cellular damage. Frost severity reduced height growth of all spruce species and provenances at both sites. Height growth of the non-native Norway spruce was the most reduced by frost severity and was the smallest species at both sites. Frost caused the highest growth reduction in white spruce at the boreal mixedwood site and had the least effect on black spruce at both sites. For all spruce species, height growth was affected up to 2 m above the ground. Model selection based on corrected Akaike's information criteria (AICc) identified that minimum temperature in May was by far the best climate variable predicting tree growth (AICc weight = 1), highlighting the importance of considering extreme climatic events, which are likely to increase in the future.
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Affiliation(s)
- Benjamin Marquis
- Institut de Recherche sur les Forêts, Université du Québec en Abitibi Témiscamingue, Rouyn-Noranda, QC, Canada
| | - Yves Bergeron
- Institut de Recherche sur les Forêts, Université du Québec en Abitibi Témiscamingue, Rouyn-Noranda, QC, Canada
- Département des sciences Biologiques, Université du Québec à Montréal, Montréal, QC, Canada
| | - Martin Simard
- Department of Geography, Center for Forest Research, Laval University, Québec, QC, Canada
- Center for Northern Studies, Laval University, Québec, QC, Canada
| | - Francine Tremblay
- Institut de Recherche sur les Forêts, Université du Québec en Abitibi Témiscamingue, Rouyn-Noranda, QC, Canada
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Ming A, Yang Y, Liu S, Nong Y, Tao Y, Zeng J, An N, Niu C, Zhao Z, Jia H, Cai D. A Decade of Close-to-Nature Transformation Alters Species Composition and Increases Plant Community Diversity in Two Coniferous Plantations. Front Plant Sci 2020; 11:1141. [PMID: 32849700 PMCID: PMC7396570 DOI: 10.3389/fpls.2020.01141] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/26/2020] [Accepted: 07/14/2020] [Indexed: 06/11/2023]
Abstract
Close-to-nature transformation silviculture is a promising approach to meet the criteria for sustainable forestry. To explore the effects of close-to-nature transformation on community structure and plant diversity in Pinus massoniana and Cunninghamia lanceolatas pure plantations, four stands were selected, including close-to-nature transformed stand of P. massoniana (PCN) and its unimproved pure stand (PCK), and close-to-nature transformed stand of C. lanceolata (CCN) and its unimproved pure stand (CCK). Plant diversity and community structure in the four stands were investigated before and after a decade of close-to-nature transformation. After the close-to-nature transformation, the plant diversity and community structure were significantly altered. Compared with control stands, the transformation increased the species richness and diversity of the tree layer and the whole community, while did not significantly affected the shrub and herb diversity. The species richness in the tree layer in the P. massoniana and C. lanceolata plantations was 2.1 and 2.8 times that of their corresponding control. Species composition and important value of each species were altered in the tree, shrub and herb layers. The close-to-natural transformation lowered the community dominance and the important value of P. massoniana and C. lanceolate. The advantage position of single species in the community was weakened by the forest transformation. The plant community became diversified and uniformly distributed. The enhanced community species diversity was derived from the increase in the tree diversity. These results indicated that close-to-nature transformation increased the forest plant diversity and optimized the community structure. The close-to-nature transformation plays a positive role in coniferous plantation ecosystem structure.
