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Yang Y, Shi Y, Wei X, Han J, Wang J, Mu C, Zhang J. Changes in mass allocation play a more prominent role than morphology in resource acquisition of the rhizomatous Leymus chinensis under drought stress. ANNALS OF BOTANY 2023; 132:121-132. [PMID: 37279964 PMCID: PMC10550271 DOI: 10.1093/aob/mcad073] [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: 12/08/2022] [Accepted: 06/05/2023] [Indexed: 06/08/2023]
Abstract
BACKGROUND AND AIMS Plants can respond to drought by changing their relative investments in the biomass and morphology of each organ. The aims of this study were to quantify the relative contribution of changes in morphology vs. allocation and determine how they affect each other. These results should help us understand the mechanisms that plants use to respond to drought events. METHODS In a glasshouse experiment, we applied a drought treatment (well-watered vs. drought) at early and late stages of plant growth, leading to four treatment combinations (well-watered in both early and late periods, WW; drought in the early period and well-watered in the late period, DW; well-watered in the early period and drought in the late period, WD; drought in both early and late periods, DD). We used the variance partitioning method to compare the contribution of organ (leaf and root) biomass allocation and morphology to the leaf area ratio, root length ratio and root area ratio, for the rhizomatous grass Leymus chinensis (Trin.) Tzvelev. KEY RESULTS Compared with the continuously well-watered treatment, the leaf area ratio, root length ratio and root area ratio showed increasing trends under various drought treatments. The contribution of leaf mass allocation to leaf area ratio differed among the drought treatments and was 2.1- to 5.3-fold greater than leaf morphology, and the contribution of root mass allocation to root length ratio was ~2-fold greater than that of root morphology. In contrast, root morphology contributed more to the root area ratio than biomass allocation under drought in both the early and late periods. There was a negative correlation between the ratio of leaf mass fraction to root mass fraction and the ratio of specific leaf area to specific root length (or specific root area). CONCLUSIONS This study suggested that organ biomass allocation drove a larger proportion of variation than morphological traits for the absorption of resources in this rhizomatous grass. These findings should help us understand the adaptive mechanisms of plants when they are confronted with drought stress.
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Affiliation(s)
- Yuheng Yang
- Institute of Grassland Science, Key Laboratory of Vegetation Ecology of the Ministry of Education, Jilin Songnen Grassland Ecosystem National Observation and Research Station, Northeast Normal University, Changchun 130024, China
| | - Yujie Shi
- Institute of Grassland Science, Key Laboratory of Vegetation Ecology of the Ministry of Education, Jilin Songnen Grassland Ecosystem National Observation and Research Station, Northeast Normal University, Changchun 130024, China
| | - Xiaowei Wei
- Institute of Grassland Science, Key Laboratory of Vegetation Ecology of the Ministry of Education, Jilin Songnen Grassland Ecosystem National Observation and Research Station, Northeast Normal University, Changchun 130024, China
| | - Jiayu Han
- Institute of Grassland Science, Key Laboratory of Vegetation Ecology of the Ministry of Education, Jilin Songnen Grassland Ecosystem National Observation and Research Station, Northeast Normal University, Changchun 130024, China
| | - Junfeng Wang
- Institute of Grassland Science, Key Laboratory of Vegetation Ecology of the Ministry of Education, Jilin Songnen Grassland Ecosystem National Observation and Research Station, Northeast Normal University, Changchun 130024, China
| | - Chunsheng Mu
- Institute of Grassland Science, Key Laboratory of Vegetation Ecology of the Ministry of Education, Jilin Songnen Grassland Ecosystem National Observation and Research Station, Northeast Normal University, Changchun 130024, China
| | - Jinwei Zhang
- Institute of Grassland Science, Key Laboratory of Vegetation Ecology of the Ministry of Education, Jilin Songnen Grassland Ecosystem National Observation and Research Station, Northeast Normal University, Changchun 130024, China
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Boardman L, Lockwood JL, Angilletta MJ, Krause JS, Lau JA, Loik ME, Simberloff D, Thawley CJ, Meyerson LA. The Future of Invasion Science Needs Physiology. Bioscience 2022. [DOI: 10.1093/biosci/biac080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Incorporating physiology into models of population dynamics will improve our understanding of how and why invasions succeed and cause ecological impacts, whereas others fail or remain innocuous. Targeting both organismal physiologists and invasion scientists, we detail how physiological processes affect every invasion stage, for both plants and animals, and how physiological data can be better used for studying the spatial dynamics and ecological effects of invasive species. We suggest six steps to quantify the physiological functions related to demography of nonnative species: justifying physiological traits of interest, determining ecologically appropriate time frames, identifying relevant abiotic variables, designing experimental treatments that capture covariation between abiotic variables, measuring physiological responses to these abiotic variables, and fitting statistical models to the data. We also provide brief guidance on approaches to modeling invasions. Finally, we emphasize the benefits of integrating research between communities of physiologists and invasion scientists.
