1
|
Guzicka M, Marek S, Gawlak M, Tomaszewski D. Micromorphology of Pine Needle Primordia and Young Needles after Bud Dormancy Breaking. PLANTS (BASEL, SWITZERLAND) 2023; 12:913. [PMID: 36840261 PMCID: PMC9963322 DOI: 10.3390/plants12040913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 02/04/2023] [Accepted: 02/14/2023] [Indexed: 06/18/2023]
Abstract
Using a scanning electron microscope, the micromorphologies of needle primordia and the young needles of seven pine species (Pinus cembra, P. mugo, P. nigra, P. rigida, P. sylvestris, P. strobus, and P. uncinata) were analyzed at phenological stages B2 and B3 (according to Debazac). In B2, needle tips were rounded or pointed, depending on the species. In P. cembra and P. strobus, teeth were noted on the tips. Teeth were also visible on the margins in P. mugo, P. cembra, and P. strobus. Stomata became visible in the late B2 phase (P. sylvestris, P. mugo, and P. nigra) near the needle tips and were arranged in rows. In the B3 phase, needle tips were pointed. Only in P. strobus was the needle tip slightly rounded. The teeth on the margin in all the species were pointed. In P. strobus, their size and density along the margin decreased basipetally. In B3 for all the species, numerous stomata were visible. In P. sylvestris, P. cembra, and P. strobus, Florin rings were also observed. These observations could be useful in pine systematics but also in palaeobotanical or physiological studies. To the best of our knowledge, this is the first study on the micromorphology of very young needles in representatives of the genus Pinus.
Collapse
Affiliation(s)
- Marzenna Guzicka
- Institute of Dendrology of the Polish Academy of Sciences, Parkowa 5, PL-62-035 Kórnik, Poland
| | - Sławomir Marek
- Institute of Dendrology of the Polish Academy of Sciences, Parkowa 5, PL-62-035 Kórnik, Poland
| | - Magdalena Gawlak
- Institute of Plant Protection—National Research Institute, Władysława Węgorka 20, PL-60-318 Poznań, Poland
| | - Dominik Tomaszewski
- Institute of Dendrology of the Polish Academy of Sciences, Parkowa 5, PL-62-035 Kórnik, Poland
| |
Collapse
|
2
|
Gattmann M, McAdam SAM, Birami B, Link R, Nadal-Sala D, Schuldt B, Yakir D, Ruehr NK. Anatomical adjustments of the tree hydraulic pathway decrease canopy conductance under long-term elevated CO2. PLANT PHYSIOLOGY 2023; 191:252-264. [PMID: 36250901 PMCID: PMC9806622 DOI: 10.1093/plphys/kiac482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 09/24/2022] [Indexed: 06/16/2023]
Abstract
The cause of reduced leaf-level transpiration under elevated CO2 remains largely elusive. Here, we assessed stomatal, hydraulic, and morphological adjustments in a long-term experiment on Aleppo pine (Pinus halepensis) seedlings germinated and grown for 22-40 months under elevated (eCO2; c. 860 ppm) or ambient (aCO2; c. 410 ppm) CO2. We assessed if eCO2-triggered reductions in canopy conductance (gc) alter the response to soil or atmospheric drought and are reversible or lasting due to anatomical adjustments by exposing eCO2 seedlings to decreasing [CO2]. To quantify underlying mechanisms, we analyzed leaf abscisic acid (ABA) level, stomatal and leaf morphology, xylem structure, hydraulic efficiency, and hydraulic safety. Effects of eCO2 manifested in a strong reduction in leaf-level gc (-55%) not caused by ABA and not reversible under low CO2 (c. 200 ppm). Stomatal development and size were unchanged, while stomatal density increased (+18%). An increased vein-to-epidermis distance (+65%) suggested a larger leaf resistance to water flow. This was supported by anatomical adjustments of branch xylem having smaller conduits (-8%) and lower conduit lumen fraction (-11%), which resulted in a lower specific conductivity (-19%) and leaf-specific conductivity (-34%). These adaptations to CO2 did not change stomatal sensitivity to soil or atmospheric drought, consistent with similar xylem safety thresholds. In summary, we found reductions of gc under elevated CO2 to be reflected in anatomical adjustments and decreases in hydraulic conductivity. As these water savings were largely annulled by increases in leaf biomass, we do not expect alleviation of drought stress in a high CO2 atmosphere.
Collapse
Affiliation(s)
- Marielle Gattmann
- Institute of Meteorology and Climate Research – Atmospheric Environmental Research, Karlsruhe Institute of Technology, Garmisch-Partenkirchen 82467, Germany
| | - Scott A M McAdam
- Department of Botany and Plant Pathology, Purdue Center for Plant Biology, Purdue University, West Lafayette, Indiana 47907, USA
| | - Benjamin Birami
- Institute of Meteorology and Climate Research – Atmospheric Environmental Research, Karlsruhe Institute of Technology, Garmisch-Partenkirchen 82467, Germany
| | - Roman Link
- Ecophysiology and Vegetation Ecology, Julius-von-Sachs-Institute of Biological Sciences, University of Würzburg, Würzburg 97082, Germany
| | - Daniel Nadal-Sala
- Institute of Meteorology and Climate Research – Atmospheric Environmental Research, Karlsruhe Institute of Technology, Garmisch-Partenkirchen 82467, Germany
| | - Bernhard Schuldt
- Ecophysiology and Vegetation Ecology, Julius-von-Sachs-Institute of Biological Sciences, University of Würzburg, Würzburg 97082, Germany
| | - Dan Yakir
- Department of Environmental Sciences and Energy Research, Weizmann Institute of Science, Rehovot 76100, Israel
| | | |
Collapse
|
3
|
Marek S, Tomaszewski D, Żytkowiak R, Jasińska A, Zadworny M, Boratyńska K, Dering M, Danusevičius D, Oleksyn J, Wyka TP. Stomatal density in Pinus sylvestris as an indicator of temperature rather than CO 2 : Evidence from a pan-European transect. PLANT, CELL & ENVIRONMENT 2022; 45:121-132. [PMID: 34748220 DOI: 10.1111/pce.14220] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 10/13/2021] [Accepted: 10/28/2021] [Indexed: 05/15/2023]
Abstract
The commonly observed negative relationship between stomatal density (SD) and atmospheric CO2 has led to SD being proposed as an indicator of atmospheric CO2 concentration. The use of SD as a proxy for CO2 , however, has been hampered by an insufficient understanding of the intraspecific variation of this trait. We hypothesized that SD in Pinus sylvestris, a widely distributed conifer, varies geographically and that this variation is determined by major climatic variables. By sampling needles from naturally growing trees along a latitudinal range of 32.25°, equivalent to 13.7°C gradient of mean annual temperature (MAT) across Europe, we found that SD decreased from the warmest southern sites to the coldest sites in the north at a rate of 4 stomata per mm2 for each 1°C, with MAT explaining 44% of the variation. Additionally, samples from a provenance trial exhibited a positive relationship between SD and the MAT of the original localities, suggesting that high SD is an adaptation to warm temperature. Our study revealed one of the strongest intraspecific relationships between SD and climate in any woody species, supporting the utility of SD as a temperature, rather than direct CO2 , proxy. In addition, our results predict the response of SD to climate warming.