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Affiliation(s)
- Angang Ming
- Experimental Center of Tropical Forestry, Chinese Academy of Forestry, Guangxi Youyiguan Forest Ecosystem Research Station, Pingxiang, China
| | - Yujing Yang
- Hubei Key Laboratory of Regional Development and Environmental Response, Faculty of Resources and Environmental Sciences, Hubei University, Wuhan, China
| | - Shirong Liu
- Key Laboratory of Forest Ecology and Environment, State Forestry Administration, Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing, China
| | - You Nong
- Experimental Center of Tropical Forestry, Chinese Academy of Forestry, Guangxi Youyiguan Forest Ecosystem Research Station, Pingxiang, China
| | - Yi Tao
- Experimental Center of Tropical Forestry, Chinese Academy of Forestry, Guangxi Youyiguan Forest Ecosystem Research Station, Pingxiang, China
| | - Ji Zeng
- Experimental Center of Tropical Forestry, Chinese Academy of Forestry, Guangxi Youyiguan Forest Ecosystem Research Station, Pingxiang, China
| | - Ning An
- Experimental Center of Tropical Forestry, Chinese Academy of Forestry, Guangxi Youyiguan Forest Ecosystem Research Station, Pingxiang, China
| | - Changhai Niu
- Experimental Center of Tropical Forestry, Chinese Academy of Forestry, Guangxi Youyiguan Forest Ecosystem Research Station, Pingxiang, China
| | - Zhang Zhao
- Experimental Center of Tropical Forestry, Chinese Academy of Forestry, Guangxi Youyiguan Forest Ecosystem Research Station, Pingxiang, China
| | - Hongyan Jia
- Experimental Center of Tropical Forestry, Chinese Academy of Forestry, Guangxi Youyiguan Forest Ecosystem Research Station, Pingxiang, China
| | - Daoxiong Cai
- Experimental Center of Tropical Forestry, Chinese Academy of Forestry, Guangxi Youyiguan Forest Ecosystem Research Station, Pingxiang, China
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Devaney JL, Pullen J, Cook-Patton SC, Burghardt KT, Parker JD. Tree diversity promotes growth of late successional species despite increasing deer damage in a restored forest. Ecology 2020; 101:e03063. [PMID: 32239510 DOI: 10.1002/ecy.3063] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 02/07/2020] [Accepted: 02/24/2020] [Indexed: 11/09/2022]
Abstract
The role of tree diversity in restored forests and its impact on key ecological processes like growth and resistance to herbivory has become increasingly important. We analyzed height growth and white-tailed deer Odocoileus virginianus browsing damage to saplings of 16 broadleaved tree species in a large-scale (13 ha) reforestation experiment in Maryland, USA, where we manipulated tree diversity in 70 1,225-m2 plots. After four growing seasons, higher plot-level tree richness led to increased deer browsing damage (i.e., associational susceptibility). Despite increased deer damage to saplings in mixed plots, tree richness had no overall effect on sapling height growth. However, diversity-height relationships were related to species functional traits. Light demanding species with large leaves and faster growth rates had reduced heights in mixtures, whereas shade-tolerant, slower-growing species generally had either increased or unchanged height growth in diverse tree communities, likely related to increased canopy closure in mixtures relative to monocultures. We show that tree diversity can improve growth of late successional species despite exacerbated mammalian herbivore damage. By facilitating the establishment of species with a range of life-history strategies, increased tree diversity may enhance ecosystem multi-functionality in the early stages of forest restoration.
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Affiliation(s)
- John L Devaney
- Botany Department, Trinity College Dublin, The University of Dublin, Dublin, 2, Ireland.,Smithsonian Environmental Research Center, Edgewater, Maryland, 21037, USA
| | - Jamie Pullen
- Smithsonian Environmental Research Center, Edgewater, Maryland, 21037, USA
| | - Susan C Cook-Patton
- Smithsonian Environmental Research Center, Edgewater, Maryland, 21037, USA.,The Nature Conservancy, Arlington, Virginia, 22203, USA
| | - Karin T Burghardt
- Smithsonian Environmental Research Center, Edgewater, Maryland, 21037, USA.,Department of Entomology, University of Maryland-College Park, College Park, Maryland, 20742, USA
| | - John D Parker
- Smithsonian Environmental Research Center, Edgewater, Maryland, 21037, USA
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Lindenmayer DB, Taylor C. New spatial analyses of Australian wildfires highlight the need for new fire, resource, and conservation policies. Proc Natl Acad Sci U S A 2020; 117:12481-5. [PMID: 32424092 DOI: 10.1073/pnas.2002269117] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Extensive and recurrent severe wildfires present complex challenges for policy makers. This is highlighted by extensive wildfires around the globe, ranging from western North America and Europe to the Amazon and Arctic, and, most recently, the 2019-2020 fires in eastern Australia. In many jurisdictions, discussions after significant losses of life, property, and vegetation are sometimes conducted in the absence of nuanced debates about key aspects of climate, land, and resource management policy. Improved insights that have significant implications for policies and management can be derived from spatial and temporal analyses of fires. Here, we demonstrate the importance of such analyses using a case study of large-scale, recurrent severe wildfires over the past two decades in the Australian state of Victoria. We overlaid the location of current and past fires with ecosystem types, land use, and conservation values. Our analyses revealed 1) the large spatial extent of current fires, 2) the extensive and frequent reburning of recently and previously fire-damaged areas, 3) the magnitude of resource loss for industries such as timber and pulplog production, and 4) major impacts on high conservation value areas and biodiversity. These analyses contain evidence to support policy reforms that alter the mode of forest management, target the protection of key natural assets including unburnt areas, manage repeatedly damaged and potentially collapsed ecosystems, and expand the conservation estate. Our mapping approach should have applicability to other environments subject to large-scale fires, although the particular details of policy reforms would be jurisdiction, ecosystem, and context specific.
