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Xie Y, Shen Z, Wang T, Malanson GP, Peñuelas J, Wang X, Chen X, Liang E, Liu H, Yang M, Ying L, Zhao F, Piao S. Uppermost global tree elevations are primarily limited by low temperature or insufficient moisture. GLOBAL CHANGE BIOLOGY 2024; 30:e17260. [PMID: 38563236 DOI: 10.1111/gcb.17260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2024] [Revised: 03/11/2024] [Accepted: 03/12/2024] [Indexed: 04/04/2024]
Abstract
The impact of anthropogenic global warming has induced significant upward dispersal of trees to higher elevations at alpine treelines. Assessing vertical deviation from current uppermost tree distributions to potential treeline positions is crucial for understanding ecosystem responses to evolving global climate. However, due to data resolution constraints and research scale limitation, comprehending the global pattern of alpine treeline elevations and driving factors remains challenging. This study constructed a comprehensive quasi-observational dataset of uppermost tree distribution across global mountains using Google Earth imagery. Validating the isotherm of mean growing-season air temperature at 6.6 ± 0.3°C as the global indicator of thermal treeline, we found that around two-thirds of uppermost tree distribution records significantly deviated from it. Drought conditions constitute the primary driver in 51% of cases, followed by mountain elevation effect which indicates surface heat (27%). Our analyses underscore the multifaceted determinants of global patterns of alpine treeline, explaining divergent treeline responses to climate warming. Moisture, along with temperature and disturbance, plays the most fundamental roles in understanding global variation of alpine treeline elevation and forecasting alpine treeline response to ongoing global warming.
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Affiliation(s)
- Yuyang Xie
- College of Urban and Environmental Sciences and MOE Laboratory for Earth Surface Processes, Peking University, Beijing, China
| | - Zehao Shen
- College of Urban and Environmental Sciences and MOE Laboratory for Earth Surface Processes, Peking University, Beijing, China
| | - Tao Wang
- State Key Laboratory of Tibetan Plateau Earth System, Environment and Resources (TPESER), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China
| | | | - Josep Peñuelas
- CREAF, Cerdanyola del Vallès, Barcelona, Catalonia, Spain
- CSIC, Global Ecology Unit CREAF-CSIC-UAB, Barcelona, Catalonia, Spain
| | - Xiaoyi Wang
- State Key Laboratory of Tibetan Plateau Earth System, Environment and Resources (TPESER), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China
| | - Xiangwu Chen
- College of Urban and Environmental Sciences and MOE Laboratory for Earth Surface Processes, Peking University, Beijing, China
| | - Eryuan Liang
- State Key Laboratory of Tibetan Plateau Earth System, Environment and Resources (TPESER), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China
| | - Hongyan Liu
- College of Urban and Environmental Sciences and MOE Laboratory for Earth Surface Processes, Peking University, Beijing, China
| | - Mingzheng Yang
- College of Urban and Environmental Sciences and MOE Laboratory for Earth Surface Processes, Peking University, Beijing, China
| | - Lingxiao Ying
- College of Urban and Environmental Sciences and MOE Laboratory for Earth Surface Processes, Peking University, Beijing, China
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China
| | - Fu Zhao
- College of Urban and Environmental Sciences and MOE Laboratory for Earth Surface Processes, Peking University, Beijing, China
| | - Shilong Piao
- College of Urban and Environmental Sciences and MOE Laboratory for Earth Surface Processes, Peking University, Beijing, China
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2
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Unterholzner L, Castagneri D, Cerrato R, Știrbu MI, Roibu CC, Carrer M. Climate response of a glacial relict conifer across its distribution range is invariant in space but not in time. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 906:167512. [PMID: 37813259 DOI: 10.1016/j.scitotenv.2023.167512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 09/22/2023] [Accepted: 09/29/2023] [Indexed: 10/11/2023]
Abstract
Climate change impacts on forest trees will be particularly severe for relict species endemic to the subalpine forest, such as Pinus cembra in the Alps and Carpathians. Most current knowledge about the response of this species to climate comes from tree-ring width analysis. However, this approach cannot perform in-depth and highly time-resolved analysis on the climate influence on specific growth processes and xylem functions. We analyzed xylem anatomical traits from six sites covering most of the longitudinal range of this species. Associations between climate and cell number, lumen area and cell wall thickness were computed for the 1920-2010 period using climate records aligned to degree-day temperature sum thresholds. The anatomical chronologies were clearly distinct between the Alps and Carpathians. However, climate responses were similar for all sites, suggesting common species-specific response mechanisms. Temperature showed a positive correlation with both cell number and cell wall thickness. Cell lumen size exhibited an early positive association, followed by strong negative association with temperature and a positive one with precipitation. This highlights that the cell enlargement process was negatively related to high temperature at high elevation, where meristematic processes are rather supposed to be constrained by low temperatures. Therefore, long-term climate warming can have negative consequences on the xylem potential to transport water at all investigated sites. Moreover, in the last 30 years, we observed a slight anticipation of some responses and a decrease in climate sensitivity of some xylem parameters. Our findings provide evidence of temporally unstable but spatially consistent climate response of Pinus cembra from the Alps to the Carpathians. The low diversity in xylem phenotypic responses to climate suggests that future warming could extensively and evenly affect the species throughout its entire distribution.
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Affiliation(s)
- Lucrezia Unterholzner
- Department of Land, Environment, Agriculture and Forestry (TESAF), University of Padova, via dell'Università 16, 35020 Legnaro, Italy; Chair of Forest Growth and Woody Biomass Production, Technische Universität Dresden, Pienner Straße 8, 01737 Tharandt, Germany
| | - Daniele Castagneri
- Department of Land, Environment, Agriculture and Forestry (TESAF), University of Padova, via dell'Università 16, 35020 Legnaro, Italy.