Collapse
Affiliation(s)
- Sławomir Marek
- Institute of Dendrology, Polish Academy of Sciences, Kórnik, Poland
| | | | - Roma Żytkowiak
- Institute of Dendrology, Polish Academy of Sciences, Kórnik, Poland
| | - Anna Jasińska
- Institute of Dendrology, Polish Academy of Sciences, Kórnik, Poland
| | - Marcin Zadworny
- Institute of Dendrology, Polish Academy of Sciences, Kórnik, Poland
| | | | | | - Darius Danusevičius
- Faculty of Forest Science and Ecology, Aleksandras Stulginskis University, Akademija, Kaunas, Lithuania
| | - Jacek Oleksyn
- Institute of Dendrology, Polish Academy of Sciences, Kórnik, Poland
| | - Tomasz P Wyka
- Faculty of Biology, Adam Mickiewicz University, Poznań, Poland
| |
Collapse
|
4
|
Haworth M, Marino G, Loreto F, Centritto M. Integrating stomatal physiology and morphology: evolution of stomatal control and development of future crops. Oecologia 2021; 197:867-883. [PMID: 33515295 PMCID: PMC8591009 DOI: 10.1007/s00442-021-04857-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 01/11/2021] [Indexed: 11/29/2022]
Abstract
Stomata are central players in the hydrological and carbon cycles, regulating the uptake of carbon dioxide (CO2) for photosynthesis and transpirative loss of water (H2O) between plants and the atmosphere. The necessity to balance water-loss and CO2-uptake has played a key role in the evolution of plants, and is increasingly important in a hotter and drier world. The conductance of CO2 and water vapour across the leaf surface is determined by epidermal and stomatal morphology (the number, size, and spacing of stomatal pores) and stomatal physiology (the regulation of stomatal pore aperture in response to environmental conditions). The proportion of the epidermis allocated to stomata and the evolution of amphistomaty are linked to the physiological function of stomata. Moreover, the relationship between stomatal density and [CO2] is mediated by physiological stomatal behaviour; species with less responsive stomata to light and [CO2] are most likely to adjust stomatal initiation. These differences in the sensitivity of the stomatal density—[CO2] relationship between species influence the efficacy of the ‘stomatal method’ that is widely used to infer the palaeo-atmospheric [CO2] in which fossil leaves developed. Many studies have investigated stomatal physiology or morphology in isolation, which may result in the loss of the ‘overall picture’ as these traits operate in a coordinated manner to produce distinct mechanisms for stomatal control. Consideration of the interaction between stomatal morphology and physiology is critical to our understanding of plant evolutionary history, plant responses to on-going climate change and the production of more efficient and climate-resilient food and bio-fuel crops.
Collapse
Affiliation(s)
- Matthew Haworth
- National Research Council of Italy, Institute of Sustainable Plant Protection (CNR-IPSP), Via Madonna del Piano 10, 50019, Sesto Fiorentino, FI, Italy.
| | - Giovanni Marino
- National Research Council of Italy, Institute of Sustainable Plant Protection (CNR-IPSP), Via Madonna del Piano 10, 50019, Sesto Fiorentino, FI, Italy
| | - Francesco Loreto
- Department of Biology, Agriculture and Food Sciences (CNR-DiSBA), National Research Council of Italy, Rome, Italy
- Department of Biology, University of Naples Federico II, Naples, Italy
| | - Mauro Centritto
- National Research Council of Italy, Institute of Sustainable Plant Protection (CNR-IPSP), Via Madonna del Piano 10, 50019, Sesto Fiorentino, FI, Italy
- ENI-CNR Water Research Center "Hypatia of Alexandria", Research Center Metapontum Agrobios, Metaponto, Italy
| |
Collapse
|
5
|
Reichgelt T, D'Andrea WJ. Plant carbon assimilation rates in atmospheric CO 2 reconstructions. THE NEW PHYTOLOGIST 2019; 223:1844-1855. [PMID: 31081929 DOI: 10.1111/nph.15914] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 05/08/2019] [Indexed: 06/09/2023]
Abstract
Fossil plant gas-exchange-based CO2 reconstructions use carbon (C) assimilation rates of extant plant species as substitutes for assimilation rates of fossil plants. However, assumptions in model species adoption can lead to systematic error propagation. We used a dataset of c. 2500 extant species to investigate the role of phylogenetic relatedness and ecology in determining C assimilation, an essential variable in gas-exchange-based CO2 models. We evaluated the effect on random and systematic error propagation in atmospheric CO2 caused by adopting different model species. Phylogenetic relatedness, growth form, and solar exposure are important predictors of C assimilation rate. CO2 reconstructions that apply C assimilation rates from modern species based solely on phylogenetic relatedness to fossil species can result in CO2 estimates that are systematically biased by a factor of > 2. C assimilation rates used in CO2 reconstructions should be determined by averaging assimilation rates of modern plant species that are (1) in the same family and (2) have a similar habit and habitat as the fossil plant. In addition, systematic bias potential and random error propagation are greatly reduced when CO2 is reconstructed from multiple fossil plant species with different modern relatives at the same site.