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Roopsind A, Caughlin TT, van der Hout P, Arets E, Putz FE. Trade-offs between carbon stocks and timber recovery in tropical forests are mediated by logging intensity. Glob Chang Biol 2018; 24:2862-2874. [PMID: 29603495 DOI: 10.1111/gcb.14155] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2017] [Revised: 02/22/2018] [Accepted: 03/12/2018] [Indexed: 06/08/2023]
Abstract
Forest degradation accounts for ~70% of total carbon losses from tropical forests. Substantial emissions are from selective logging, a land-use activity that decreases forest carbon density. To maintain carbon values in selectively logged forests, climate change mitigation policies and government agencies promote the adoption of reduced-impact logging (RIL) practices. However, whether RIL will maintain both carbon and timber values in managed tropical forests over time remains uncertain. In this study, we quantify the recovery of timber stocks and aboveground carbon at an experimental site where forests were subjected to different intensities of RIL (4, 8, and 16 trees/ha). Our census data span 20 years postlogging and 17 years after the liberation of future crop trees from competition in a tropical forest on the Guiana Shield, a globally important forest carbon reservoir. We model recovery of timber and carbon with a breakpoint regression that allowed us to capture elevated tree mortality immediately after logging. Recovery rates of timber and carbon were governed by the presence of residual trees (i.e., trees that persisted through the first harvest). The liberation treatment stimulated faster recovery of timber albeit at a carbon cost. Model results suggest a threshold logging intensity beyond which forests managed for timber and carbon derive few benefits from RIL, with recruitment and residual growth not sufficient to offset losses. Inclusion of the breakpoint at which carbon and timber gains outpaced postlogging mortality led to high predictive accuracy, including out-of-sample R2 values >90%, and enabled inference on demographic changes postlogging. Our modeling framework is broadly applicable to studies that aim to quantify impacts of logging on forest recovery. Overall, we demonstrate that initial mortality drives variation in recovery rates, that the second harvest depends on old growth wood, and that timber intensification lowers carbon stocks.
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Affiliation(s)
- Anand Roopsind
- Biological Sciences, Boise State University, Boise, ID, USA
| | | | | | - Eric Arets
- Wageningen University and Research, Wageningen, The Netherlands
| | - Francis E Putz
- Department of Biology, University of Florida, Gainesville, FL, USA
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Correia DLP, Raulier F, Bouchard M, Filotas É. Response diversity, functional redundancy, and post-logging productivity in northern temperate and boreal forests. Ecol Appl 2018; 28:1282-1291. [PMID: 29672967 DOI: 10.1002/eap.1727] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Revised: 02/07/2018] [Accepted: 03/19/2018] [Indexed: 06/08/2023]
Abstract
The development of efficient ecosystem resilience indicators was identified as one of the key research priorities in the improvement of existing sustainable forest management frameworks. Two indicators of tree diversity associated with ecosystem functioning have recently received particular attention in the literature: functional redundancy (FR) and response diversity (RD). We examined how these indicators could be used to predict post-logging productivity in forests of Québec, Canada. We analysed the relationships between pre-logging FR and RD, as measured with sample plots, and post-logging productivity, measured as seasonal variation in enhanced vegetation index obtained from MODIS satellite imagery. The effects of the deciduous and coniferous tree components in our pre-disturbance diversity assessments were isolated in order to examine the hypothesis that they have different impacts on post-disturbance productivity. We also examined the role of tree species richness and species identity effects. Our analysis revealed the complementary nature of traditional biodiversity indicators and trait-based approaches in the study of biodiversity-ecosystem-functioning relationships in dynamic ecosystems. We report a significant and positive relationship between pre-disturbance deciduous RD and post-disturbance productivity, as well as an unexpected significant negative effect of coniferous RD on productivity. This negative relationship with post-logging productivity likely results from slower coniferous regeneration speeds and from the relatively short temporal scale examined. Negative black-spruce-mediated identity effects were likely associated with increased stand vulnerability to paludification and invasion by ericaceous shrubs that slow down forest regeneration. Response diversity outperformed functional redundancy as a measure of post-disturbance productivity most likely due to the stand-replacing nature of the disturbance considered. To the best of our knowledge, this is among the first studies to report a negative significant relationship between a component of RD and ecosystem functioning, namely coniferous RD and forest ecosystem productivity after a stand-replacing disturbance.
