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Wang H, Wang R, Harrison SP, Prentice IC. Leaf morphological traits as adaptations to multiple climate gradients. J Ecol 2022; 110:1344-1355. [PMID: 35915621 PMCID: PMC9313568 DOI: 10.1111/1365-2745.13873] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Accepted: 02/15/2022] [Indexed: 06/12/2023]
Abstract
Leaf morphological traits vary systematically along climatic gradients. However, recent studies in plant functional ecology have mainly analysed quantitative traits, while numerical models of species distributions and vegetation function have focused on traits associated with resource acquisition; both ignore the wider functional significance of leaf morphology.A dataset comprising 22 leaf morphological traits for 662 woody species from 92 sites, representing all biomes present in China, was subjected to multivariate analysis in order to identify leading dimensions of trait covariation (correspondence analysis), quantify climatic and phylogenetic contributions (canonical correspondence analysis with variation partitioning) and characterise co-occurring trait syndromes (k-means clustering) and their climatic preferences.Three axes accounted for >20% of trait variation in both evergreen and deciduous species. Moisture index, precipitation seasonality and growing-season temperature explained 8%-10% of trait variation; family 15%-32%. Microphyll or larger, mid- to dark green leaves with drip tips in wetter climates contrasted with nanophyll or smaller glaucous leaves without drip tips in drier climates. Thick, entire leaves in less seasonal climates contrasted with thin, marginal dissected, aromatic and involute/revolute leaves in more seasonal climates. Thick, involute, hairy leaves in colder climates contrasted with thin leaves with marked surface structures (surface patterning) in warmer climates. Distinctive trait clusters were linked to the driest and most seasonal climates, for example the clustering of picophyll, fleshy and succulent leaves in the driest climates and leptophyll, linear, dissected, revolute or involute and aromatic leaves in regions with highly seasonal rainfall. Several trait clusters co-occurred in wetter climates, including clusters characterised by microphyll, moderately thick, patent and entire leaves or notophyll, waxy, dark green leaves. Synthesis. The plastic response of size, shape, colour and other leaf morphological traits to climate is muted, thus their apparent shift along climate gradients reflects plant adaptations to environment at a community level as determined by species replacement. Information on leaf morphological traits, widely available in floras, could be used to strengthen predictive models of species distribution and vegetation function.
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Affiliation(s)
- Han Wang
- Department of Earth System Science, Ministry of Education Key Laboratory for Earth System ModelingInstitute for Global Change Studies, Tsinghua UniversityBeijingChina
| | - Runxi Wang
- School of Biological SciencesUniversity of Hong KongHong Kong SARChina
| | - Sandy P. Harrison
- Department of Earth System Science, Ministry of Education Key Laboratory for Earth System ModelingInstitute for Global Change Studies, Tsinghua UniversityBeijingChina
- Department of Geography and Environmental ScienceUniversity of ReadingReadingUK
| | - Iain Colin Prentice
- Department of Earth System Science, Ministry of Education Key Laboratory for Earth System ModelingInstitute for Global Change Studies, Tsinghua UniversityBeijingChina
- Georgina Mace Centre for the Living Planet, Department of Life SciencesImperial College LondonAscotUK
- Department of Biological SciencesMacquarie UniversityNorth RydeNSWAustralia
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2
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Maurin KJL, Smissen RD, Lusk CH. A dated phylogeny shows Plio-Pleistocene climates spurred evolution of antibrowsing defences in the New Zealand flora. New Phytol 2022; 233:546-554. [PMID: 34610149 PMCID: PMC9298021 DOI: 10.1111/nph.17766] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 09/24/2021] [Indexed: 06/13/2023]
Abstract
Some plant traits may be legacies of coevolution with extinct megafauna. One example is the convergent evolution of 'divaricate' cage architectures in many New Zealand lineages, interpreted as a response to recently extinct flightless avian browsers whose ancestors arrived during the Paleogene period. Although experiments have confirmed that divaricate habit deters extant browsers, its abundance on frosty, droughty sites appears consistent with an earlier interpretation as a response to cold, dry Plio-Pleistocene climates. We used 45 protein-coding sequences from plastid genomes to reconstruct the evolutionary history of the divaricate habit in extant New Zealand lineages. Our dated phylogeny of 215 species included 91% of New Zealand eudicot divaricate species. We show that 86% of extant divaricate plants diverged from non-divaricate sisters within the last 5 Ma, implicating Plio-Pleistocene climates in the proliferation of cage architectures in New Zealand. Our results, combined with other recent findings, are consistent with the synthetic hypothesis that the browser-deterrent effect of cage architectures was strongly selected only when Plio-Pleistocene climatic constraints prevented woody plants from growing quickly out of reach of browsers. This is consistent with the abundance of cage architectures in other regions where plant growth is restricted by aridity or short frost-free periods.