Collapse
Affiliation(s)
- Tammo Reichgelt
- Lamont-Doherty Earth Observatory, Columbia University, 61 Route 9W, Palisades, NY, 10964, USA
| | - William J D'Andrea
- Lamont-Doherty Earth Observatory, Columbia University, 61 Route 9W, Palisades, NY, 10964, USA
| |
Collapse
|
6
|
Hu JJ, Xing YW, Su T, Huang YJ, Zhou ZK. Stomatal frequency of Quercus glauca from three material sources shows the same inverse response to atmospheric pCO2. ANNALS OF BOTANY 2019; 123:1147-1158. [PMID: 30861064 PMCID: PMC6612940 DOI: 10.1093/aob/mcz020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 02/01/2019] [Indexed: 05/27/2023]
Abstract
BACKGROUND AND AIMS The inverse correlation between atmospheric CO2 partial pressure (pCO2) and stomatal frequency in many plants has been widely used to estimate palaeo-CO2 levels. However, apparent discrepancies exist among the obtained estimates. This study attempts to find a potential proxy for palaeo-CO2 concentrations by analysing the stomatal frequency of Quercus glauca (section Cyclobalanopsis, Fagaceae), a dominant species in East Asian sub-tropical forests with abundant fossil relatives. METHODS Stomatal frequencies of Q. glauca from three material sources were analysed: seedlings grown in four climatic chambers with elevated CO2 ranging from 400 to 1300 ppm; extant samples collected from 14 field sites at altitudes ranging from 142 to 1555 m; and 18 herbarium specimens collected between 1930 and 2011. Stomatal frequency-pCO2 correlations were determined using samples from these three sources. KEY RESULTS An inverse correlation between stomatal frequency and pCO2 was found for Q. glauca through cross-validation of the three material sources. The combined calibration curves integrating data of extant altitudinal samples and historical herbarium specimens improved the reliability and accuracy of the curves. However, materials in the climatic chambers exhibited a weak response and relatively high stomatal frequency possibly due to insufficient treatment time. CONCLUSIONS A new inverse stomatal frequency-pCO2 correlation for Q. glauca was determined using samples from three sources. These three material types show the same response, indicating that Q. glauca is sensitive to atmospheric pCO2 and is an ideal proxy for palaeo-CO2 levels. Quercus glauca is a nearest living relative (NLR) of section Cyclobalanopsis fossils, which are widely distributed in the strata of East Asia ranging from the Eocene to Pliocene, thereby providing excellent materials to reconstruct the atmospheric CO2 concentration history of the Cenozoic. Quercus glauca will add to the variety of proxies that can be widely used in addition to Ginkgo and Metasequoia.
Collapse
Affiliation(s)
- Jin-Jin Hu
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, China
| | - Yao-Wu Xing
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, China
| | - Tao Su
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, China
| | - Yong-Jiang Huang
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Zhe-Kun Zhou
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, China
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, China
| |
Collapse
|
7
|
Lang PLM, Willems FM, Scheepens JF, Burbano HA, Bossdorf O. Using herbaria to study global environmental change. THE NEW PHYTOLOGIST 2019; 221:110-122. [PMID: 30160314 PMCID: PMC6585664 DOI: 10.1111/nph.15401] [Citation(s) in RCA: 80] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Accepted: 07/19/2018] [Indexed: 05/14/2023]
Abstract
During the last centuries, humans have transformed global ecosystems. With their temporal dimension, herbaria provide the otherwise scarce long-term data crucial for tracking ecological and evolutionary changes over this period of intense global change. The sheer size of herbaria, together with their increasing digitization and the possibility of sequencing DNA from the preserved plant material, makes them invaluable resources for understanding ecological and evolutionary species' responses to global environmental change. Following the chronology of global change, we highlight how herbaria can inform about long-term effects on plants of at least four of the main drivers of global change: pollution, habitat change, climate change and invasive species. We summarize how herbarium specimens so far have been used in global change research, discuss future opportunities and challenges posed by the nature of these data, and advocate for an intensified use of these 'windows into the past' for global change research and beyond.
Collapse
Affiliation(s)
- Patricia L. M. Lang
- Research Group for Ancient Genomics and EvolutionMax Planck Institute for Developmental Biology72076TübingenGermany
| | - Franziska M. Willems
- Plant Evolutionary EcologyInstitute of Evolution and EcologyUniversity of Tübingen72076TübingenGermany
| | - J. F. Scheepens
- Plant Evolutionary EcologyInstitute of Evolution and EcologyUniversity of Tübingen72076TübingenGermany
| | - Hernán A. Burbano
- Research Group for Ancient Genomics and EvolutionMax Planck Institute for Developmental Biology72076TübingenGermany
| | - Oliver Bossdorf
- Plant Evolutionary EcologyInstitute of Evolution and EcologyUniversity of Tübingen72076TübingenGermany
| |
Collapse
|
8
|
Kim KW. Electron microscopic observations of stomata, epicuticular waxes, and papillae in Chamaecyparis obtusa: Reconsidering the traditional concept of Y-shaped white stomatal bands. Microsc Res Tech 2018; 81:716-723. [PMID: 29624793 DOI: 10.1002/jemt.23027] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 03/22/2018] [Indexed: 11/11/2022]
Abstract
The foliar morphological characters of hinoki (Chamaecyparis obtusa) were revisited using optical and scanning electron microscopy. In C. obtusa, typical Y-shaped white stomatal bands were evident on the abaxial leaf surfaces. Two facial leaves and two lateral leaves were observed at the same node. Waxy papillae and oval stomata were arranged in two or three rows with protuberant rims on the abaxial leaf surfaces. Higher magnifications revealed the deposition of epicuticular waxes (tubules) on the Y-shaped white stomatal bands. Given the absence of stomatal bands after dewaxing with organic solvents, the white stomatal bands in C. obtusa were related to the epicuticular waxes rather than the presence of aggregated stomata alone. In contrast to C. obtusa, a single median leaf and two lateral leaves were observed at the same node of oriental arborvitae (Platycladus koraiensis). Neither stomatal bands nor papillae were observed on P. koraiensis leaves. The stomatal density and epicuticular waxes in the stomatal regions of C. obtusa were higher than those of P. koraiensis. This study suggests that the traditional concept of Y-shaped white stomatal bands in C. obtusa should be revised to describe the arrangement of the aggregated waxy stomata that occur in rows.