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Affiliation(s)
- David Laginha Pinto Correia
- Centre d'Étude de la Forêt and Faculté de foresterie, de géographie et de géomatique, Laval University, 2405 rue de la Terrasse, Québec, Quebec, G1V 0A6, Canada
| | - Frédéric Raulier
- Centre d'Étude de la Forêt and Faculté de foresterie, de géographie et de géomatique, Laval University, 2405 rue de la Terrasse, Québec, Quebec, G1V 0A6, Canada
| | - Mathieu Bouchard
- Direction de la recherche forestière, Ministère des Forêts, de la Faune et des Parcs, 2700, rue Einstein, Québec, Quebec, G1P 3W8, Canada
| | - Élise Filotas
- Centre for Forest Research (CFR), TELUQ, Université du Québec, Montréal, Quebec, H2S 3L5, Canada
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Montoro Girona M, Lussier JM, Morin H, Thiffault N. Conifer Regeneration After Experimental Shelterwood and Seed-Tree Treatments in Boreal Forests: Finding Silvicultural Alternatives. Front Plant Sci 2018; 9:1145. [PMID: 30174675 PMCID: PMC6108379 DOI: 10.3389/fpls.2018.01145] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2018] [Accepted: 07/17/2018] [Indexed: 05/15/2023]
Abstract
Forest regeneration is a key element in achieving sustainable forest management. Partial harvest methods have been used extensively in temperate broadleaf and mixedwood ecosystems to promote regeneration on poorly stocked sites and to maintain forest composition and productivity. However, their effectiveness in promoting conifer establishment has yet to be demonstrated in unmanaged boreal forests, especially those dominated by black spruce (Picea mariana (Mill.) BSP) where constraints for regeneration differ from those found in more meridional regions. We aimed to evaluate conifer seedling density and dimensions, 10 years after the onset of a gradient of silvicultural treatments varying in harvesting intensities, and to identify the critical factors driving the regeneration process. Study blocks of even-aged black spruce stands in the eastern Canadian boreal forest were submitted to three variants of shelterwood harvesting: a seed-tree harvest, a clear-cut and an untreated control. Shelterwood and seed-tree harvesting were combined with spot scarification to promote regeneration. Shelterwood and seed-tree harvesting produced a density of conifer regeneration sufficient to maintain forest productivity, but they did not promote seedling growth. Black spruce was the predominant species in terms of regeneration density, with proportions 3-5× higher than that for balsam fir (Abies balsamea (L.) Mill.). Ten years after treatment, seed-origin black spruce seedlings were abundant in skidding trails, while layers dominated the residual strips. Balsam fir density was not influenced by treatment nor by tree position relative to skidding trails. Balsam fir and black spruce had different responses to treatment in terms of height and diameter, the former exhibiting a better growth performance and larger diameter in the residual strips. Spot scarification created micro-sites that had a significant impact on the regeneration process. Overall, our results support that shelterwood and seed-tree harvesting combined with scarification enable adequate regeneration in black spruce stands, confirming these treatments as viable silvicultural alternatives to clear-cutting when required by sustainable forest management objectives.
