External heat-pulse method allows comparative sapflow measurements in diverse functional types in a Mediterranean-type shrubland in South Africa
Robert P. Skelton A C , Adam G. West A , Todd E. Dawson B and Jenny M. Leonard A
+ Author Affiliations
- Author Affiliations
A University of Cape Town – Botany, HW Pearson Building Upper Campus, Cape Town, Western Cape 7700, South Africa.
B University of California Berkeley – Dept of Integrative Biology, 3060 Valley Life Sciences Building, Berkeley, CA 94720, USA.
C Corresponding author. Email: skelrob@gmail.com
Functional Plant Biology 40(10) 1076-1087 https://doi.org/10.1071/FP12379
Submitted: 15 December 2012 Accepted: 23 March 2013 Published: 8 May 2013
Abstract
There has been limited application of sapflow technology to small-stemmed species and across co-existing functional types, restricting its use in diverse floras such as the Mediterranean-type shrubland in South Africa. Our main objective was to test whether sapflow may provide an alternative to traditional gas-exchange measurements, which would permit comparative evaluation of transpiration at a previously unattained temporal resolution. We tested miniature external heat ratio method (HRM) sapflow gauges on three co-occurring functional types with contrasting stem or culm anatomies and examined the relationship between sapflow and shoot- and leaf-level water loss in both a controlled and field environment. Our sapflow gauges captured dynamic patterns of transpiration in both settings for all three functional types. In a controlled environment the relationship between sapflow and transpiration was linear in all three species with r2 values ranging from 0.78 for Cannomois congesta Mast. (Restionaceae) to 0.96 for Protea repens (L.) L. (Proteaceae) and Erica monsoniana L.f. (Ericaceae). In the field, r2 values were lower, ranging from 0.59 for C. congesta to 0.74 for P. repens. We discuss the efficacy and potential of this methodology to cast light on patterns of community ecology in functionally diverse shrublands by capturing continuous variation in transpiration.
Additional keywords: cape floristic region, ecophysiology, Ericaceae, fynbos, Proteaceae, Restionaceae, transpiration.
References
Araya YN, Silvertown J, Gowing DJ, McConway KJ, Linder HP, Midgley GF (2011) A fundamental, eco-hydrological basis for niche segregation in plant communities. New Phytologist 189, 253–258.| A fundamental, eco-hydrological basis for niche segregation in plant communities.Crossref | GoogleScholarGoogle Scholar | 20868394PubMed |
Breshears DD, Cobb NS, Rich PM, Price KP, Allen CD, Balice RG, Romme WH, Kastens JH, Floyd ML, Belnap J, Anderson JJ, Myers OB, Meyer CW (2005) Regional vegetation die-off in response to global-change-type drought. Proceedings of the National Academy of Sciences of the United States of America 102, 15 144–15 148.
| Regional vegetation die-off in response to global-change-type drought.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2MXhtFGqtb3I&md5=fcb6453a35b1ec0df634ef54ce87b87dCAS |
Burgess SSO, Adams MA, Bleby TM (2000) Measurement of sap flow in roots of woody plants: a commentary. Tree Physiology 20, 909–913.
| Measurement of sap flow in roots of woody plants: a commentary.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD3MvgvFWnsA%3D%3D&md5=4eb7a752329796d835ea6957f7bdeef4CAS |
Burgess SSO, Adams MA, Turner NC, Beverly CR, Ong CK, Khan AA, Bleby TM (2001) An improved heat pulse method to measure low and reverse rates of sap flow in woody plants. Tree Physiology 21, 589–598.
| An improved heat pulse method to measure low and reverse rates of sap flow in woody plants.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD38%2Fht1Kjsw%3D%3D&md5=0dd686b5e5e09819bd3c7fbc11a6580cCAS |
Clearwater MJ, Luo Z, Mazzeo M, Dichio B (2009) An external heat pulse method for measurement of sap flow through fruit pedicels, leaf petioles and other small-diameter stems. Plant, Cell & Environment 32, 1652–1663.
| An external heat pulse method for measurement of sap flow through fruit pedicels, leaf petioles and other small-diameter stems.Crossref | GoogleScholarGoogle Scholar |
Cleveland WS, Devlin SJ (1988) Locally weighted regression: an approach to regression analysis by local fitting. Journal of the American Statistical Association 83, 596–610.