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Affiliation(s)
| | - Rob D. Smissen
- Allan HerbariumManaaki Whenua – Landcare ResearchLincoln7640New Zealand
| | - Christopher H. Lusk
- Environmental Research InstituteThe University of WaikatoHamilton3240New Zealand
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3
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Beikircher B, Sack L, Ganthaler A, Losso A, Mayr S. Hydraulic-stomatal coordination in tree seedlings: tight correlation across environments and ontogeny in Acer pseudoplatanus. New Phytol 2021; 232:1297-1310. [PMID: 34176137 DOI: 10.1111/nph.17585] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 06/20/2021] [Indexed: 06/13/2023]
Abstract
Hydraulic conductance is recognized as a major determinant of gas exchange and productivity. However, whether this also applies to seedlings, a critically important stage for vegetation regeneration, has been largely unknown. We analyzed the hydraulic and stomatal conductance of leaves and shoots for 6-wk-old Acer pseudoplatanus seedlings emerging in different lowland and treeline habitats and under glasshouse conditions, respectively, as well as on 9-, 15- and 18-wk-old plants, and related findings to leaf and xylem anatomical traits. Treeline seedlings had higher leaf area-specific shoot hydraulic conductance (Kshoot-L ), and stomatal conductance (gs ), associated with wider xylem conduits, lower leaf area and higher stomatal density than lowland and glasshouse-grown plants. Across the first 18 wk of development, seedlings increased four-fold in absolute shoot hydraulic conductance (Kshoot ) and declined by half in Kshoot-L , with correlated shifts in xylem and leaf anatomy. Distal leaves had higher leaf hydraulic conductance (Kleaf ) and gs compared to basal leaves. Seedlings show strong variation across growth environments and ontogenetic shifts in hydraulic and anatomical parameters. Across growth sites, ontogenetic stages and leaf orders, gs was tightly correlated with Kshoot-L and Kleaf , balancing hydraulic supply with demand for the earliest stages of seedling establishment.
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Affiliation(s)
- Barbara Beikircher
- Department of Botany, University of Innsbruck, Sternwartestr. 15, Innsbruck, 6020, Austria
| | - Lawren Sack
- Department of Ecology and Evolutionary Biology, University of California (UCLA), 621 Charles E. Young Drive South, Los Angeles, CA, 90095, USA
| | - Andrea Ganthaler
- Department of Botany, University of Innsbruck, Sternwartestr. 15, Innsbruck, 6020, Austria
| | - Adriano Losso
- Department of Botany, University of Innsbruck, Sternwartestr. 15, Innsbruck, 6020, Austria
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, NSW, 2753, Australia
| | - Stefan Mayr
- Department of Botany, University of Innsbruck, Sternwartestr. 15, Innsbruck, 6020, Austria
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4
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Harrison SP, Cramer W, Franklin O, Prentice IC, Wang H, Brännström Å, de Boer H, Dieckmann U, Joshi J, Keenan TF, Lavergne A, Manzoni S, Mengoli G, Morfopoulos C, Peñuelas J, Pietsch S, Rebel KT, Ryu Y, Smith NG, Stocker BD, Wright IJ. Eco-evolutionary optimality as a means to improve vegetation and land-surface models. New Phytol 2021; 231:2125-2141. [PMID: 34131932 DOI: 10.1111/nph.17558] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [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: 01/17/2021] [Accepted: 05/25/2021] [Indexed: 06/12/2023]
Abstract
Global vegetation and land-surface models embody interdisciplinary scientific understanding of the behaviour of plants and ecosystems, and are indispensable to project the impacts of environmental change on vegetation and the interactions between vegetation and climate. However, systematic errors and persistently large differences among carbon and water cycle projections by different models highlight the limitations of current process formulations. In this review, focusing on core plant functions in the terrestrial carbon and water cycles, we show how unifying hypotheses derived from eco-evolutionary optimality (EEO) principles can provide novel, parameter-sparse representations of plant and vegetation processes. We present case studies that demonstrate how EEO generates parsimonious representations of core, leaf-level processes that are individually testable and supported by evidence. EEO approaches to photosynthesis and primary production, dark respiration and stomatal behaviour are ripe for implementation in global models. EEO approaches to other important traits, including the leaf economics spectrum and applications of EEO at the community level are active research areas. Independently tested modules emerging from EEO studies could profitably be integrated into modelling frameworks that account for the multiple time scales on which plants and plant communities adjust to environmental change.