Collapse
Affiliation(s)
- Ki Woo Kim
- School of Ecology and Environmental System, Kyungpook National University, Sangju, 37224, Korea.,Tree Diagnostic Center, Kyungpook National University, Sangju, 37224, Korea
| |
Collapse
|
9
|
Yan W, Zhong Y, Shangguan Z. Contrasting responses of leaf stomatal characteristics to climate change: a considerable challenge to predict carbon and water cycles. GLOBAL CHANGE BIOLOGY 2017; 23:3781-3793. [PMID: 28181733 DOI: 10.1111/gcb.13654] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Accepted: 01/20/2017] [Indexed: 05/03/2023]
Abstract
Stomata control the cycling of water and carbon between plants and the atmosphere; however, no consistent conclusions have been drawn regarding the response of stomatal frequency to climate change. Here, we conducted a meta-analysis of 1854 globally obtained data series to determine the response of stomatal frequency to climate change, which including four plant life forms (over 900 species), at altitudes ranging from 0 to 4500 m and over a time span of more than one hundred thousand years. Stomatal frequency decreased with increasing CO2 concentration and increased with elevated temperature and drought stress; it was also dependent on the species and experimental conditions. The response of stomatal frequency to climate change showed a trade-off between stomatal control strategies and environmental factors, such as the CO2 concentration, temperature, and soil water availability. Moreover, threshold effects of elevated CO2 and temperature on stomatal frequency were detected, indicating that the response of stomatal density to increasing CO2 concentration will decrease over the next few years. The results also suggested that the stomatal index may be more reliable than stomatal density for determination of the historic CO2 concentration. Our findings indicate that the contrasting responses of stomata to climate change bring a considerable challenge in predicting future water and carbon cycles.
Collapse
Affiliation(s)
- Weiming Yan
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Yangquanwei Zhong
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, Shaanxi, 712100, China
- Center for Ecological and Environmental Sciences, Key Laboratory for Space Bioscience and Biotechnology, Northwestern Polytechnical University, Xi'an, 710072, China
| | - Zhouping Shangguan
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, Shaanxi, 712100, China
| |
Collapse
|
10
|
Does plant size affect growth responses to water availability at glacial, modern and future CO2 concentrations? Ecol Res 2016. [DOI: 10.1007/s11284-015-1330-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
11
|
Haworth M, Killi D, Materassi A, Raschi A. Coordination of stomatal physiological behavior and morphology with carbon dioxide determines stomatal control. AMERICAN JOURNAL OF BOTANY 2015; 102:677-88. [PMID: 26022482 DOI: 10.3732/ajb.1400508] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Accepted: 03/30/2015] [Indexed: 05/08/2023]
Abstract
PREMISE OF THE STUDY Stomatal control is determined by the ability to alter stomatal aperture and/or the number of stomata on the surface of new leaves in response to growth conditions. The development of stomatal control mechanisms to the concentration of CO₂within the atmosphere ([CO₂]) is fundamental to our understanding of plant evolutionary history and the prediction of gas exchange responses to future [CO₂]. METHODS In a controlled environment, fern and angiosperm species were grown in atmospheres of ambient (400 ppm) and elevated (2000 ppm) [CO₂]. Physiological stomatal behavior was compared with the stomatal morphological response to [CO₂]. KEY RESULTS An increase in [CO₂] or darkness induced physiological stomatal responses ranging from reductions (active) to no change (passive) in stomatal conductance. Those species with passive stomatal behavior exhibited pronounced reductions of stomatal density in new foliage when grown in elevated [CO₂], whereas species with active stomata showed little morphological response to [CO₂]. Analysis of the physiological and morphological stomatal responses of a wider range of species suggests that patterns of stomatal control to [CO₂] do not follow a phylogenetic pattern associated with plant evolution. CONCLUSIONS Selective pressures may have driven the development of divergent stomatal control strategies to increased [CO₂]. Those species that are able to actively regulate guard cell turgor are more likely to respond to [CO₂] through a change in stomatal aperture than stomatal number. We propose a model of stomatal control strategies in response to [CO₂] characterized by a trade-off between short-term physiological behavior and longer-term morphological response.