| Locally weighted regression: an approach to regression analysis by local fitting.Crossref | GoogleScholarGoogle Scholar |
Cohen Y, Fuchs M (1989) Problems in calibrating the heat pulse method for measuring sap flow in the stem of trees and herbaceous plants. Agronomie 9, 321–325.
| Problems in calibrating the heat pulse method for measuring sap flow in the stem of trees and herbaceous plants.Crossref | GoogleScholarGoogle Scholar |
Cohen Y, Li Y (1996) Validating sap flow measurement in field-grown sunflower and corn. Journal of Experimental Botany 47, 1699–1707.
| Validating sap flow measurement in field-grown sunflower and corn.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK2sXjsFGntQ%3D%3D&md5=5c5c273286b23679ea7d9c2ba0a023c6CAS |
Cowling RM, Rundel PW, Lamont BB, Arroyo MK, Arianoutsou M (1996) Plant diversity in mediterranean-climate regions. Trends in Ecology & Evolution 11, 362–366.
| Plant diversity in mediterranean-climate regions.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BC3M7itFGjtg%3D%3D&md5=04037125a761a1804f0f1ddecdab8d78CAS |
Edwards WRN, Becker P, Eermak J (1997) A unified nomenclature for sap flow measurements. Tree Physiology 17, 65–67.
| A unified nomenclature for sap flow measurements.Crossref | GoogleScholarGoogle Scholar |
Ewers BE, Oren R (2000) Analyses of assumptions and errors in the calculation of stomatal conductance from sap flux measurements. Tree Physiology 20, 579–589.
| Analyses of assumptions and errors in the calculation of stomatal conductance from sap flux measurements.Crossref | GoogleScholarGoogle Scholar | 12651422PubMed |
Hoffman MT, Carrick PJ, Gillson L, West AG (2009) Drought, climate change and vegetation response in the succulent karoo, South Africa. South African Journal of Science 105, 54–60.
| Drought, climate change and vegetation response in the succulent karoo, South Africa.Crossref | GoogleScholarGoogle Scholar |
Kume T, Onozawa Y, Komatsu H, Tsuruta K, Shinohara Y, Umebayashi T, Otsuki K (2010) Stand-scale transpiration estimates in a Moso bamboo forest: (I) applicability of sap flux measurements. Forest Ecology and Management 260, 1287–1294.
| Stand-scale transpiration estimates in a Moso bamboo forest: (I) applicability of sap flux measurements.Crossref | GoogleScholarGoogle Scholar |
Linder HP (2003) The radiation of the Cape flora, southern Africa. Biological Reviews of the Cambridge Philosophical Society 78, 597–638.
| The radiation of the Cape flora, southern Africa.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD2c%2FgsVWksg%3D%3D&md5=1d10fcb844c6e706447172ed02796b10CAS | 14700393PubMed |
Lumsden TG, Schulze RE, Hewitson BC (2009) Evaluation of potential changes in hydrologically relevant statistics of rainfall in Southern Africa under conditions of climate change. Water S.A. 35, 649–656.
| Evaluation of potential changes in hydrologically relevant statistics of rainfall in Southern Africa under conditions of climate change.Crossref | GoogleScholarGoogle Scholar |
Madurapperuma WS, Bleby TM, Burgess SSO (2009) Evaluation of sap flow methods to determine water use by cultivated palms. Environmental and Experimental Botany 66, 372–380.
| Evaluation of sap flow methods to determine water use by cultivated palms.Crossref | GoogleScholarGoogle Scholar |
Marloth R (1903) Results of experiments on Table Mountain for ascertaining the amount of moisture deposited from the south east clouds. Transactions of the South African Philosophical Society 14, 403–408.
| Results of experiments on Table Mountain for ascertaining the amount of moisture deposited from the south east clouds.Crossref | GoogleScholarGoogle Scholar |
Marloth R (1905) Results of further experiments on Table Mountain for ascertaining the amount of precipitation deposited from southeast clouds. Transactions of the South African Philosophical Society 16, 97–105.
| Results of further experiments on Table Mountain for ascertaining the amount of precipitation deposited from southeast clouds.Crossref | GoogleScholarGoogle Scholar |
Marshall DC (1958) Measurement of sap flow in conifers by heat transport. Plant Physiology 33, 385–396.