| | - Riccardo Cerrato
- Department of Earth Sciences (DST), University of Pisa, via S. Maria 53, 56124 Pisa, Italy
| | - Marian-Ionuț Știrbu
- Forest Biometrics Laboratory, Faculty of Forestry, "Ștefan cel Mare" University of Suceava, Universității street, no. 13, 720229 Suceava, Romania
| | - Cătălin-Constantin Roibu
- Forest Biometrics Laboratory, Faculty of Forestry, "Ștefan cel Mare" University of Suceava, Universității street, no. 13, 720229 Suceava, Romania
| | - Marco Carrer
- Department of Land, Environment, Agriculture and Forestry (TESAF), University of Padova, via dell'Università 16, 35020 Legnaro, Italy
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3
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Ainsworth A, Drake DR. Hawaiian Treeline Ecotones: Implications for Plant Community Conservation under Climate Change. PLANTS (BASEL, SWITZERLAND) 2023; 13:123. [PMID: 38202431 PMCID: PMC10780311 DOI: 10.3390/plants13010123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 12/15/2023] [Accepted: 12/24/2023] [Indexed: 01/12/2024]
Abstract
Species within tropical alpine treeline ecotones are predicted to be especially sensitive to climate variability because this zone represents tree species' altitudinal limits. Hawaiian volcanoes have distinct treeline ecotones driven by trade wind inversions. The local climate is changing, but little is known about how this influences treeline vegetation. To predict future impacts of climate variability on treelines, we must define the range of variation in treeline ecotone characteristics. Previous studies highlighted an abrupt transition between subalpine grasslands and wet forest on windward Haleakalā, but this site does not represent the diversity of treeline ecotones among volcanoes, lava substrates, and local climatic conditions. To capture this diversity, we used data from 225 plots spanning treelines (1500-2500 m) on Haleakalā and Mauna Loa to characterize ecotonal plant communities. Treeline indicator species differ by moisture and temperature, with common native species important for wet forest, subalpine woodland, and subalpine shrubland. The frequency or abundance of community indicator species may be better predictors of shifting local climates than the presence or absence of tree life forms per se. This study further supports the hypothesis that changes in available moisture, rather than temperature, will dictate the future trajectory of Hawaiian treeline ecotone communities.
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Affiliation(s)
- Alison Ainsworth
- School of Life Sciences, University of Hawai’i at Mānoa, Honolulu, HI 96822, USA;
- National Park Service, Pacific Island Inventory and Monitoring Network, Hawaii National Park, HI 96718, USA
| | - Donald R. Drake
- School of Life Sciences, University of Hawai’i at Mānoa, Honolulu, HI 96822, USA;
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4
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Tumajer J, Altman J, Lehejček J. Linkage between growth phenology and climate-growth responses along landscape gradients in boreal forests. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 905:167153. [PMID: 37730045 DOI: 10.1016/j.scitotenv.2023.167153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 09/14/2023] [Accepted: 09/15/2023] [Indexed: 09/22/2023]
Abstract
Boreal forests represent an important carbon sink and, therefore, significantly contribute to climate change mitigation. Tree-ring width series of boreal species reflect climate variation at the moment of tree-ring formation but also lagged climatic effects from dormancy preceding tree-ring formation and antecedent growing seasons. However, little is known about how the growth sensitivity to climate in specific intra-annual periods varies across the landscape. Here, we assessed growth responses to climate variation during the 45 months preceding the tree-ring formation for nine boreal stands of Picea glauca and Picea mariana distributed along the gradients of elevation and slope aspect. We combined process-based modeling of wood formation and remote sensing data to determine growth phenology at each site. Next, we classified intra-annual seasons with significant climate-growth correlations based on the timing of dormancy and growth periods. Both the phenology and the climate-growth relationships systematically shifted with elevation and, to a lower extent, also with slope orientation at the treeline. The mean duration of the growing season varied between 100 days at treelines above 900 m and 160 days at lowlands below 500 m. The growth at treelines was stimulated by temperature in the summer of the tree-ring formation year and two years before tree-ring formation. The period of significant climate-growth correlations during the current summer did not exceed three months in agreement with the local duration of the growing season. The growth of trees in lower elevations was instead stimulated by high temperature during the dormancy periods but restricted by high temperature in antecedent summer seasons. In conclusion, our study highlights the linkage between the timing of climate-growth sensitivity and growth phenology, primarily determined by proximity to the treeline. Consequently, accounting for landscape gradients in growth phenology is crucial for upscaling the climatic limits of boreal stands' growth as climate change progresses.
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Affiliation(s)
- Jan Tumajer
- Department of Physical Geography and Geoecology, Faculty of Science, Charles University, Albertov 6, 12843 Prague, Czech Republic.
| | - Jan Altman
- Institute of Botany, The Czech Academy of Sciences, Dukelská 135, 37901 Třeboň, Czech Republic; Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, Kamýcká 129, 165 21 Prague 6, Suchdol, Czech Republic
| | - Jiří Lehejček
- Department of Environment, Faculty of Environment, Jan Evangelista Purkyně University, Pasteurova 15, 400 96 Ústí nad Labem, Czech Republic; Department of Environmental Security, Faculty of Logistics and Crisis Management, Tomas Bata University in Zlin, Studentské nám. 1532, 686 01 Uherské Hradiště, Czech Republic
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5
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Qiu J, Feng S, Yuan W. Upward-moving mountain treelines: An indicator of changing climate. GLOBAL CHANGE BIOLOGY 2023; 29:6832-6833. [PMID: 37772665 DOI: 10.1111/gcb.16954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2023] [Revised: 09/08/2023] [Accepted: 09/14/2023] [Indexed: 09/30/2023]
Abstract
In this commentary, we highlight the recent advancements in the field of mountain treeline response to climate change in the work by He et al. (2023). We summarize their work from the perspectives of mountain treeline spatial distribution, their bioclimatic controls, and their diverse responses to changes in global climate patterns. We expect wide implications from the work of He et al. (2023), and point out future research direction that calls for interdisciplinary attention.