Collapse
Affiliation(s)
- Matthew Haworth
- CNR-Istituto di Biometeorologia (IBIMET), Via Giovanni Caproni 8 50145 Florence, Italy
| | - Dilek Killi
- Department of Agrifood Production and Environmental Sciences (DiSPAA), University of Florence, Piazzale delle Cascine 28 50144 Florence, Italy Institute of Natural and Applied Science, Çanakkale Onsekiz Mart University 17020 Çanakkale, Turkey
| | - Alessandro Materassi
- CNR-Istituto di Biometeorologia (IBIMET), Via Giovanni Caproni 8 50145 Florence, Italy
| | - Antonio Raschi
- CNR-Istituto di Biometeorologia (IBIMET), Via Giovanni Caproni 8 50145 Florence, Italy
| |
Collapse
|
12
|
Hu JJ, Xing YW, Turkington R, Jacques FMB, Su T, Huang YJ, Zhou ZK. A new positive relationship between pCO2 and stomatal frequency in Quercus guyavifolia (Fagaceae): a potential proxy for palaeo-CO2 levels. ANNALS OF BOTANY 2015; 115:777-88. [PMID: 25681824 PMCID: PMC4373289 DOI: 10.1093/aob/mcv007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Revised: 12/02/2014] [Accepted: 01/05/2015] [Indexed: 05/11/2023]
Abstract
BACKGROUND AND AIMS The inverse relationship between atmospheric CO2 partial pressure (pCO2) and stomatal frequency in many species of plants has been widely used to estimate palaeoatmospheric CO2 (palaeo-CO2) levels; however, the results obtained have been quite variable. This study attempts to find a potential new proxy for palaeo-CO2 levels by analysing stomatal frequency in Quercus guyavifolia (Q. guajavifolia, Fagaceae), an extant dominant species of sclerophyllous forests in the Himalayas with abundant fossil relatives. METHODS Stomatal frequency was analysed for extant samples of Q. guyavifolia collected from17 field sites at altitudes ranging between 2493 and 4497 m. Herbarium specimens collected between 1926 and 2011 were also examined. Correlations of pCO2-stomatal frequency were determined using samples from both sources, and these were then applied to Q. preguyavaefolia fossils in order to estimate palaeo-CO2 concentrations for two late-Pliocene floras in south-western China. KEY RESULTS In contrast to the negative correlations detected for most other species that have been studied, a positive correlation between pCO2 and stomatal frequency was determined in Q. guyavifolia sampled from both extant field collections and historical herbarium specimens. Palaeo-CO2 concentrations were estimated to be approx. 180-240 ppm in the late Pliocene, which is consistent with most other previous estimates. CONCLUSIONS A new positive relationship between pCO2 and stomatal frequency in Q. guyavifolia is presented, which can be applied to the fossils closely related to this species that are widely distributed in the late-Cenozoic strata in order to estimate palaeo-CO2 concentrations. The results show that it is valid to use a positive relationship to estimate palaeo-CO2 concentrations, and the study adds to the variety of stomatal density/index relationships that available for estimating pCO2. The physiological mechanisms underlying this positive response are unclear, however, and require further research.
Collapse
Affiliation(s)
- Jin-Jin Hu
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China, Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla 666303, China, Institute of Systematic Botany, University of Zürich, Zürich 8008, Switzerland, Department of Botany, and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4 and University of Chinese Academy of Sciences, Beijing 100049, China Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China, Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla 666303, China, Institute of Systematic Botany, University of Zürich, Zürich 8008, Switzerland, Department of Botany, and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4 and University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yao-Wu Xing
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China, Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla 666303, China, Institute of Systematic Botany, University of Zürich, Zürich 8008, Switzerland, Department of Botany, and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4 and University of Chinese Academy of Sciences, Beijing 100049, China
| | - Roy Turkington
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China, Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla 666303, China, Institute of Systematic Botany, University of Zürich, Zürich 8008, Switzerland, Department of Botany, and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4 and University of Chinese Academy of Sciences, Beijing 100049, China
| | - Frédéric M B Jacques
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China, Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla 666303, China, Institute of Systematic Botany, University of Zürich, Zürich 8008, Switzerland, Department of Botany, and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4 and University of Chinese Academy of Sciences, Beijing 100049, China
| | - Tao Su
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China, Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla 666303, China, Institute of Systematic Botany, University of Zürich, Zürich 8008, Switzerland, Department of Botany, and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4 and University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yong-Jiang Huang
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China, Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla 666303, China, Institute of Systematic Botany, University of Zürich, Zürich 8008, Switzerland, Department of Botany, and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4 and University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhe-Kun Zhou
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China, Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla 666303, China, Institute of Systematic Botany, University of Zürich, Zürich 8008, Switzerland, Department of Botany, and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4 and University of Chinese Academy of Sciences, Beijing 100049, China Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China, Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla 666303, China, Institute of Systematic Botany, University of Zürich, Zürich 8008, Switzerland, Department of Botany, and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4 and University of Chinese Academy of Sciences, Beijing 100049, China
| |
Collapse
|
13
|
Bai YJ, Chen LQ, Ranhotra PS, Wang Q, Wang YF, Li CS. Reconstructing atmospheric CO2 during the Plio-Pleistocene transition by fossil Typha. GLOBAL CHANGE BIOLOGY 2015; 21:874-81. [PMID: 24990109 DOI: 10.1111/gcb.12670] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Accepted: 06/16/2014] [Indexed: 05/27/2023]
Abstract
The Earth has undergone a significant climate switch from greenhouse to icehouse during the Plio-Pleistocene transition (PPT) around 2.7-2.4 million years ago (Ma), marked by the intensification of the Northern Hemisphere glaciation (NHG) ~2.7 Ma. Evidence based on oceanic CO2 [(CO2)aq], supposed to be in close equilibrium with the atmospheric CO2 [(CO2)atm], suggests that the CO2 decline might drive such climate cooling. However, the rarity of direct evidence from [CO2]atm during the interval prevents determination of the atmospheric CO2 level and further assessment on the impact of its fluctuation. Here, we reconstruct the [CO2]atm level during 2.77-2.52 Ma based on a new developed proxy of stomatal index on Typha orientalis leaves from Shanxi, North China, and depict the first [CO2]atm curve over the past 5 Ma by using stomata-based [CO2]atm data. Comparisons of the terrestrial-based [CO2]atm and the existed marine-based [CO2]aq curves show a similar general trend but with different intensity of fluctuations. Our data reveal that the high peak of [CO2]atm occurred at 2.77-2.52 Ma with a lower [CO2]aq background. The subsequent sharp fall in [CO2]atm level might be responsible for the intensification of the NHG based on their general temporal synchronism. These findings shed a significant light for our understanding toward the [CO2]atm changes and its ecological impact since 5 Ma.