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Affiliation(s)
- Sandy P Harrison
- Department of Geography and Environmental Science, University of Reading, Reading, RG6 6AB, UK
- Ministry of Education Key Laboratory for Earth System Modeling, Department of Earth System Science, Tsinghua University, Beijing, 100084, China
| | - Wolfgang Cramer
- Institut Méditerranéen de Biodiversité et d'Ecologie Marine et Continentale, Aix Marseille Université, CNRS, IRD, Avignon Université, Technopôle Arbois-Méditerranée, Aix-en-Provence Cedex 04, F-13545, France
| | - Oskar Franklin
- International Institute for Applied Systems Analysis, Schlossplatz 1, Laxenburg, 2361, Austria
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, 90183, Sweden
| | - Iain Colin Prentice
- Ministry of Education Key Laboratory for Earth System Modeling, Department of Earth System Science, Tsinghua University, Beijing, 100084, China
- Department of Life Sciences, Imperial College London, Silwood Park Campus, Buckhurst Road, Ascot, SL5 7PY, UK
- Department of Biological Sciences, Macquarie University, North Ryde, NSW, 2109, Australia
| | - Han Wang
- Ministry of Education Key Laboratory for Earth System Modeling, Department of Earth System Science, Tsinghua University, Beijing, 100084, China
| | - Åke Brännström
- International Institute for Applied Systems Analysis, Schlossplatz 1, Laxenburg, 2361, Austria
- Department of Mathematics and Mathematical Statistics, Umeå University, Umeå, 901 87, Sweden
| | - Hugo de Boer
- Copernicus Institute of Sustainable Development, Environmental Sciences, Faculty of Geosciences, Utrecht University, Vening Meinesz Building, Princetonlaan 8a, Utrecht, 3584 CB, the Netherlands
| | - Ulf Dieckmann
- International Institute for Applied Systems Analysis, Schlossplatz 1, Laxenburg, 2361, Austria
- Department of Evolutionary Studies of Biosystems, The Graduate University for Advanced Studies (Sokendai), Hayama, Kanagawa, 240-0193, Japan
| | - Jaideep Joshi
- International Institute for Applied Systems Analysis, Schlossplatz 1, Laxenburg, 2361, Austria
| | - Trevor F Keenan
- Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA, 94720, USA
- Department of Environmental Science, Policy and Management, University of California Berkeley, Berkeley, CA, 94720, USA
| | - Aliénor Lavergne
- Department of Physics, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK
| | - Stefano Manzoni
- Department of Physical Geography and Bolin Centre for Climate Research, Stockholm University, SE-106 91, Stockholm, Sweden
| | - Giulia Mengoli
- Department of Life Sciences, Imperial College London, Silwood Park Campus, Buckhurst Road, Ascot, SL5 7PY, UK
| | - Catherine Morfopoulos
- Department of Life Sciences, Imperial College London, Silwood Park Campus, Buckhurst Road, Ascot, SL5 7PY, UK
| | - Josep Peñuelas
- CSIC, Global Ecology, CREAF-CSIC-UAB, Bellaterra, Barcelona, Catalonia, 08193, Spain
- CREAF, Cerdanyola del Valles, Barcelona, Catalonia, 08193, Spain
| | - Stephan Pietsch
- International Institute for Applied Systems Analysis, Schlossplatz 1, Laxenburg, 2361, Austria
- BOKU - University of Life Sciences and Natural Resources, Gregor-Medel-Strasse 33, Vienna, 1180, Austria
| | - Karin T Rebel
- Copernicus Institute of Sustainable Development, Environmental Sciences, Faculty of Geosciences, Utrecht University, Vening Meinesz Building, Princetonlaan 8a, Utrecht, 3584 CB, the Netherlands
| | - Youngryel Ryu
- Department of Landscape Architecture and Rural Systems Engineering, Seoul National University, Seoul, 08826, South Korea
| | - Nicholas G Smith
- Department of Biological Sciences, Texas Tech University, 2901 Main Street, Lubbock, TX, 79409, USA
| | - Benjamin D Stocker
- Department of Environmental System Science, ETH, Universitätstrasse 2, Zürich, CH-8092, Switzerland
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zrcherstrasse 111, Birmensdorf, 8903, Switzerland