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Affiliation(s)
- Jianxiu Qiu
- Guangdong Provincial Key Laboratory of Urbanization and Geo-simulation, School of Geography and Planning, Sun Yat-sen University, Guangzhou, China
| | - Sijia Feng
- Guangdong Provincial Key Laboratory of Urbanization and Geo-simulation, School of Geography and Planning, Sun Yat-sen University, Guangzhou, China
| | - Wenping Yuan
- School of Atmospheric Sciences, Sun Yat-sen University, Zhuhai, China
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6
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He X, Jiang X, Spracklen DV, Holden J, Liang E, Liu H, Xu C, Du J, Zhu K, Elsen PR, Zeng Z. Global distribution and climatic controls of natural mountain treelines. GLOBAL CHANGE BIOLOGY 2023; 29:7001-7011. [PMID: 37477066 DOI: 10.1111/gcb.16885] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 05/30/2023] [Accepted: 06/16/2023] [Indexed: 07/22/2023]
Abstract
Mountain treelines are thought to be sensitive to climate change. However, how climate impacts mountain treelines is not yet fully understood as treelines may also be affected by other human activities. Here, we focus on "closed-loop" mountain treelines (CLMT) that completely encircle a mountain and are less likely to have been influenced by human land-use change. We detect a total length of ~916,425 km of CLMT across 243 mountain ranges globally and reveal a bimodal latitudinal distribution of treeline elevations with higher treeline elevations occurring at greater distances from the coast. Spatially, we find that temperature is the main climatic driver of treeline elevation in boreal and tropical regions, whereas precipitation drives CLMT position in temperate zones. Temporally, we show that 70% of CLMT have moved upward, with a mean shift rate of 1.2 m/year over the first decade of the 21st century. CLMT are shifting fastest in the tropics (mean of 3.1 m/year), but with greater variability. Our work provides a new mountain treeline database that isolates climate impacts from other anthropogenic pressures, and has important implications for biodiversity, natural resources, and ecosystem adaptation in a changing climate.
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Affiliation(s)
- Xinyue He
- School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen, China
- School of Earth and Environment, University of Leeds, Leeds, UK
| | - Xin Jiang
- School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen, China
| | | | | | - Eryuan Liang
- Key Laboratory of Alpine Ecology, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China
- CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing, China
| | - Hongyan Liu
- College of Urban and Environmental Science and MOE Laboratory for Earth Surface Processes, Peking University, Beijing, China
| | - Chongyang Xu
- College of Urban and Environmental Science and MOE Laboratory for Earth Surface Processes, Peking University, Beijing, China
| | - Jianhui Du
- School of Geography and Planning, Sun Yat-Sen University, Guangzhou, China
| | - Kai Zhu
- Department of Environmental Studies, University of California, Santa Cruz, California, USA
- Institute for Global Change Biology and School for Environment and Sustainability, University of Michigan, Ann Arbor, Michigan, USA
| | - Paul R Elsen
- Wildlife Conservation Society, Global Conservation Program, Bronx, New York, USA
| | - Zhenzhong Zeng
- School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen, China
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7
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Fang S, He Z, Zhao M. Fifty years of change in the lower tree line in an arid coniferous forest in the Qilian Mountains, northwestern China. PLoS One 2023; 18:e0292682. [PMID: 37824484 PMCID: PMC10569624 DOI: 10.1371/journal.pone.0292682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Accepted: 09/26/2023] [Indexed: 10/14/2023] Open
Abstract
Tree line areas exhibited significant changes in response to climate change, including upward migration. Lower tree line dynamics are rarely studied, but as unique features in arid and semi-arid areas, they may influence forest distribution. Here, eight lower tree line plots in a Picea crassifolia Kom. (Qinghai spruce) forest in the arid and semi-arid Qilian Mountains of northwestern China were used to determine changes in tree line location and relationships with meteorological factors during 1968-2018. The results showed that the lower tree line descended by an average of 9.82 m during 1968 to 2018, and exhibited almost no change after 2008. The change in the lower tree line was significantly correlated with the annual average temperature (°C) and annual precipitation (mm) and may be affected by human activities. In the past 50 years, the lower tree line in arid areas exhibited a downward trend. Our findings indicate that the movement of the lower tree line is also an important aspect of climatic changes in coniferous forest distribution in arid and semi-arid mountains.
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Affiliation(s)
- Shu Fang
- College of Urban, Rural Planning and Architectural Engineering, Shangluo University, Shangluo, Shanxi, China
| | - Zhibin He
- Linze Inland River Basin Research Station, Chinese Ecosystem Research Network, Key Laboratory of Eco-hydrology of Inland River Basin, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, Gansu, China
| | - Minmin Zhao
- Key Laboratory of Hydrogeology, Center for Hydrogeology and Environmental Geology Survey, China Geological Survey, Baoding, Hebei, China
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8
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Li X, Liang E, Camarero JJ, Rossi S, Zhang J, Zhu H, Fu YH, Sun J, Wang T, Piao S, Peñuelas J. Warming-induced phenological mismatch between trees and shrubs explains high-elevation forest expansion. Natl Sci Rev 2023; 10:nwad182. [PMID: 37671321 PMCID: PMC10476895 DOI: 10.1093/nsr/nwad182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2023] [Revised: 06/21/2023] [Accepted: 06/24/2023] [Indexed: 09/07/2023] Open
Abstract
Despite the importance of species interaction in modulating the range shifts of plants, little is known about the responses of coexisting life forms to a warmer climate. Here, we combine long-term monitoring of cambial phenology in sympatric trees and shrubs at two treelines of the Tibetan Plateau, with a meta-analysis of ring-width series from 344 shrubs and 575 trees paired across 11 alpine treelines in the Northern Hemisphere. Under a spring warming of +1°C, xylem resumption advances by 2-4 days in trees, but delays by 3-8 days in shrubs. The divergent phenological response to warming was due to shrubs being 3.2 times more sensitive than trees to chilling accumulation. Warmer winters increased the thermal requirement for cambial reactivation in shrubs, leading to a delayed response to warmer springs. Our meta-analysis confirmed such a mechanism across continental scales. The warming-induced phenological mismatch may give a competitive advantage to trees over shrubs, which would provide a new explanation for increasing alpine treeline shifts under the context of climate change.