Collapse
Affiliation(s)
- Yun-Jun Bai
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | | | | | | | | | | |
Collapse
|
14
|
Drake BG. Rising sea level, temperature, and precipitation impact plant and ecosystem responses to elevated CO2 on a Chesapeake Bay wetland: review of a 28-year study. GLOBAL CHANGE BIOLOGY 2014; 20:3329-3343. [PMID: 24820033 DOI: 10.1111/gcb.12631] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Accepted: 02/25/2014] [Indexed: 06/03/2023]
Abstract
An ongoing field study of the effects of elevated atmospheric CO2 on a brackish wetland on Chesapeake Bay, started in 1987, is unique as the longest continually running investigation of the effects of elevated CO2 on an ecosystem. Since the beginning of the study, atmospheric CO2 increased 18%, sea level rose 20 cm, and growing season temperature varied with approximately the same range as predicted for global warming in the 21st century. This review looks back at this study for clues about how the effects of rising sea level, temperature, and precipitation interact with high atmospheric CO2 to alter the physiology of C3 and C4 photosynthetic species, carbon assimilation, evapotranspiration, plant and ecosystem nitrogen, and distribution of plant communities in this brackish wetland. Rising sea level caused a shift to higher elevations in the Scirpus olneyi C3 populations on the wetland, displacing the Spartina patens C4 populations. Elevated CO2 stimulated carbon assimilation in the Scirpus C3 species measured by increased shoot and root density and biomass, net ecosystem production, dissolved organic and inorganic carbon, and methane production. But elevated CO2 also decreased biomass of the grass, S. patens C4. The elevated CO2 treatment reduced tissue nitrogen concentration in shoots, roots, and total canopy nitrogen, which was associated with reduced ecosystem respiration. Net ecosystem production was mediated by precipitation through soil salinity: high salinity reduced the CO2 effect on net ecosystem production, which was zero in years of severe drought. The elevated CO2 stimulation of shoot density in the Scirpus C3 species was sustained throughout the 28 years of the study. Results from this study suggest that rising CO2 can add substantial amounts of carbon to ecosystems through stimulation of carbon assimilation, increased root exudates to supply nitrogen fixation, reduced dark respiration, and improved water and nitrogen use efficiency.
Collapse
Affiliation(s)
- Bert G Drake
- Smithsonian Environmental Research Center, PO Box 28, Edgewater, MD, 21037, USA
| |
Collapse
|
15
|
Laacouri A, Nater EA, Kolka RK. Distribution and uptake dynamics of mercury in leaves of common deciduous tree species in Minnesota, U.S.A. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:10462-70. [PMID: 23962151 DOI: 10.1021/es401357z] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
A sequential extraction technique for compartmentalizing mercury (Hg) in leaves was developed based on a water extraction of Hg from the leaf surface followed by a solvent extraction of the cuticle. The bulk of leaf Hg was found in the tissue compartment (90-96%) with lesser amounts in the surface and cuticle compartments. Total leaf concentrations of Hg varied among species and was most closely correlated with the number of stomates per sample, supporting the hypothesis that stomatal uptake of atmospheric Hg (most likely Hg(0)) is a potential uptake pathway. Mercury concentrations in leaves were monitored from emergence to senescence and showed a strong positive correlation with leaf age. Leaves accumulated Hg throughout the growing season; the highest uptake rates coincided with periods of high photosynthetic activity. Concentrations of Hg in leaf tissue increased steadily throughout the season, but no such trends were observed for surficial or cuticular accumulation. Factors affecting the variability of Hg in leaves were analyzed to improve protocols for the potential use of leaves as passive monitors of atmospheric Hg. Results show that total leaf Hg concentrations are affected by leaf age and leaf placement in the crown.
Collapse
Affiliation(s)
- Aicam Laacouri
- Department of Soil, Water, and Climate, University of Minnesota , 439 Borlaug Hall, 1991 Upper Buford Circle, St. Paul, Minnesota 55108-6028, United States
| | | | | |
Collapse
|
16
|
Leaf area and water content changes after permanent and temporary storage. PLoS One 2012; 7:e42604. [PMID: 22880051 PMCID: PMC3411807 DOI: 10.1371/journal.pone.0042604] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2012] [Accepted: 07/09/2012] [Indexed: 11/20/2022] Open
Abstract
Accurate measurements of leaf morphology must be taken to develop models of ecosystem productivity and climate change projections. Once leaves are removed from a plant they begin to lose water and degrade. If specimens cannot be measured immediately after harvest, it is important to store the leaves in a manner that reduces morphological changes. If preserved specimens are used, estimates that closely match fresh measurements need to be calculated. This study examined the change in leaf area after storage treatments and developed models that can be used to more accurately estimate initial leaf area. Fresh leaf area was measured from ten plant species then stored in one of two common storage treatments. After storage, leaf area was re-measured and comparisons were made between species and growth forms. Leaf area decreased the most after permanent storage treatments and the least after temporary storage. Pressed leaves shrunk over 18% while cold storage leaves shrunk under 4%. The woody dicot growth form shrunk the least in all treatments. Shrinkage was positively correlated with initial water content and dissection index, a measure of leaf shape and complexity.
Collapse
|
17
|
Barkworth ME, Murrell ZE. The US Virtual Herbarium: working with individual herbaria to build a national resource. Zookeys 2012:55-73. [PMID: 22859878 PMCID: PMC3406466 DOI: 10.3897/zookeys.209.3205] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2012] [Accepted: 06/25/2012] [Indexed: 11/12/2022] Open
Abstract
The goal of the US Virtual Herbarium (USVH) project is to digitize (database, image, georeference) all specimens in all US herbaria, enabling them to be made available through a single portal. Herbaria house specimens of plants, fungi, and algae, so USVH will offer a rich portrait of biodiversity in the US and in the other countries represented in US herbaria. Equally importantly, working towards this goal will engage people with herbaria and the organisms they house, expanding their appreciation of both the power of biodiversity informatics and the demands that it places on data providers while developing improved communication among those working in and with herbaria. The project is not funded but has strong support among those working in herbaria. It works through regional herbarium networks, some of which existed prior to the USVH project, while others are still in gestation. It differs from most digitization projects in its emphasis on helping those involved with herbaria become part of a national enterprise, an aspect that is seen as critical to creating the resources needed to develop and sustain the project. In this paper, we present some of the lessons we have learned and the difficulties we have encountered during the first few years of the project.