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Affiliation(s)
- Leigh Boardman
- Department of Biological Sciences and with the Center for Biodiversity Research, University of Memphis , Memphis, Tennessee, United States
| | - Julie L Lockwood
- Department of Ecology, Evolution, and Natural Resources at Rutgers University , New Brunswick, New Jersey, United States
| | - Michael J Angilletta
- School of Life Sciences and with the Center for Learning Innovation in Science, Arizona State University , Tempe, Arizona, United States
| | - Jesse S Krause
- Department of Biology, University of Nevada , Reno, Nevada, United States
| | - Jennifer A Lau
- Department of Biology, Indiana University , Bloomington, Indian, United States
| | - Michael E Loik
- Environmental Studies Department, University of California , Santa Cruz, Santa Cruz, California, United States
| | - Daniel Simberloff
- Department of Ecology and Evolutionary Biology, University of Tennessee , Knoxville, Tennessee, United States
| | - Christopher J Thawley
- Department of Biological Sciences, University of Rhode Island , Kingston, Rhode Island, United States
| | - Laura A Meyerson
- Department of Natural Resources Science, University of Rhode Island , Kingston, Rhode Island, United States
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Stears AE, Adler PB, Blumenthal DM, Kray JA, Mueller KE, Ocheltree TW, Wilcox KR, Laughlin DC. Water availability dictates how plant traits predict demographic rates. Ecology 2022; 103:e3799. [PMID: 35724968 DOI: 10.1002/ecy.3799] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 04/17/2022] [Accepted: 04/21/2022] [Indexed: 11/08/2022]
Abstract
A major goal in ecology is to make generalizable predictions of organism responses to environmental variation based on their traits. However, straightforward relationships between traits and fitness are rare and likely vary with environmental context. Characterizing how traits mediate demographic responses to the environment may enhance predictions of organism responses to global change. We synthesized 15 years of demographic data and species-level traits in a shortgrass steppe to determine whether the effects of leaf and root traits on growth and survival depend on seasonal water availability. We predicted that (1) species with drought-tolerant traits, such as lower leaf turgor loss point (TLP) and higher leaf and root dry matter content (LDMC and RDMC), would be more likely to survive and grow in drier years due to higher wilting resistance, (2) these traits would not predict fitness in wetter years, and (3) traits that more directly measure physiological mechanisms of water use such as TLP would best predict demographic responses. We found that graminoids with more negative TLP and higher LDMC and RDMC had higher survival rates in drier years. Forbs demonstrated similar yet more variable responses. Graminoids grew larger in wetter years, regardless of traits. However, in both wet and dry years, graminoids with more negative TLP and higher LDMC and RDMC grew larger than less negative TLP and low LDMC and RDMC species. Traits significantly mediated the impact of drought on survival, but not growth, suggesting survival could be a stronger driver of species' drought response in this system. TLP predicted survival in drier years, but easier-to-measure LDMC and RDMC were equal or better predictors. These results advance our understanding of the mechanisms by which drought drives population dynamics, and show that abiotic context determines how traits drive fitness.