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Affiliation(s)
- Xiaoxia Li
- State Key Laboratory of Tibetan Plateau Earth System, Environment and Resources (TPESER), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China
- Laboratoire sur les écosystèmes terrestres boréaux, Département des Sciences Fondamentales, Université du Québec à Chicoutimi, Chicoutimi G7H2B1, Canada
| | - Eryuan Liang
- State Key Laboratory of Tibetan Plateau Earth System, Environment and Resources (TPESER), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China
| | - J Julio Camarero
- InstitutoPirenaico de Ecología (IPE-CSIC), Zaragoza 50059, Spain
| | - Sergio Rossi
- Laboratoire sur les écosystèmes terrestres boréaux, Département des Sciences Fondamentales, Université du Québec à Chicoutimi, Chicoutimi G7H2B1, Canada
| | - Jingtian Zhang
- State Key Laboratory of Tibetan Plateau Earth System, Environment and Resources (TPESER), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Haifeng Zhu
- State Key Laboratory of Tibetan Plateau Earth System, Environment and Resources (TPESER), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Yongshuo H Fu
- College of Water Sciences, Beijing Normal University, Beijing 100875, China
| | - Jian Sun
- State Key Laboratory of Tibetan Plateau Earth System, Environment and Resources (TPESER), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Tao Wang
- State Key Laboratory of Tibetan Plateau Earth System, Environment and Resources (TPESER), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Shilong Piao
- State Key Laboratory of Tibetan Plateau Earth System, Environment and Resources (TPESER), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Josep Peñuelas
- CREAF, Cerdanyola del Valles, Barcelona 08193, Spain
- CSIC, Global Ecology Unit CREAF-CSIC-UAB, Bellaterra, Barcelona 08193, Spain
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9
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Mata-Guel EO, Soh MCK, Butler CW, Morris RJ, Razgour O, Peh KSH. Impacts of anthropogenic climate change on tropical montane forests: an appraisal of the evidence. Biol Rev Camb Philos Soc 2023; 98:1200-1224. [PMID: 36990691 DOI: 10.1111/brv.12950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 03/08/2023] [Accepted: 03/10/2023] [Indexed: 03/31/2023]
Abstract
In spite of their small global area and restricted distributions, tropical montane forests (TMFs) are biodiversity hotspots and important ecosystem services providers, but are also highly vulnerable to climate change. To protect and preserve these ecosystems better, it is crucial to inform the design and implementation of conservation policies with the best available scientific evidence, and to identify knowledge gaps and future research needs. We conducted a systematic review and an appraisal of evidence quality to assess the impacts of climate change on TMFs. We identified several skews and shortcomings. Experimental study designs with controls and long-term (≥10 years) data sets provide the most reliable evidence, but were rare and gave an incomplete understanding of climate change impacts on TMFs. Most studies were based on predictive modelling approaches, short-term (<10 years) and cross-sectional study designs. Although these methods provide moderate to circumstantial evidence, they can advance our understanding on climate change effects. Current evidence suggests that increasing temperatures and rising cloud levels have caused distributional shifts (mainly upslope) of montane biota, leading to alterations in biodiversity and ecological functions. Neotropical TMFs were the best studied, thus the knowledge derived there can serve as a proxy for climate change responses in under-studied regions elsewhere. Most studies focused on vascular plants, birds, amphibians and insects, with other taxonomic groups poorly represented. Most ecological studies were conducted at species or community levels, with a marked paucity of genetic studies, limiting understanding of the adaptive capacity of TMF biota. We thus highlight the long-term need to widen the methodological, thematic and geographical scope of studies on TMFs under climate change to address these uncertainties. In the short term, however, in-depth research in well-studied regions and advances in computer modelling approaches offer the most reliable sources of information for expeditious conservation action for these threatened forests.
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Affiliation(s)
- Erik O Mata-Guel
- School of Biological Sciences, University of Southampton, Highfield Campus, Southampton, SO17 1BJ, UK
| | - Malcolm C K Soh
- National Park Boards, 1 Cluny Road, Singapore, 259569, Singapore
| | - Connor W Butler
- School of Biological Sciences, University of Southampton, Highfield Campus, Southampton, SO17 1BJ, UK
| | - Rebecca J Morris
- School of Biological Sciences, University of Southampton, Highfield Campus, Southampton, SO17 1BJ, UK
| | - Orly Razgour
- Biosciences, University of Exeter, Exeter, EX4 4PS, UK
| | - Kelvin S-H Peh
- School of Biological Sciences, University of Southampton, Highfield Campus, Southampton, SO17 1BJ, UK
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10
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Rita A, Saracino A, Cieraad E, Saulino L, Zotti M, Idbella M, De Stefano C, Mogavero V, Allevato E, Bonanomi G. Topoclimate effect on treeline elevation depends on the regional framework: A contrast between Southern Alps (New Zealand) and Apennines (Italy) forests. Ecol Evol 2023; 13:e9733. [PMID: 36694545 PMCID: PMC9843241 DOI: 10.1002/ece3.9733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Revised: 12/15/2022] [Accepted: 12/23/2022] [Indexed: 01/18/2023] Open
Abstract
Deciphering the spatial patterns of alpine treelines is critical for understanding the ecosystem processes involved in the persistence of tree species and their altitudinal limit. Treelines are thought to be controlled by temperature, and other environmental variables but they have rarely been investigated in regions with different land-use change legacies. Here, we systematically investigated treeline elevation in the Apennines (Italy) and Southern Alps (New Zealand) with contrasting human history but similar biogeographic trajectories, intending to identify distinct drivers that affect their current elevation and highlight their respective peculiarities. Over 3622 km of Apennines, treeline elevation was assessed in 302 mountain peaks and in 294 peaks along 4504 km of Southern Alps. The major difference between the Southern Alps and Apennines treeline limit is associated with their mountain aspects. In the Southern Alps, the scarcely anthropized Nothofagus treeline elevation was higher on the warmer equator-facing slopes than on the pole-facing ones. Contrary to what would be expected based on temperature limitation, the elevation of Fagus sylvatica treelines in the Apennines was higher on colder, pole-facing slopes than on human-shaped equator-facing, warmer mountainsides. Pervasive positive correlations were found between treeline elevation and temperature in the Southern Alps but not in the Apennines. While the position of the Fagus and Nothofagus treelines converge on similar isotherms of annual average temperature, a striking isothermal difference between the temperatures of the hottest month on which the two taxonomic groups grow exists. We conclude that actual treeline elevation reflects the ecological processes driven by a combination of local-scale topoclimatic conditions, and human disturbance legacy. Predicting dynamic processes affecting current and future alpine treeline position requires further insight into the modulating influences that are currently understood at a regional scale.