Collapse
Affiliation(s)
- Mary E Barkworth
- Intermountain Herbarium, Department of Biology, Utah State University, 5305 Old Main Hill, Logan, Utah, USA 84322-5305
| | | |
Collapse
|
18
|
Haworth M, Elliott-Kingston C, McElwain JC. Co-ordination of physiological and morphological responses of stomata to elevated [CO2] in vascular plants. Oecologia 2012; 171:71-82. [PMID: 22810089 DOI: 10.1007/s00442-012-2406-9] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2012] [Accepted: 06/19/2012] [Indexed: 10/28/2022]
Abstract
Plant stomata display a wide range of short-term behavioural and long-term morphological responses to atmospheric carbon dioxide concentration ([CO(2)]). The diversity of responses suggests that plants may have different strategies for controlling gas exchange, yet it is not known whether these strategies are co-ordinated in some way. Here, we test the hypothesis that there is co-ordination of physiological (via aperture change) and morphological (via stomatal density change) control of gas exchange by plants. We examined the response of stomatal conductance (G(s)) to instantaneous changes in external [CO(2)] (C(a)) in an evolutionary cross-section of vascular plants grown in atmospheres of elevated [CO(2)] (1,500 ppm) and sub-ambient [O(2)] (13.0 %) compared to control conditions (380 ppm CO(2), 20.9 % O(2)). We found that active control of stomatal aperture to [CO(2)] above current ambient levels was not restricted to angiosperms, occurring in the gymnosperms Lepidozamia peroffskyana and Nageia nagi. The angiosperm species analysed appeared to possess a greater respiratory demand for stomatal movement than gymnosperm species displaying active stomatal control. Those species with little or no control of stomatal aperture (termed passive) to C(a) were more likely to exhibit a reduction in stomatal density than species with active stomatal control when grown in atmospheres of elevated [CO(2)]. The relationship between the degree of stomatal aperture control to C(a) above ambient and the extent of any reduction in stomatal density may suggest the co-ordination of physiological and morphological responses of stomata to [CO(2)] in the optimisation of water use efficiency. This trade-off between stomatal control strategies may have developed due to selective pressures exerted by the costs associated with passive and active stomatal control.
Collapse
|
19
|
Jordan GJ. A critical framework for the assessment of biological palaeoproxies: predicting past climate and levels of atmospheric CO(2) from fossil leaves. THE NEW PHYTOLOGIST 2011; 192:29-44. [PMID: 21770947 DOI: 10.1111/j.1469-8137.2011.03829.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
This review uses proxies of past temperature and atmospheric CO(2) composition based on fossil leaves to illustrate the uncertainties in biologically based proxies of past environments. Most leaf-based proxies are geographically local or genetically restricted and therefore can be confounded by evolution, extinction, changes in local environment or immigration of species. Stomatal frequency proxies illustrate how genetically restricted proxies can be particularly vulnerable to evolutionary change. High predictive power in the modern world resulting from the use of a very narrow calibration cannot be confidently extrapolated into the past (the Ginkgo paradox). Many foliar physiognomic proxies of climate are geographically local and use traits that are more or less fixed for individual species. Such proxies can therefore be confounded by floristic turnover and biome shifts in the region of calibration. Uncertainty in proxies tends to be greater for more ancient fossils. I present a set of questions that should be considered before using a proxy. Good proxies should be relatively protected from environmental and genetic change, particularly through having high information content and being founded on biomechanical or biochemical principles. Some current and potential developments are discussed, including those that involve more mechanistically sound proxies and better use of multivariate approaches.
Collapse
Affiliation(s)
- Gregory J Jordan
- School of Plant Science, University of Tasmania, Private Bag 55, Hobart, Tas. 7001, Australia
| |
Collapse
|
20
|
Haworth M, Elliott-Kingston C, McElwain JC. Stomatal control as a driver of plant evolution. JOURNAL OF EXPERIMENTAL BOTANY 2011; 62:2419-23. [PMID: 21576397 DOI: 10.1093/jxb/err086] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Affiliation(s)
- Matthew Haworth
- School of Biology and Environmental Science, University College Dublin, Belfield, Dublin 4, Ireland.
| | | | | |
Collapse
|
21
|
Haworth M, Elliott-Kingston C, McElwain JC. The stomatal CO2 proxy does not saturate at high atmospheric CO2 concentrations: evidence from stomatal index responses of Araucariaceae conifers. Oecologia 2011; 167:11-9. [DOI: 10.1007/s00442-011-1969-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2010] [Accepted: 03/08/2011] [Indexed: 10/18/2022]
|
22
|
Abstract
This review examines the evolution of the plant vascular system from its beginnings in the green algae to modern arborescent plants, highlighting the recent advances in developmental, organismal, geochemical and climatological research that have contributed to our understanding of the evolution of xylem. Hydraulic trade-offs in vascular structure-function are discussed in the context of canopy support and drought and freeze-thaw stress resistance. This qualitative and quantitative neontological approach to palaeobotany may be useful for interpreting the water-transport efficiencies and hydraulic limits in fossil plants. Large variations in atmospheric carbon dioxide levels are recorded in leaf stomatal densities, and may have had profound impacts on the water conservation strategies of ancient plants. A hypothesis that links vascular function with stomatal density is presented and examined in the context of the evolution of wood and/or vessels. A discussion of the broader impacts of plant transport on hydrology and climate concludes this review.