| | - Ian J Wright
- Department of Biological Sciences, Macquarie University, North Ryde, NSW, 2109, Australia
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Baird AS, Taylor SH, Pasquet-Kok J, Vuong C, Zhang Y, Watcharamongkol T, Scoffoni C, Edwards EJ, Christin PA, Osborne CP, Sack L. Developmental and biophysical determinants of grass leaf size worldwide. Nature 2021; 592:242-7. [PMID: 33762735 DOI: 10.1038/s41586-021-03370-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 02/18/2021] [Indexed: 02/01/2023]
Abstract
One of the most notable ecological trends-described more than 2,300 years ago by Theophrastus-is the association of small leaves with dry and cold climates, which has recently been recognized for eudicotyledonous plants at a global scale1-3. For eudicotyledons, this pattern has been attributed to the fact that small leaves have a thinner boundary layer that helps to avoid extreme leaf temperatures4 and their leaf development results in vein traits that improve water transport under cold or dry climates5,6. However, the global distribution of leaf size and its adaptive basis have not been tested in the grasses, which represent a diverse lineage that is distinct in leaf morphology and that contributes 33% of terrestrial primary productivity (including the bulk of crop production)7. Here we demonstrate that grasses have shorter and narrower leaves under colder and drier climates worldwide. We show that small grass leaves have thermal advantages and vein development that contrast with those of eudicotyledons, but that also explain the abundance of small leaves in cold and dry climates. The worldwide distribution of leaf size in grasses exemplifies how biophysical and developmental processes result in convergence across major lineages in adaptation to climate globally, and highlights the importance of leaf size and venation architecture for grass performance in past, present and future ecosystems.
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6
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Dong N, Prentice IC, Wright IJ, Evans BJ, Togashi HF, Caddy-Retalic S, McInerney FA, Sparrow B, Leitch E, Lowe AJ. Components of leaf-trait variation along environmental gradients. New Phytol 2020; 228:82-94. [PMID: 32198931 DOI: 10.1111/nph.16558] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [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: 11/10/2019] [Accepted: 03/12/2020] [Indexed: 05/16/2023]
Abstract
Leaf area (LA), mass per area (LMA), nitrogen per unit area (Narea ) and the leaf-internal to ambient CO2 ratio (χ) are fundamental traits for plant functional ecology and vegetation modelling. Here we aimed to assess how their variation, within and between species, tracks environmental gradients. Measurements were made on 705 species from 116 sites within a broad north-south transect from tropical to temperate Australia. Trait responses to environment were quantified using multiple regression; within- and between-species responses were compared using analysis of covariance and trait-gradient analysis. Leaf area, the leaf economics spectrum (indexed by LMA and Narea ) and χ (from stable carbon isotope ratios) varied almost independently among species. Across sites, however, χ and LA increased with mean growing-season temperature (mGDD0 ) and decreased with vapour pressure deficit (mVPD0 ) and soil pH. LMA and Narea showed the reverse pattern. Climate responses agreed with expectations based on optimality principles. Within-species variability contributed < 10% to geographical variation in LA but > 90% for χ, with LMA and Narea intermediate. These findings support the hypothesis that acclimation within individuals, adaptation within species and selection among species combine to create predictable relationships between traits and environment. However, the contribution of acclimation/adaptation vs species selection differs among traits.