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Affiliation(s)
- Angelo Rita
- Dipartimento di AgrariaUniversità degli Studi di Napoli Federico IIPorticiItaly
| | - Antonio Saracino
- Dipartimento di AgrariaUniversità degli Studi di Napoli Federico IIPorticiItaly
| | - Ellen Cieraad
- Research & Innovation CentreNelson Marlborough Institute of TechnologyNelsonNew Zealand
| | - Luigi Saulino
- Dipartimento di AgrariaUniversità degli Studi di Napoli Federico IIPorticiItaly
| | - Maurizio Zotti
- Dipartimento di AgrariaUniversità degli Studi di Napoli Federico IIPorticiItaly
| | - Mohamed Idbella
- Dipartimento di AgrariaUniversità degli Studi di Napoli Federico IIPorticiItaly,Laboratory of Biosciences, Faculty of Sciences and TechniquesHassan II UniversityCasablancaMorocco
| | - Carlo De Stefano
- Dipartimento di AgrariaUniversità degli Studi di Napoli Federico IIPorticiItaly
| | - Valentina Mogavero
- Dipartimento di AgrariaUniversità degli Studi di Napoli Federico IIPorticiItaly
| | - Emilia Allevato
- Dipartimento di AgrariaUniversità degli Studi di Napoli Federico IIPorticiItaly
| | - Giuliano Bonanomi
- Dipartimento di AgrariaUniversità degli Studi di Napoli Federico IIPorticiItaly,Task Force on Microbiome StudiesUniversità degli Studi di Napoli Federico IINaplesItaly
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11
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Tumajer J, Begović K, Čada V, Jenicek M, Lange J, Mašek J, Kaczka RJ, Rydval M, Svoboda M, Vlček L, Treml V. Ecological and methodological drivers of non-stationarity in tree growth response to climate. GLOBAL CHANGE BIOLOGY 2023; 29:462-476. [PMID: 36200330 DOI: 10.1111/gcb.16470] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Accepted: 09/07/2022] [Indexed: 06/16/2023]
Abstract
Radial tree growth is sensitive to environmental conditions, making observed growth increments an important indicator of climate change effects on forest growth. However, unprecedented climate variability could lead to non-stationarity, that is, a decoupling of tree growth responses from climate over time, potentially inducing biases in climate reconstructions and forest growth projections. Little is known about whether and to what extent environmental conditions, species, and model type and resolution affect the occurrence and magnitude of non-stationarity. To systematically assess potential drivers of non-stationarity, we compiled tree-ring width chronologies of two conifer species, Picea abies and Pinus sylvestris, distributed across cold, dry, and mixed climates. We analyzed 147 sites across the Europe including the distribution margins of these species as well as moderate sites. We calibrated four numerical models (linear vs. non-linear, daily vs. monthly resolution) to simulate growth chronologies based on temperature and soil moisture data. Climate-growth models were tested in independent verification periods to quantify their non-stationarity, which was assessed based on bootstrapped transfer function stability tests. The degree of non-stationarity varied between species, site climatic conditions, and models. Chronologies of P. sylvestris showed stronger non-stationarity compared with Picea abies stands with a high degree of stationarity. Sites with mixed climatic signals were most affected by non-stationarity compared with sites sampled at cold and dry species distribution margins. Moreover, linear models with daily resolution exhibited greater non-stationarity compared with monthly-resolved non-linear models. We conclude that non-stationarity in climate-growth responses is a multifactorial phenomenon driven by the interaction of site climatic conditions, tree species, and methodological features of the modeling approach. Given the existence of multiple drivers and the frequent occurrence of non-stationarity, we recommend that temporal non-stationarity rather than stationarity should be considered as the baseline model of climate-growth response for temperate forests.
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Affiliation(s)
- Jan Tumajer
- Department of Physical Geography and Geoecology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Krešimir Begović
- Faculty of Forestry and Wood Science, Department of Forest Ecology, Czech University of Life Science, Prague, Czech Republic
| | - Vojtěch Čada
- Faculty of Forestry and Wood Science, Department of Forest Ecology, Czech University of Life Science, Prague, Czech Republic
| | - Michal Jenicek
- Department of Physical Geography and Geoecology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Jelena Lange
- Department of Physical Geography and Geoecology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Jiří Mašek
- Department of Physical Geography and Geoecology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Ryszard J Kaczka
- Department of Physical Geography and Geoecology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Miloš Rydval
- Faculty of Forestry and Wood Science, Department of Forest Ecology, Czech University of Life Science, Prague, Czech Republic
| | - Miroslav Svoboda
- Faculty of Forestry and Wood Science, Department of Forest Ecology, Czech University of Life Science, Prague, Czech Republic
| | - Lukáš Vlček
- Department of Physical Geography and Geoecology, Faculty of Science, Charles University, Prague, Czech Republic
- Institute of Hydrodynamics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Václav Treml
- Department of Physical Geography and Geoecology, Faculty of Science, Charles University, Prague, Czech Republic
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12
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Wu F, Jiang Y, Zhao S, Wen Y, Li W, Kang M. Applying space-for-time substitution to infer the growth response to climate may lead to overestimation of tree maladaptation: Evidence from the North American White Spruce Network. GLOBAL CHANGE BIOLOGY 2022; 28:5172-5184. [PMID: 35714046 DOI: 10.1111/gcb.16304] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Revised: 05/21/2022] [Accepted: 06/02/2022] [Indexed: 06/15/2023]
Abstract
Under climate change circumstances, increasing studies have reported the temporal instability of tree growth responses to climate, which poses a major challenge to linearly extrapolating past climate and future growth dynamics using tree-ring data. Space-for-time substitution (SFTS) is a potential solution to this problem that is widely used in the dendrochronology field to project past or future temporal growth response trajectories from contemporary spatial patterns. However, the projected accuracy of the SFTS in the climate effects on tree growth remains uncertain. Here, we empirically test the SFTS method by comparing the effect of spatial and temporal climate variations on climate responses of white spruce (Picea glauca), which has a transcontinental range in North America. We first applied a response surface regression model to capture the variations in growth responses along the spatial climate gradients. The results showed that the relationships between growth and June temperature varied along spatial climate gradients in a predictable way. And their relationships varied mainly along with local temperate condition. Then, the projected correlation coefficients between growth and climate using SFTS were compared against the observed. We found that the growth response changes caused by spatial versus temporal climate variations showed opposite trends. Moreover, the projected correlation coefficients using the SFTS were significantly lower than the observed. This finding suggests that applying the SFTS to project the growth response of white spruce might lead to an overestimation of the degree of tree maladaptation in future climate scenarios. And the overestimation is likely to get weaker from Alaska and Yukon Territory in the west to Quebec in the east. Although this is only a case study of the SFTS method for projecting tree growth response, our findings suggest that direct application of the SFTS method may not be applicable to all regions and all tree species.