Collapse
Affiliation(s)
- J Pittermann
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, USA.
| |
Collapse
|
23
|
Haworth M, Heath J, McElwain JC. Differences in the response sensitivity of stomatal index to atmospheric CO2 among four genera of Cupressaceae conifers. ANNALS OF BOTANY 2010; 105:411-8. [PMID: 20089556 PMCID: PMC2826259 DOI: 10.1093/aob/mcp309] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2009] [Revised: 11/05/2009] [Accepted: 12/03/2009] [Indexed: 05/07/2023]
Abstract
BACKGROUND AND AIMS The inverse relationship between stomatal density (SD: number of stomata per mm(2) leaf area) and atmospheric concentration of CO2 ([CO2]) permits the use of plants as proxies of palaeo-atmospheric CO2. Many stomatal reconstructions of palaeo-[CO2] are based upon multiple fossil species. However, it is unclear how plants respond to [CO2] across genus, family or ecotype in terms of SD or stomatal index (SI: ratio of stomata to epidermal cells). This study analysed the stomatal numbers of conifers from the ancient family Cupressaceae, in order to examine the nature of the SI-[CO2] relationship, and potential implications for stomatal reconstructions of palaeo-[CO2]. Methods Stomatal frequency measurements were taken from historical herbarium specimens of Athrotaxis cupressoides, Tetraclinis articulata and four Callitris species, and live A. cupressoides grown under CO2-enrichment (370, 470, 570 and 670 p.p.m. CO2). KEY RESULTS T. articulata, C. columnaris and C. rhomboidea displayed significant reductions in SI with rising [CO2]; by contrast, A. cupressoides, C. preissii and C. oblonga show no response in SI. However, A. cupressoides does reduce SI to increases in [CO2] above current ambient (approx. 380 p.p.m. CO2). This dataset suggests that a shared consistent SI-[CO2] relationship is not apparent across the genus Callitris. Conclusions The present findings suggest that it is not possible to generalize how conifer species respond to fluctuations in [CO2] based upon taxonomic relatedness or habitat. This apparent lack of a consistent response, in conjunction with high variability in SI, indicates that reconstructions of absolute palaeo-[CO2] based at the genus level, or upon multiple species for discrete intervals of time are not as reliable as those based on a single or multiple temporally overlapping species.
Collapse
Affiliation(s)
- Matthew Haworth
- School of Biology & Environmental Science, University College Dublin, Belfield, Dublin 4, Ireland.
| | | | | |
Collapse
|
24
|
Miller-Rushing AJ, Primack RB, Templer PH, Rathbone S, Mukunda S. Long-term relationships among atmospheric CO2, stomata, and intrinsic water use efficiency in individual trees. AMERICAN JOURNAL OF BOTANY 2009; 96:1779-86. [PMID: 21622298 DOI: 10.3732/ajb.0800410] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Leaf-level responses to increases in atmospheric carbon dioxide (CO(2)) concentrations could have large implications for water and carbon cycles. We investigated whether stomatal density, guard cell length, and intrinsic water use efficiency (iWUE) of 27 individual trees growing at the Arnold Arboretum in Boston, Massachusetts have responded to changing environmental conditions over the last 100 years. We examined leaves from 74 herbarium specimens collected from three genera-Acer (maples), Quercus (oaks), and Carpinus (hornbeams)-from 1893 to 2006. During this period, global average atmospheric CO(2) concentrations increased by approximately 29% (86 ppm), and temperatures in Boston increased by 1.8°C. Stomatal density and guard cell length were negatively correlated in oaks and hornbeams. Although stomatal density declined and guard cell length increased over time, the changes were not dependent on the magnitude of changes in CO(2) concentrations. Intrinsic WUE did not change significantly over time. Our findings suggest that iWUE may not respond to changes in CO(2) concentrations over the lifetimes of individual trees, possibly because of compensating changes in stomatal density and guard cell size. We provide an example of a method that can enable researchers to differentiate between genetic and plastic responses to global change in long-lived trees.
Collapse
|
25
|
Abstract
Complementary to measurements in Antarctic ice cores, stomatal frequency analysis of leaves of land plants preserved in peat and lake deposits can provide a proxy record of preindustrial atmospheric CO(2) concentration. CO(2) trends based on leaf remains of Quercus robur (English oak) from the Netherlands support the presence of significant CO(2) variability during the first half of the last millennium. The amplitude of the reconstructed multidecadal fluctuations, up to 34 parts per million by volume, considerably exceeds maximum shifts measured in Antarctic ice. Inferred changes in CO(2) radiative forcing are of a magnitude similar to variations ascribed to other mechanisms, particularly solar irradiance and volcanic activity, and may therefore call into question the concept of the Intergovernmental Panel on Climate Change, which assumes an insignificant role of CO(2) as a preindustrial climate-forcing factor. The stomata-based CO(2) trends correlate with coeval sea-surface temperature trends in the North Atlantic Ocean, suggesting the possibility of an oceanic source/sink mechanism for the recorded CO(2) changes.
Collapse
|
26
|
Konrad W, Roth-Nebelsick A, Grein M. Modelling of stomatal density response to atmospheric. J Theor Biol 2008; 253:638-58. [DOI: 10.1016/j.jtbi.2008.03.032] [Citation(s) in RCA: 117] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2007] [Revised: 03/11/2008] [Accepted: 03/27/2008] [Indexed: 11/17/2022]
|
27
|
Kirschbaum MUF. Direct and indirect climate change effects on photosynthesis and transpiration. PLANT BIOLOGY (STUTTGART, GERMANY) 2004; 6:242-253. [PMID: 15143433 DOI: 10.1055/s-2004-820883] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Climate change affects plants in many different ways. Increasing CO(2) concentration can increase photosynthetic rates. This is especially pronounced for C(3) plants, at high temperatures and under water-limited conditions. Increasing temperature also affects photosynthesis, but plants have a considerable ability to adapt to their growth conditions and can function even at extremely high temperatures, provided adequate water is available. Temperature optima differ between species and growth conditions, and are higher in elevated atmospheric CO(2). With increasing temperature, vapour pressure deficits of the air may increase, with a concomitant increase in the transpiration rate from plant canopies. However, if stomata close in response to increasing CO(2) concentration, or if there is a reduction in the diurnal temperature range, then transpiration rates may even decrease. Soil organic matter decomposition rates are likely to be stimulated by higher temperatures, so that nutrients can be more readily mineralised and made available to plants. This is likely to increase photosynthetic carbon gain in nutrient-limited systems. All the factors listed above interact strongly so that, for different combinations of increases in temperature and CO(2) concentration, and for systems in different climatic regions and primarily affected by water or nutrient limitations, photosynthesis must be expected to respond differently to the same climatic changes.
Collapse
Affiliation(s)
- M U F Kirschbaum
- CSIRO Forestry and Forest Products, P.O. Box 4008, Kingston ACT 2604, Australia.
| |
Collapse
|