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Affiliation(s)
- Ning Dong
- Department of Biological Sciences, Macquarie University, North Ryde, NSW, 2109, Australia
- Terrestrial Ecosystem Research Network, University of Sydney, Sydney, NSW, 2006, Australia
| | - Iain Colin Prentice
- Department of Biological Sciences, Macquarie University, North Ryde, NSW, 2109, Australia
- AXA Chair of Biosphere and Climate Impacts, Department of Life Sciences, Imperial College London, Silwood Park Campus, Ascot, SL5 7PY, UK
- Department of Earth System Science, Tsinghua University, Beijing, 100084, China
| | - Ian J Wright
- Department of Biological Sciences, Macquarie University, North Ryde, NSW, 2109, Australia
| | - Bradley J Evans
- Terrestrial Ecosystem Research Network, University of Sydney, Sydney, NSW, 2006, Australia
- Department of Sciences, School of Physical Sciences, University of Sydney, Sydney, NSW, 2006, Australia
| | - Henrique F Togashi
- Department of Biological Sciences, Macquarie University, North Ryde, NSW, 2109, Australia
- Terrestrial Ecosystem Research Network, University of Sydney, Sydney, NSW, 2006, Australia
| | - Stefan Caddy-Retalic
- School of Biological Sciences, University of Adelaide, North Terrace, Adelaide, SA, 5005, Australia
- Department for Environment and Water, Botanic Gardens and State Herbarium of South Australia, Hackney Road, Adelaide, SA, 5000, Australia
- School of Life and Environmental Sciences, University of Sydney, Sydney, NSW, Australia
| | - Francesca A McInerney
- Department of Earth Sciences, School of Physical Sciences, University of Adelaide, Adelaide, SA, 5005, Australia
| | - Ben Sparrow
- School of Biological Sciences, University of Adelaide, North Terrace, Adelaide, SA, 5005, Australia
- Terrestrial Ecosystem Research Network, University of Adelaide, Adelaide, SA, 5005, Australia
| | - Emrys Leitch
- School of Biological Sciences, University of Adelaide, North Terrace, Adelaide, SA, 5005, Australia
- Terrestrial Ecosystem Research Network, University of Adelaide, Adelaide, SA, 5005, Australia
| | - Andrew J Lowe
- School of Biological Sciences, University of Adelaide, North Terrace, Adelaide, SA, 5005, Australia
- Terrestrial Ecosystem Research Network, University of Adelaide, Adelaide, SA, 5005, Australia
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Fan X, Yan X, Qian C, Bachir DG, Yin X, Sun P, Ma XF. Leaf size variations in a dominant desert shrub, Reaumuria soongarica, adapted to heterogeneous environments. Ecol Evol 2020; 10:10076-10094. [PMID: 33005365 PMCID: PMC7520190 DOI: 10.1002/ece3.6668] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [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: 04/24/2020] [Revised: 07/16/2020] [Accepted: 07/20/2020] [Indexed: 11/07/2022] Open
Abstract
The climate in arid Central Asia (ACA) has changed rapidly in recent decades, but the ecological consequences of this are far from clear. To predict the impacts of climate change on ecosystem functioning, greater attention should be given to the relationships between leaf functional traits and environmental heterogeneity. As a dominant constructive shrub widely distributed in ACA, Reaumuria soongarica provided us with an ideal model to understand how leaf functional traits of desert ecosystems responded to the heterogeneous environments of ACA. Here, to determine the influences of genetic and ecological factors, we characterized species-wide variations in leaf traits among 30 wild populations of R. soongarica and 16 populations grown in a common garden. We found that the leaf length, width, and leaf length to width ratio (L/W) of the northern lineage were significantly larger than those of other genetic lineages, and principal component analysis based on the in situ environmental factors distinguished the northern lineage from the other lineages studied. With increasing latitude, leaf length, width, and L/W in the wild populations increased significantly. Leaf length and L/W were negatively correlated with altitude, and first increased and then decreased with increasing mean annual temperature (MAT) and mean annual precipitation (MAP). Stepwise regression analyses further indicated that leaf length variation was mainly affected by latitude. However, leaf width was uncorrelated with altitude, MAT, or MAP. The common garden trial showed that leaf width variation among the eastern populations was caused by both local adaptation and phenotypic plasticity. Our findings suggest that R. soongarica preferentially changes leaf length to adjust leaf size to cope with environmental change. We also reveal phenotypic evidence for ecological speciation of R. soongarica. These results will help us better understand and predict the consequences of climate change for desert ecosystem functioning.