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Affiliation(s)
- Fang Wu
- State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Zhuhai, China
- Beijing Key Laboratory of Traditional Chinese Medicine Protection and Utilization, Faculty of Geographical Science, Beijing Normal University, Beijing, China
| | - Yuan Jiang
- State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Zhuhai, China
- Beijing Key Laboratory of Traditional Chinese Medicine Protection and Utilization, Faculty of Geographical Science, Beijing Normal University, Beijing, China
| | - Shoudong Zhao
- State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing, China
| | - Yan Wen
- State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Zhuhai, China
- Beijing Key Laboratory of Traditional Chinese Medicine Protection and Utilization, Faculty of Geographical Science, Beijing Normal University, Beijing, China
| | - Wenqing Li
- Ministry of Natural Resources of the People's Republic of China, Key Laboratory of Land Consolidation and Rehabilitation, Land Consolidation and Rehabilitation Center, Beijing, China
| | - Muyi Kang
- Beijing Key Laboratory of Traditional Chinese Medicine Protection and Utilization, Faculty of Geographical Science, Beijing Normal University, Beijing, China
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13
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Știrbu MI, Roibu CC, Carrer M, Mursa A, Unterholzner L, Prendin AL. Contrasting Climate Sensitivity of Pinus cembra Tree-Ring Traits in the Carpathians. FRONTIERS IN PLANT SCIENCE 2022; 13:855003. [PMID: 35755705 PMCID: PMC9228034 DOI: 10.3389/fpls.2022.855003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 04/22/2022] [Indexed: 06/15/2023]
Abstract
High-elevation ecosystems are one of the most sensitive to climate change. The analysis of growth and xylem structure of trees from marginal populations, especially the ones growing at the treeline, could provide early-warning signs to better understand species-specific responses to future climate conditions. In this study, we combined classical dendrochronology with wood density and anatomical measurements to investigate the climate sensitivity of Pinus cembra L., a typical European high-elevation tree species distributed in isolated patches in the Carpathians. Samples were collected from the Retezat Mountains, South-Western Romania. We analyzed ring width (TRW), maximum density (MXD), xylem anatomical traits [cell number per ring (CNo), cell density (CD), conduit area (CA), and cell wall thickness (CWT)] time series, split into ring sectors and assessed the relationships with monthly and daily climate records over the last century (1901-2015). The analysis showed a strong dependency of TRW on CNo and MXD on CWT. Summer temperature positively correlated with MXD and CWT [monthly correlation (r) were 0.65 and 0.48 respectively] from the early to late wood but not TRW (r = 0.22). CA positively correlated with water availability (r = 0.37) and negatively correlated with temperature (r = -0.39). This study improves our general understanding of the climate-growth relationships of a European high-elevation tree species and the results could be considered for forecasting population dynamics on projected changes in climate.
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Affiliation(s)
- Marian-Ionuț Știrbu
- Forest Biometrics Laboratory, Faculty of Forestry, ‘Stefan cel Mare’ University of Suceava, Suceava, Romania
| | - Cătălin-Constantin Roibu
- Forest Biometrics Laboratory, Faculty of Forestry, ‘Stefan cel Mare’ University of Suceava, Suceava, Romania
| | - Marco Carrer
- Department of Land Environment Agriculture and Forestry, University of Padova, Legnaro, Italy
| | - Andrei Mursa
- Forest Biometrics Laboratory, Faculty of Forestry, ‘Stefan cel Mare’ University of Suceava, Suceava, Romania
| | - Lucrezia Unterholzner
- Department of Land Environment Agriculture and Forestry, University of Padova, Legnaro, Italy
| | - Angela Luisa Prendin
- Department of Land Environment Agriculture and Forestry, University of Padova, Legnaro, Italy
- Department of Biology, Aarhus University, Aarhus, Denmark
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14
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Yang J, Zhang Q, Song W, Zhang X, Wang X. Radial Growth of Trees Rather Than Shrubs in Boreal Forests Is Inhibited by Drought. FRONTIERS IN PLANT SCIENCE 2022; 13:912916. [PMID: 35720605 PMCID: PMC9201406 DOI: 10.3389/fpls.2022.912916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Accepted: 05/09/2022] [Indexed: 06/15/2023]
Abstract
Of all forest biomes, boreal forests are experiencing the most significant warming. Drought caused by warming has a dramatic impact on species in boreal forests. However, little is known about whether the growth of trees and shrubs in boreal forests responds consistently to warming and drought. We obtained the tree-ring width data of 308 trees (Larix gmelinii and Pinus sylvestris var. mongolica) and 133 shrubs (Pinus pumila) from 26 sites in northeastern China. According to the climate data from 1950 to 2014, we determined three extreme drought years (1954, 1967, and 2008). The response difference of radial growth of trees and shrubs in boreal forests to drought was compared using resilience index, moving correlation and response analysis. The results showed that high temperature (mean and maximum temperature) in previous and current growing seasons promoted the growth of P. pumila, but inhibited the growth of trees. On the contrary, wetter conditions (higher PDSI) promoted tree growth but were not conducive to P. pumila growth in high latitudes. Moving correlation analysis showed similar results. In addition, water deficit was more likely to inhibit P. pumila growth in low latitudes. The drought resistance of P. pumila was stronger than that of L. gmelinii and P. sylvestris var. mongolica. Therefore, the growth loss and recovery time of P. pumila during drought was less than those of trees. We concluded that L. gmelinii and P. sylvestris var. mongolica are more prone to growth decline than P. pumila after the drought caused by climate warming. In the future climate warming, shrub growth may benefit more than trees. Our findings are of great significance in predicting the future changes in ecosystem composition and species distribution dynamics in extreme climate susceptible areas.