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Affiliation(s)
- Miguel Montoro Girona
- Ecology Restoration Group, Department of Wildlife, Fish and Environmental Studies, Swedish University of Agricultural Sciences (SLU), Umeå, Sweden
- Département des Sciences Fondamentales, Université du Québec à Chicoutimi, Saguenay, QC, Canada
- *Correspondence: Miguel Montoro Girona
| | | | - Hubert Morin
- Département des Sciences Fondamentales, Université du Québec à Chicoutimi, Saguenay, QC, Canada
| | - Nelson Thiffault
- Canadian Wood Fibre Centre, Natural Resources Canada, Ottawa, QC, Canada
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13
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Navarro L, Morin H, Bergeron Y, Girona MM. Changes in Spatiotemporal Patterns of 20th Century Spruce Budworm Outbreaks in Eastern Canadian Boreal Forests. Front Plant Sci 2018; 9:1905. [PMID: 30622551 PMCID: PMC6308396 DOI: 10.3389/fpls.2018.01905] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Accepted: 12/07/2018] [Indexed: 05/15/2023]
Abstract
In scenarios of future climate change, there is a projectedincrease in the occurrence and severity of natural disturbances inboreal forests. Spruce budworm (Choristoneura fumiferana)(SBW) is the main defoliator of conifer trees in the North American boreal forests affecting large areas and causing marked losses of timber supplies. However, the impact and the spatiotemporal patterns of SBW dynamics at the landscape scale over the last century remain poorly known. This is particularly true for northern regions dominated by spruce species. The main goal of this study is to reconstruct SBW outbreaks during the 20th century at the landscape scale and to evaluate changes in the associated spatiotemporal patterns in terms of distribution area, frequency, and severity. We rely on a dendroecological approach from sites within the eastern Canadian boreal forest and draw from a large dataset of almost 4,000 trees across a study area of nearly 800,000 km2. Interpolation and analyses of hotspots determined reductions in tree growth related to insect outbreak periods and identified the spatiotemporal patterns of SBW activity over the last century. The use of an Ordinary Least Squares model including regional temperature and precipitation anomalies allows us to assess the impact of climate variables on growth reductions and to compensate for the lack of non-host trees in northern regions. We identified three insect outbreaks having different spatiotemporal patterns, duration, and severity. The first (1905-1930) affected up to 40% of the studied trees, initially synchronizing from local infestations and then migrating to northern stands. The second outbreak (1935-1965) was the longest and the least severe with only up to 30% of trees affected by SBW activity. The third event (1968-1988) was the shortest, yet it was also the most severe and extensive, affecting nearly up to 50% of trees and 70% of the study area. This most recent event was identified for the first time at the limit of the commercial forest illustrating a northward shift of the SBW distribution area during the 20th century. Overall, this research confirms that insect outbreaks are a complex and dynamic ecological phenomena, which makes the understanding of natural disturbance cycles at multiple scales a major priority especially in the context of future regional climate change.