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Affiliation(s)
- Xingke Fan
- Key Laboratory of Stress Physiology and Ecology in Cold and Arid Regions, Gansu Province Department of Ecology and Agriculture Research Northwest Institute of Eco-Environment and Resources Chinese Academy of Sciences Lanzhou China
- University of Chinese Academy of Sciences Beijing China
| | - Xia Yan
- School of Life Sciences Nantong University Nantong China
| | - Chaoju Qian
- Key Laboratory of Stress Physiology and Ecology in Cold and Arid Regions, Gansu Province Department of Ecology and Agriculture Research Northwest Institute of Eco-Environment and Resources Chinese Academy of Sciences Lanzhou China
| | - Daoura Goudia Bachir
- Key Laboratory of Stress Physiology and Ecology in Cold and Arid Regions, Gansu Province Department of Ecology and Agriculture Research Northwest Institute of Eco-Environment and Resources Chinese Academy of Sciences Lanzhou China
| | - Xiaoyue Yin
- Key Laboratory of Stress Physiology and Ecology in Cold and Arid Regions, Gansu Province Department of Ecology and Agriculture Research Northwest Institute of Eco-Environment and Resources Chinese Academy of Sciences Lanzhou China
- University of Chinese Academy of Sciences Beijing China
| | - Peipei Sun
- Key Laboratory of Stress Physiology and Ecology in Cold and Arid Regions, Gansu Province Department of Ecology and Agriculture Research Northwest Institute of Eco-Environment and Resources Chinese Academy of Sciences Lanzhou China
- University of Chinese Academy of Sciences Beijing China
| | - Xiao-Fei Ma
- Key Laboratory of Stress Physiology and Ecology in Cold and Arid Regions, Gansu Province Department of Ecology and Agriculture Research Northwest Institute of Eco-Environment and Resources Chinese Academy of Sciences Lanzhou China
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Lusk CH, Wiser SK, Laughlin DC. Macroclimate and Topography Interact to Influence the Abundance of Divaricate Plants in New Zealand. Front Plant Sci 2020; 11:507. [PMID: 32508852 PMCID: PMC7248281 DOI: 10.3389/fpls.2020.00507] [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] [Figures] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Accepted: 04/03/2020] [Indexed: 06/11/2023]
Abstract
The abundance of the divaricate growth form in New Zealand has been interpreted as either (a) the response of an isolated flora to cool, dry, Plio-Pleistocene climates; or (b) a defense against large browsing birds (moa) that were hunted to extinction shortly after human arrival during the last millennium. We used patterns of divaricate plant abundance across present-day landscapes to test a novel synthetic hypothesis: that the divaricate form is of most value to plants on fertile soils that attract herbivores, on sites where climatic constraints prevent plants from quickly growing out of the browse zone. This hypothesis predicts that divaricate species should be most abundant on terraces (landforms that are both fertile and frost-prone) in regions that are cold and dry, and should be scarce across all topographic positions in the warmest (largely frost-free) regions. To address our hypothesis, we first tested the influence of topography on frost regimes and nutrient levels by measuring temperatures and soil total C, N, and P at four standard topographic positions at five localities differing widely in macroclimate. We then extracted a dataset of 236 surveys comprising 9,877 relevé plots from the New Zealand National Vegetation Survey databank. We calculated the proportion of arborescent species with a divaricate growth form and the proportion of total arborescentcover contributed by divaricates on each plot; we then fitted linear mixed-effect models predicting these response variables as functions of topographic position and climate. The number of frosts recorded averaged <1 yr-1 at the warmest of the five sites studied, to >60 yr-1 on all topographic positions at the coldest site. Terraces were subject to more frequent and harder frosts than any other topographic position. Topography had no significant influence on total N or C:N, but total P was higher on terraces and in gullies than on faces or ridges. Frost-free period was the dominant influence on both species representation and cover of divaricate plants throughout the country. The effect of topography was also significant, but weaker. The effect of frost-free period was stronger on sites with water deficits than on sites where precipitation exceeded evapotranspiration. Divaricates made their largest contributions on terraces in cold, dry regions; as predicted, they were scarce on all topographic positions on sites with frost-free periods >300 days. Our hypothesis was generally supported, although the effect of topography on divaricate abundance was not as strong as some previous studies led us to expect. Divaricates made their largest contributions to arborescent species richness and cover on sites where climatic restrictions on growth coincide with relatively high nutrient availability. The contemporary distribution of the divaricate form across New Zealand landscapes thus appears to be reasonably well explained by the hypothesized interaction of climate and fertility-mediated browsing, although experiments may provide more conclusive tests of this hypothesis.