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Affiliation(s)
- Jingwen Yang
- School of Life, Qufu Normal University, Qufu, China
- College of Forestry, Inner Mongolia Agricultural University, Hohhot, China
- Center for Ecological Research and Key Laboratory of Sustainable Forest Ecosystem Management–Ministry of Education, College of Forestry, Northeast Forestry University, Harbin, China
| | - Qiuliang Zhang
- College of Forestry, Inner Mongolia Agricultural University, Hohhot, China
| | - Wenqi Song
- Center for Ecological Research and Key Laboratory of Sustainable Forest Ecosystem Management–Ministry of Education, College of Forestry, Northeast Forestry University, Harbin, China
| | - Xu Zhang
- College of Forestry, Northwest A&F University, Yangling, China
| | - Xiaochun Wang
- School of Life, Qufu Normal University, Qufu, China
- Center for Ecological Research and Key Laboratory of Sustainable Forest Ecosystem Management–Ministry of Education, College of Forestry, Northeast Forestry University, Harbin, China
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15
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Serra-Maluquer X, Gazol A, Anderegg WRL, Martínez-Vilalta J, Mencuccini M, Camarero JJ. Wood density and hydraulic traits influence species' growth response to drought across biomes. GLOBAL CHANGE BIOLOGY 2022; 28:3871-3882. [PMID: 35124877 DOI: 10.1111/gcb.16123] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 12/17/2021] [Accepted: 01/16/2022] [Indexed: 06/14/2023]
Abstract
Tree species display a wide variety of water-use strategies, growth rates and capacity to tolerate drought. However, if we want to forecast species capacity to cope with increasing aridity and drought, we need to identify which measurable traits confer resilience to drought across species. Here, we use a global tree ring network (65 species; 1931 site series of ring-width indices-RWI) to evaluate the relationship of long-term growth-drought sensitivity (RWI-SPEI drought index relationship) and short-term growth response to extreme drought episodes (resistance, recovery and resilience indices) with functional traits related to leaf, wood and hydraulic properties. Furthermore, we assess the influence of climate (temperature, precipitation and climatic water deficit) on these trait-growth relationships. We found a close correspondence between the long-term relationship between RWI and SPEI and resistance and recovery of tree growth to severe drought episodes. Species displaying a stronger RWI-SPEI relationship to drought and low resistance and high recovery to extreme drought episodes tended to have a higher wood density (WD) and more negative leaf minimum water potential (Ψmin). Such associations were largely maintained when accounting for direct climate effects. Our results indicate that, at a cross-species level and global scale, wood and hydraulic functional traits explain species' growth responses to drought at short- and long-term scales. These trait-growth response relationships can improve our understanding of the cross-species capacity to withstand climate change and inform models to better predict drought effects on forest ecosystem dynamics.
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Affiliation(s)
| | - Antonio Gazol
- Instituto Pirenaico de Ecología (IPE-CSIC), Zaragoza, Spain
| | | | - Jordi Martínez-Vilalta
- CREAF, Bellaterra (Cerdanyola del Vallés), Catalonia, Spain
- Universitat Autònoma de Barcelona, Bellaterra (Cerdanyola del Vallès), Catalonia, Spain
| | - Maurizio Mencuccini
- CREAF, Bellaterra (Cerdanyola del Vallés), Catalonia, Spain
- ICREA, Barcelona, Spain
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16
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Treeline-Quo Vadis? An Ecophysiological Approach. FORESTS 2022. [DOI: 10.3390/f13060857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
At high elevation or latitude, the margin of the life-form tree is set by low temperature, with trees defined as upright woody species taller than 2–3 m. Globally, the temperature limit of the life-form tree occurs whenever the growing season mean soil temperature declines to 6.7 ± 0.8 °C. Disturbance and human land use, however, can cause trees to be absent from the climatic treeline. After addressing definitions and concepts related to treeline ecophysiology and examining treeline structure and dynamics, the focus will be on future treeline developments with respect to climate, competition and land use change. Finally, changes in economic structure and land use within the treeline ecotone are outlined with respect to net ecosystem production and year-round evapotranspiration.
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17
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Heterogeneous Responses of Alpine Treelines to Climate Warming across the Tibetan Plateau. FORESTS 2022. [DOI: 10.3390/f13050788] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
The Tibetan Plateau hosts a continuous distribution of alpine treelines from the Qilian Mountains to the Hengduan Mountains and the Himalaya Mountains. However, not much is known about the broadscale alpine treeline dynamics and their responses to climate warming across the Tibetan Plateau. Herein, we collected a total of 59 treeline sites across different forest regions of the Tibetan Plateau and the related field data (i.e., upward advance magnitude, tree recruitment and height growth), expansion potential (i.e., elevational difference between the current treeline and the tree species line (EP)) and vegetation TI (an index of species interactions) from the published references. Site characteristics (e.g., elevation, slope and aspect) and the related environmental factors were used to analyze the relationships between treeline shifts and environmental variables. Despite increases in the recruitment and growth of trees at most treeline sites, alpine treeline positions showed heterogeneous responses to climate warming. Most treelines advanced over the last century, while some treelines showed long-term stability. EP was significantly and positively linked to the summer warming rate and treeline shifts, suggesting that the position of current tree species line is of crucial importance in evaluating treeline dynamics under climate change. In addition, warming-induced treeline advances were modulated by plant–plant interactions. Overall, this study highlighted the heterogeneous responses of regional-scale alpine treelines to climate warming on the Tibetan Plateau.
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18
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Gulzar A, Hamid M, Dar FA, Wani SA, Malik AH, Kamili AN, Singh CP, Khuroo AA. Patterns of floristic and functional diversity in two treeline ecotone sites of Kashmir Himalaya. ENVIRONMENTAL MONITORING AND ASSESSMENT 2022; 194:420. [PMID: 35543773 DOI: 10.1007/s10661-022-10044-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 04/09/2022] [Indexed: 06/15/2023]
Abstract
Globally, the treelines at higher elevations in mountains are reported to be advancing up-slope in response to recent climate warming. However, little is known about the treeline advancement in the Himalaya due to paucity of baseline vegetation data with which to compare, thus making their assessment and monitoring challenging. To fill this knowledge gap, the present study documented floristic and functional diversity of two treeline ecotone sites in Kashmir Himalaya. At each site, we conducted field sampling by laying five 20-m2 plots, with one at the highest limit (T0 plot), two plots below and two above the treeline and two nested subplots of 5-m2 for shrubs and five 1-m2 for herbs in each plot. We recorded 97 plant species belonging to 33 families from the two sites. We observed a considerable difference in species composition and distribution along the treeline ecotone. Majority of the species reported were perennial herbs. We observed a significant association of growth forms with the particular plots along the treeline ecotone. At both the sites, we recorded highest species richness at the T0 plot which was correlated well with the functional traits, thus indicating convergence of floristic and functional diversity at this transition zone. Interestingly, the T0 plot at both the sites showed maximum overlap of species with the plots above and below the treeline. In an era of climate warming, our study provides crucial baseline data that will facilitate assessment and monitoring of the Himalayan treelines.