| Measurement of sap flow in conifers by heat transport.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD28zhtleltQ%3D%3D&md5=e7d4848ccd02c6fa1977cb8f62cf6592CAS | 16655154PubMed |
McDowell NG, Pockman WT, Allen CD, Breshears DD, Cobb N, Kolb T, Plaut J, Sperry J, West A, Williams DG, Yepez EA (2008) Mechanisms of plant survival and mortality during drought: why do some plants survive while others succumb to drought? New Phytologist 178, 719–739.
| Mechanisms of plant survival and mortality during drought: why do some plants survive while others succumb to drought?Crossref | GoogleScholarGoogle Scholar |
Midgley GF, Hannah L, Millar D, Rutherford MC, Powrie LW (2002) Assessing the vulnerability of species richness to anthropogenic climate change in a biodiversity hotspot. Global Ecology and Biogeography 11, 445–451.
| Assessing the vulnerability of species richness to anthropogenic climate change in a biodiversity hotspot.Crossref | GoogleScholarGoogle Scholar |
Nagel JF (1956) Fog precipitation on Table Mountain. Quarterly Journal of the Royal Meteorological Society 82, 452–460.
| Fog precipitation on Table Mountain.Crossref | GoogleScholarGoogle Scholar |
Oren R, Sperry JS, Katul GG, Pataki DE, Ewers BE, Phillips N, Schafer KVR (1999) Survey and synthesis of intra- and interspecific variation in stomatal sensitivity to vapour pressure deficit. Plant, Cell & Environment 22, 1515–1526.
| Survey and synthesis of intra- and interspecific variation in stomatal sensitivity to vapour pressure deficit.Crossref | GoogleScholarGoogle Scholar |
R Development Core Team (2011) ‘R: a language and environment for statistical computing.’ (R Foundation for Statistical Computing: Vienna, Austria)
Roddy A, Dawson TE (2012) Determining the water flow dynamics during flowering using miniature sap flow sensors. Acta Horticulturae 951, 47–53.
Vandegehuchte MW, Steppe K (2012a) A triple-probe heat-pulse method for measurement of thermal diffusivity in trees. Agricultural and Forest Meteorology 160, 90–99.
| A triple-probe heat-pulse method for measurement of thermal diffusivity in trees.Crossref | GoogleScholarGoogle Scholar |
Vandegehuchte MW, Steppe K (2012b) Sapflow+: a four-needle heat-pulse sap flow sensor enabling nonempirical sap flux density and water content measurements. New Phytologist 196, 306–317.
| Sapflow+: a four-needle heat-pulse sap flow sensor enabling nonempirical sap flux density and water content measurements.Crossref | GoogleScholarGoogle Scholar | 22816502PubMed |
Wang Q, Fleisher DH, Timlin D, Reddy VR, Chun JA (2012) Quantifying the measurement errors in a portable open gas-exchange system and their effects on the parameterization of Farquhar et al. model for C3 leaves. Photosynthetica 50, 223–238.
| Quantifying the measurement errors in a portable open gas-exchange system and their effects on the parameterization of Farquhar et al. model for C3 leaves.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC38XotlChtrw%3D&md5=00ed8f2f5548a1ac59ba1cc4181fbb76CAS |
West AG, Dawson TE, February EC, Midgley GF, Bond WJ, Aston TL (2012) Diverse functional responses to drought in a Mediterranean-type shrubland in South Africa. New Phytologist 195, 396–407.
| Diverse functional responses to drought in a Mediterranean-type shrubland in South Africa.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BC38njvF2huw%3D%3D&md5=382c43082caad873d01b1844a394e1f7CAS | 22594652PubMed |
Wullschleger SD, Meinzer FC, Vertessy RA (1998) A review of whole-plant water use studies in trees. Tree Physiology 18, 499–512.
| A review of whole-plant water use studies in trees.Crossref | GoogleScholarGoogle Scholar | 12651336PubMed |
Zeppel M, Macinnis-Ng C, Palmer A, Taylor D, Whitley R, Fuentes S, Yunusa I, Williams M, Eamus D (2008) An analysis of the sensitivity of sap flux to soil and plant variables assessed for an Australian woodland using a soil–plant–atmosphere model. Functional Plant Biology 35, 509–520.
| An analysis of the sensitivity of sap flux to soil and plant variables assessed for an Australian woodland using a soil–plant–atmosphere model.Crossref | GoogleScholarGoogle Scholar |