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Affiliation(s)
- Lionel Navarro
- Département des Sciences Fondamentales, Université du Québec à Chicoutimi, Saguenay, QC, Canada
| | - Hubert Morin
- Département des Sciences Fondamentales, Université du Québec à Chicoutimi, Saguenay, QC, Canada
| | - Yves Bergeron
- Chaire Industrielle CRSNG-UQAT-UQAM En Aménagement Forestier Durable, Institut de Recherche sur les Forêts, Université du Québec en Abitibi-Témiscamingue, Rouyn-Noranda, QC, Canada
| | - Miguel Montoro Girona
- Département des Sciences Fondamentales, Université du Québec à Chicoutimi, Saguenay, QC, Canada
- Ecology Restoration Group, Department of Wildlife, Fish and Environmental Studies, Swedish University of Agricultural Sciences (SLU), Umeå, Sweden
- *Correspondence: Miguel Montoro Girona, ;
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14
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Cosset CCP, Edwards DP. The effects of restoring logged tropical forests on avian phylogenetic and functional diversity. Ecol Appl 2017; 27:1932-1945. [PMID: 28543995 DOI: 10.1002/eap.1578] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 05/11/2017] [Accepted: 05/16/2017] [Indexed: 06/07/2023]
Abstract
Selective logging is the most prevalent land-use change in the tropics. Despite the resulting degradation of forest structure, selectively logged forests still harbor a substantial amount of biodiversity leading to suggestions that their protection is the next best alternative to conserving primary, old-growth forests. Restoring carbon stocks under Reducing Emissions from Deforestation and Forest Degradation (REDD+) schemes is a potential method for obtaining funding to protect logged forests, via enrichment planting and liberation cutting of vines. This study investigates the impacts of restoring logged forests in Borneo on avian phylogenetic diversity, the total evolutionary history shared across all species within a community, and on functional diversity, with important implications for the protection of evolutionarily unique species and the provision of many ecosystem services. Overall and understorey avifaunal communities were studied using point count and mist netting surveys, respectively. Restoration caused a significant loss in phylogenetic diversity and MPD (mean pairwise distance) leaving an overall bird community of less total evolutionary history and more closely related species compared to unlogged forests, while the understorey bird community had MNTD (mean nearest taxon distance) that returned toward the lower levels found in a primary forest, indicating more closely related species pairs. The overall bird community experienced a significant loss of functional strategies and species with more specialized traits in restored forests compared to that of unlogged forests, which led to functional clustering in the community. Restoration also led to a reduction in functional richness and thus niches occupied in the understorey bird community compared to unlogged forests. While there are additional benefits of restoration for forest regeneration, carbon sequestration, future timber harvests, and potentially reduced threat of forest conversion, this must be weighed against the apparent loss of phylogenetic and functional diversity from unlogged forest levels, making the biodiversity-friendliness of carbon sequestration schemes questionable under future REDD+ agreements. To reduce perverse biodiversity outcomes, it is important to focus restoration only on the most degraded areas or at reduced intensity where breaks between regimes are incorporated.
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Affiliation(s)
- Cindy C P Cosset
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield, S10 2TN, United Kingdom
| | - David P Edwards
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield, S10 2TN, United Kingdom
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15
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Kleinschroth F, Healey JR, Gourlet-Fleury S, Mortier F, Stoica RS. Effects of logging on roadless space in intact forest landscapes of the Congo Basin. Conserv Biol 2017; 31:469-480. [PMID: 27565760 DOI: 10.1111/cobi.12815] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Revised: 08/11/2016] [Accepted: 08/15/2016] [Indexed: 06/06/2023]
Abstract
Forest degradation in the tropics is often associated with roads built for selective logging. The protection of intact forest landscapes (IFL) that are not accessible by roads is high on the biodiversity conservation agenda and a challenge for logging concessions certified by the Forest Stewardship Council (FSC). A frequently advocated conservation objective is to maximize the retention of roadless space, a concept that is based on distance to the nearest road from any point. We developed a novel use of the empty-space function - a general statistical tool based on stochastic geometry and random sets theory - to calculate roadless space in a part of the Congo Basin where road networks have been expanding rapidly. We compared the temporal development of roadless space in certified and uncertified logging concessions inside and outside areas declared IFL in 2000. Inside IFLs, road-network expansion led to a decrease in roadless space by more than half from 1999 to 2007. After 2007, loss leveled out in most areas to close to 0 due to an equilibrium between newly built roads and abandoned roads that became revegetated. However, concessions in IFL certified by FSC since around 2007 continuously lost roadless space and reached a level comparable to all other concessions. Only national parks remained mostly roadless. We recommend that forest-management policies make the preservation of large connected forest areas a top priority by effectively monitoring - and limiting - the occupation of space by roads that are permanently accessible.