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Affiliation(s)
- Christopher H. Lusk
- Environmental Research Institute, University of Waikato, Hamilton, New Zealand
| | - Susan K. Wiser
- Manaaki Whenua – Landcare Research, Lincoln, New Zealand
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Rupp AIKS, Gruber P. Biomimetic Groundwork for Thermal Exchange Structures Inspired by Plant Leaf Design. Biomimetics (Basel) 2019; 4:E75. [PMID: 31783650 PMCID: PMC6963917 DOI: 10.3390/biomimetics4040075] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [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: 06/30/2019] [Revised: 11/13/2019] [Accepted: 11/20/2019] [Indexed: 01/19/2023] Open
Abstract
Geometry is a determining factor for thermal performance in both biological and technical systems. While biology has inspired thermal design before, biomimetic translation of leaf morphology into structural aspects of heat exchangers remains largely unaddressed. One determinant of plant thermal endurance against environmental exposure is leaf shape, which modulates the leaf boundary layer, transpiration, evaporative cooling, and convective exchange. Here, we lay the research groundwork for the extraction of design principles from leaf shape relations to heat and mass transfer. Leaf role models were identified from an extensive literature review on environmentally sensitive morphology patterns and shape-dependent exchange. Addressing canopy sun-shade dimorphism, sun leaves collected from multiple oak species exceeded significantly in margin extension and shape dissection. Abstracted geometries (i.e., elongated; with finely toothed edges; with few large-scale teeth) were explored with paper models of the same surface area in a controlled environment of minimal airflow, which is more likely to induce leaf thermal stress. For two model characteristic dimensions, evaporation rates were significantly faster for the dissected geometries. Shape-driven transfer enhancements were higher for the smaller models, and finely toothed edges reached local cooling up to 10 °C below air temperature. This investigation breaks new ground for solution-based biomimetics to inform the design of evaporation-assisted and passively enhanced thermal systems.
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Affiliation(s)
- Ariana I. K. S. Rupp
- Department of Biology, Biomimicry Research and Innovation Center, The University of Akron, Akron, OH 44325, USA
| | - Petra Gruber
- Myers School of Art and Department of Biology, Biomimicry Research and Innovation Center, The University of Akron, Akron, OH 44325, USA;
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Lusk CH, Grierson ERP, Laughlin DC. Large leaves in warm, moist environments confer an advantage in seedling light interception efficiency. New Phytol 2019; 223:1319-1327. [PMID: 30985943 DOI: 10.1111/nph.15849] [Citation(s) in RCA: 5] [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: 01/18/2019] [Accepted: 04/07/2019] [Indexed: 06/09/2023]
Abstract
Leaf size varies conspicuously along environmental gradients. Small leaves help plants cope with drought and frost, because of the effect of leaf size on boundary layer conductance; it is less clear what advantage large leaves confer in benign environments. We asked if large leaves give species of warm climates an advantage in seedling light interception efficiency over small-leaved species from colder environments. We measured seedling leaf, architectural and biomass distribution traits of 18 New Zealand temperate rainforest evergreens; we then used a 3-D digitiser and the Yplant program to model leaf area display and light interception. Species associated with mild climates on average had larger leaves and larger specific leaf areas (SLA) than those from cold climates, and displayed larger effective foliage areas per unit of aboveground biomass, indicating higher light interception efficiency at whole-plant level. This reflected differences in total foliage area, rather than in self-shading. Our findings advance the understanding of leaf size by showing that large leaves enable seedlings of species with highly conductive (but frost-sensitive) xylem to deploy large foliage areas without increasing self-shading. Leaf size variation along temperature gradients in humid forests may therefore reflect a trade-off between seedling light interception efficiency and susceptibility to frost.
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Affiliation(s)
- Christopher H Lusk
- Environmental Research Institute, University of Waikato, Private Bag 3105, Hamilton, 3240, New Zealand
| | - Ella R P Grierson
- The New Zealand Institute for Plant & Food Research, Sandringham 1142, Auckland, New Zealand
| | - Daniel C Laughlin
- Department of Botany, University of Wyoming, Laramie, WY, 82071, USA
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Biddick M, Hutton I, Burns KC. Independent evolution of allometric traits: a test of the allometric constraint hypothesis in island vines. Biol J Linn Soc Lond 2018. [DOI: 10.1093/biolinnean/bly158] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Matthew Biddick
- School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - Ian Hutton
- Lord Howe Island Museum, Lord Howe Island, NSW, Australia
| | - K C Burns
- School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand
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