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Affiliation(s)
- Aadil Gulzar
- Centre for Biodiversity & Taxonomy, Department of Botany, University of Kashmir, Srinagar, Jammu and Kashmir, 190 006, India
- Department of Environmental Science, University of Kashmir, Srinagar, Jammu and Kashmir, 190 006, India
| | - Maroof Hamid
- Centre for Biodiversity & Taxonomy, Department of Botany, University of Kashmir, Srinagar, Jammu and Kashmir, 190 006, India
| | - Firdous A Dar
- Centre for Biodiversity & Taxonomy, Department of Botany, University of Kashmir, Srinagar, Jammu and Kashmir, 190 006, India
| | - Sajad A Wani
- Centre for Biodiversity & Taxonomy, Department of Botany, University of Kashmir, Srinagar, Jammu and Kashmir, 190 006, India
| | - Akhtar H Malik
- Centre for Biodiversity & Taxonomy, Department of Botany, University of Kashmir, Srinagar, Jammu and Kashmir, 190 006, India
| | - Azra N Kamili
- Department of Environmental Science, University of Kashmir, Srinagar, Jammu and Kashmir, 190 006, India
- Department of Botany, Central University of Kashmir, Ganderbal, Jammu and Kashmir, 191 201, India
| | - C P Singh
- Space Applications Centre, Indian Space Research Organisation, Ahmedabad, 380 015, India
| | - Anzar Ahmad Khuroo
- Centre for Biodiversity & Taxonomy, Department of Botany, University of Kashmir, Srinagar, Jammu and Kashmir, 190 006, India.
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19
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Zou F, Tu C, Liu D, Yang C, Wang W, Zhang Z. Alpine Treeline Dynamics and the Special Exposure Effect in the Hengduan Mountains. FRONTIERS IN PLANT SCIENCE 2022; 13:861231. [PMID: 35463438 PMCID: PMC9024247 DOI: 10.3389/fpls.2022.861231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 03/07/2022] [Indexed: 06/14/2023]
Abstract
Alpine treeline is highly sensitive to climate change, but there remains a lack of research on the spatiotemporal heterogeneity of treeline and their relationships with climate change at the landscape scale. We extracted positions of alpine treeline from high-resolution Google Earth images from three periods (2000, 2010, and 2020) and analyzed the elevation patterns and dynamics of treeline positions in the Hengduan Mountains. Based on the treeline positions in 2020, a buffer zone of 300 m is established as the treeline transition zone, and the changing trend of the fraction vegetation cover (FVC) from 2000 to 2020 and its relationship with climate are also analyzed. Due to the special geographical and climatic environment, the treeline in the Hengduan Mountains area is high in the middle but lower in the surrounding areas. We found that over the past 20 years, the treeline position did not change significantly but that the FVC increased in 80.3% of the treeline areas. The increase in FVC was related to the decrease in precipitation in the growing season. The results also revealed a special exposure effect on the alpine treeline in the Hengduan Mountains. Because of the lower treeline, isotherm position caused by the monsoon climate, the treeline position on south-facing slopes is lower than that on slopes with other exposures. Our results confirmed that the pattern and dynamics of the alpine treeline are driven by the regional monsoon climate regime.
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Affiliation(s)
- Fuyan Zou
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, School of Ecology and Environmental Sciences, Yunnan University, Kunming, China
| | - Chengyi Tu
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, School of Ecology and Environmental Sciences, Yunnan University, Kunming, China
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, Berkeley, CA, United States
| | - Dongmei Liu
- Chinese Research Academy of Environmental Sciences, Beijing, China
| | - Chaoying Yang
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, School of Ecology and Environmental Sciences, Yunnan University, Kunming, China
| | - Wenli Wang
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, School of Ecology and Environmental Sciences, Yunnan University, Kunming, China
| | - Zhiming Zhang
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, School of Ecology and Environmental Sciences, Yunnan University, Kunming, China
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20
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Körner C. 'Fading of the temperature-growth coupling' in treeline trees reflects a conceptual bias. GLOBAL CHANGE BIOLOGY 2021; 27:3951-3952. [PMID: 34089549 DOI: 10.1111/gcb.15730] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Accepted: 05/26/2021] [Indexed: 06/12/2023]
Abstract
The global treeline phenomenon follows a common seasonal mean temperature (isotherm) of about 6°C. When the isotherm moves upslope because of rapid climatic warming, trees are left behind and are absent from the climatic tree limit. This commentary recalls the discrepancy between the actual uppermost position of trees and the potential (climatic) treeline. Temperature-based models can predict the potential treeline only (comment to Camarero et al., Global Change Biology, 27, 1879-1889, 2021). The photograph shows a treeline situation in SW New Zealand.
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Affiliation(s)
- Christian Körner
- Department of Environmental Sciences, Botany, University of Basel, Basel, Switzerland
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21
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Camarero JJ, Gazol A, Sánchez-Salguero R, Fajardo A, McIntire EJB, Liang E. Tree growth and treeline responses to temperature: Different questions and concepts. GLOBAL CHANGE BIOLOGY 2021; 27:e13-e14. [PMID: 34089540 DOI: 10.1111/gcb.15728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Accepted: 05/26/2021] [Indexed: 06/12/2023]
Abstract
Climate warming is expected to enhance tree growth at alpine treelines. A higher growth rate is forecasted as temperatures rise and growth becomes less dependent on the temperature rise. Since radial growth is just one component of treeline dynamics those forecasts do not necessarily apply to treeline elevation or latitude; treelines can shift upward or poleward or remain stable.
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Affiliation(s)
| | - Antonio Gazol
- Instituto Pirenaico de Ecología (IPE-CSIC), Zaragoza, Spain
| | - Raúl Sánchez-Salguero
- Instituto Pirenaico de Ecología (IPE-CSIC), Zaragoza, Spain
- Depto. de Sistemas Físicos, Químicos y Naturales, Universidad Pablo de Olavide, Sevilla, Spain
| | - Alex Fajardo
- Instituto de Investigación Interdisciplinario (I3), Universidad de Talca, Talca, Chile
| | | | - Eryuan Liang
- State Key Laboratory of Tibetan Plateau Earth System Science (LATPES), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China
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