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Affiliation(s)
- Fritz Kleinschroth
- CIRAD, Forêts et Sociétés, 34398, Montpellier, France
- Bangor University, School of Environment, Natural Resources and Geography, Bangor, Gwynedd, LL57 2UW, U.K
| | - John R Healey
- Bangor University, School of Environment, Natural Resources and Geography, Bangor, Gwynedd, LL57 2UW, U.K
| | | | | | - Radu S Stoica
- Université de Lorraine, Institut Élie Cartan de Lorraine, 54506, Vandoeuvre-lès-Nancy Cedex, France
- Institut de Mécanique Céleste et de Calcul des Éphémérides, Observatoire de Paris, 75014, Paris, France
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16
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Bernier PY, Paré D, Stinson G, Bridge SRJ, Kishchuk BE, Lemprière TC, Thiffault E, Titus BD, Vasbinder W. Moving beyond the concept of "primary forest" as a metric of forest environment quality. Ecol Appl 2017; 27:349-354. [PMID: 27930833 DOI: 10.1002/eap.1477] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Revised: 10/31/2016] [Accepted: 11/30/2016] [Indexed: 06/06/2023]
Abstract
The United Nations Food and Agriculture Organization (FAO) has been reporting country-level area in primary forests in its Global Forest Resource Assessment since 2005. The FAO definition of a primary forest (naturally regenerated forest of native species where there are no clearly visible indications of human activities and the ecological processes are not significantly disturbed) is generally accepted as authoritative and is being used in policy making. However, problems with this definition undermine our capacity to obtain globally coherent estimates. In addition, the current reporting on primary forests fails to consider the complementarily of non-primary forests toward the maintenance of ecosystem services. These issues undermine the appropriate tracking of changes in primary and non-primary forests, and the assessment of impacts of such changes on ecosystem services. We present the case for an operational reconsideration of the primary forest concept and discuss how alternatives or supplements might be developed.
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Affiliation(s)
- P Y Bernier
- Natural Resources Canada, Canadian Forest Service, PO Box 10380 Stn. Ste-Foy, Quebec, QC, G1V 4C7, Canada
| | - D Paré
- Natural Resources Canada, Canadian Forest Service, PO Box 10380 Stn. Ste-Foy, Quebec, QC, G1V 4C7, Canada
| | - G Stinson
- Natural Resources Canada, Canadian Forest Service, 506 West Burnside Road, Victoria, BC, V8Z 1M5, Canada
| | - S R J Bridge
- Natural Resources Canada, Canadian Forest Service, 580 Booth Street, Ottawa, ON, K1A 0E4, Canada
| | - B E Kishchuk
- Natural Resources Canada, Canadian Forest Service, 580 Booth Street, Ottawa, ON, K1A 0E4, Canada
| | - T C Lemprière
- Natural Resources Canada, Canadian Forest Service, 55 St. Clair Avenue East, Toronto, ON, M4T 1M2, Canada
| | - E Thiffault
- Department of Wood and and Forest Sciences, Laval University, 2405 Rue de la Terrasse, Quebec, QC, G1V 0A6, Canada
| | - B D Titus
- Natural Resources Canada, Canadian Forest Service, 506 West Burnside Road, Victoria, BC, V8Z 1M5, Canada
| | - W Vasbinder
- Natural Resources Canada, Canadian Forest Service, 580 Booth Street, Ottawa, ON, K1A 0E4, Canada
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Bicknell JE, Struebig MJ, Davies ZG, Baraloto C. Reconciling timber extraction with biodiversity conservation in tropical forests using reduced-impact logging. J Appl Ecol 2015; 52:379-388. [PMID: 25954054 PMCID: PMC4415554 DOI: 10.1111/1365-2664.12391] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Accepted: 12/08/2014] [Indexed: 12/03/2022]
Abstract
Over 20% of the world's tropical forests have been selectively logged, and large expanses are allocated for future timber extraction. Reduced‐impact logging (RIL) is being promoted as best practice forestry that increases sustainability and lowers CO2 emissions from logging, by reducing collateral damage associated with timber extraction. RIL is also expected to minimize the impacts of selective logging on biodiversity, although this is yet to be thoroughly tested. We undertake the most comprehensive study to date to investigate the biodiversity impacts of RIL across multiple taxonomic groups. We quantified birds, bats and large mammal assemblage structures, using a before‐after control‐impact (BACI) design across 20 sample sites over a 5‐year period. Faunal surveys utilized point counts, mist nets and line transects and yielded >250 species. We examined assemblage responses to logging, as well as partitions of feeding guild and strata (understorey vs. canopy), and then tested for relationships with logging intensity to assess the primary determinants of community composition. Community analysis revealed little effect of RIL on overall assemblages, as structure and composition were similar before and after logging, and between logging and control sites. Variation in bird assemblages was explained by natural rates of change over time, and not logging intensity. However, when partitioned by feeding guild and strata, the frugivorous and canopy bird ensembles changed as a result of RIL, although the latter was also associated with change over time. Bats exhibited variable changes post‐logging that were not related to logging, whereas large mammals showed no change at all. Indicator species analysis and correlations with logging intensities revealed that some species exhibited idiosyncratic responses to RIL, whilst abundance change of most others was associated with time. Synthesis and applications. Our study demonstrates the relatively benign effect of reduced‐impact logging (RIL) on birds, bats and large mammals in a neotropical forest context, and therefore, we propose that forest managers should improve timber extraction techniques more widely. If RIL is extensively adopted, forestry concessions could represent sizeable and important additions to the global conservation estate – over 4 million km2.