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Affiliation(s)
- Alice E Stears
- Botany Department and Program in Ecology, University of Wyoming, Laramie, WY
| | - Peter B Adler
- Department of Wildland Resources and the Ecology Center, Utah State University, Logan, UT
| | | | - Julie A Kray
- USDA-ARS Rangeland Resources Research Unit, Fort Collins, CO
| | - Kevin E Mueller
- Department of Biological, Geological and Environmental Sciences, Cleveland State University, Cleveland, OH
| | - Troy W Ocheltree
- Warner College of Natural Resources, Colorado State University, Fort Collins, CO
| | - Kevin R Wilcox
- Department of Ecosystem Science and Management, University of Wyoming, Laramie, WY
| | - Daniel C Laughlin
- Botany Department and Program in Ecology, University of Wyoming, Laramie, WY
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Holl KD, Luong JC, Brancalion PHS. Overcoming biotic homogenization in ecological restoration. Trends Ecol Evol 2022; 37:777-788. [PMID: 35660115 DOI: 10.1016/j.tree.2022.05.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 04/20/2022] [Accepted: 05/11/2022] [Indexed: 10/18/2022]
Abstract
Extensive evidence shows that regional (gamma) diversity is often lower across restored landscapes than in reference landscapes, in part due to common restoration practices that favor widespread species through selection of easily-grown species with high survival and propagation practices that reduce genetic diversity. We discuss approaches to counteract biotic homogenization, such as reintroducing species that are adapted to localized habitat conditions and are unlikely to colonize naturally; periodically reintroducing propagules from remnant populations to increase genetic diversity; and reintroducing higher trophic level fauna to restore interaction networks and processes that promote habitat heterogeneity. Several policy changes would also increase regional diversity; these include regional coordination amongst restoration groups, financial incentives to organizations producing conservation-valued species, and experimental designations for rare species introductions.
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Affiliation(s)
- Karen D Holl
- Environmental Studies Department, University of California, Santa Cruz, CA, 95064, USA.
| | - Justin C Luong
- Environmental Studies Department, University of California, Santa Cruz, CA, 95064, USA
| | - Pedro H S Brancalion
- Department of Forest Sciences, "Luiz de Queiroz" College of Agriculture, University of São Paulo, Piracicaba, SP, 13418-900, Brazil
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Luong JC, Loik ME. Adjustments in physiological and morphological traits suggest drought‐induced competitive release of some California plants. Ecol Evol 2022; 12:e8773. [PMID: 35386876 PMCID: PMC8975776 DOI: 10.1002/ece3.8773] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 03/14/2022] [Indexed: 11/11/2022] Open
Abstract
Drought and competition affect how morphological and physiological traits are expressed in plants. California plants were previously found to respond less negatively to resource limitation compared to invasive counterparts. In a glasshouse in Santa Cruz, CA, USA, we exposed five native California C3 grassland species to episodic drought and competition (via five locally invasive species). We hypothesized that leaf morphology would be more affected by competition, and leaf photosynthetic gas exchange more so by drought, consistent with optimal partitioning and environmental filter theories. We expected that traits would exhibit trade‐offs along a spectrum for resource conservatism versus acquisition. Bromus carinatus had greater photosynthetic recovery, while Diplacus aurantiacus had lower percent loss of net assimilation (PLA) and intrinsic water‐use efficiency (iWUE) during drought and competition simultaneously compared to just drought. Stipa pulchra and Sidalcea malviflora gas exchange was unaffected by drought, and leaf morphology exhibited drought‐related adjustments. Lupinus nanus exhibited trait adjustments for competition but not drought. Functional traits sorted onto two principal components related to trade‐offs for resource conservatism versus acquisition, and for above‐ versus belowground allocation. In summary, morphological traits were affected by competition and drought, whereas physiological traits, like leaf gas exchange, were primarily affected by drought. The grassland plants we studied showed diverse responses to drought and competition with trait trade‐offs related to resource conservatism versus acquisition, and for above‐ versus belowground allocation consistent with optimal partitioning and environmental filter theories. Diplacus aurantiacus experienced competitive release based on greater iWUE and lower PLA when facing drought and competition.
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Affiliation(s)
- Justin C. Luong
- Environmental Studies Department University of California, Santa Cruz Santa Cruz California USA
| | - Michael E. Loik
- Environmental Studies Department University of California, Santa Cruz Santa Cruz California USA
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Luong JC. Non‐periodic grassland restoration management can promote native woody shrub encroachment. Restor Ecol 2022. [DOI: 10.1111/rec.13650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Justin C. Luong
- Department of Environmental Studies University of California Santa Cruz, 1156 High Street Santa Cruz California 95064 USA
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