Our study demonstrates the relatively benign effect of reduced‐impact logging (RIL) on birds, bats and large mammals in a neotropical forest context, and therefore, we propose that forest managers should improve timber extraction techniques more widely. If RIL is extensively adopted, forestry concessions could represent sizeable and important additions to the global conservation estate – over 4 million km2.
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Affiliation(s)
- Jake E Bicknell
- Durrell Institute of Conservation and Ecology (DICE), School of Anthropology and Conservation, University of Kent Canterbury, CT2 7NR, UK ; Iwokrama International Centre for Rainforest Conservation and Development 77 High Street, Georgetown, Guyana
| | - Matthew J Struebig
- Durrell Institute of Conservation and Ecology (DICE), School of Anthropology and Conservation, University of Kent Canterbury, CT2 7NR, UK
| | - Zoe G Davies
- Durrell Institute of Conservation and Ecology (DICE), School of Anthropology and Conservation, University of Kent Canterbury, CT2 7NR, UK
| | - Christopher Baraloto
- Durrell Institute of Conservation and Ecology (DICE), School of Anthropology and Conservation, University of Kent Canterbury, CT2 7NR, UK
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Grogan J, Loveless MD. Flowering phenology and its implications for management of big-leaf mahogany Swietenia macrophylla in Brazilian Amazonia. Am J Bot 2013; 100:2293-2305. [PMID: 24214531 DOI: 10.3732/ajb.1300087] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
PREMISE OF THE STUDY Flowering phenology is a crucial determinant of reproductive success and offspring genetic diversity in plants. We measure the flowering phenology of big-leaf mahogany (Swietenia macrophylla, Meliaceae), a widely distributed neotropical tree, and explore how disturbance from logging impacts its reproductive biology. METHODS We use a crown scoring system to estimate the timing and duration of population-level flowering at three forest sites in the Brazilian Amazon over a five-year period. We combine this information with data on population structure and spatial distribution to consider the implications of logging for population flowering patterns and reproductive success. KEY RESULTS Mahogany trees as small as 14 cm diam flowered, but only trees > 30 cm diam flowered annually or supra-annually. Mean observed flowering periods by focal trees ranged from 18-34 d, and trees flowered sequentially during 3-4 mo beginning in the dry season. Focal trees demonstrated significant interannual correlation in flowering order. Estimated population-level flowering schedules resembled that of the focal trees, with temporal isolation between early and late flowering trees. At the principal study site, conventional logging practices eliminated 87% of mahogany trees > 30 cm diam and an estimated 94% of annual pre-logging floral effort. CONCLUSIONS Consistent interannual patterns of sequential flowering among trees create incompletely isolated subpopulations, constraining pollen flow. After harvests, surviving subcommercial trees will have fewer, more distant, and smaller potential partners, with probable consequences for post-logging regeneration. These results have important implications for the sustainability of harvesting systems for tropical timber species.
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Affiliation(s)
- James Grogan
- Mount Holyoke College, Department of Biology, South Hadley, Massachusetts 01075 USA
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