Carexplanostachys Kunze (Cyperaceae, Cedar sedge) is an herbaceous species in a genus commonly inhabiting mesic or hydric habitats. Carexplanostachys is found in arid and semi-arid Juniperus woodlands. Arid conditions impose survival challenges to plants in dry areas. Some plants have plasticity responses to soil water content and continued normal though reduced functions through droughts, but most herbaceous plants do not survive. Limited previous studies have suggested C. planostachys is tolerant of drought. Physiological responses of C. planostachys from Juniperus woodlands was examined is this study to determine how long plants could survive without water and if they are capable of recovery from very negative water potentials beyond what is considered the permanent wilting point for most herbaceous plants. Plants were placed in pots in partial shade in this experiment. Water loss from the soil with plants was an inverse 2nd order polynomial function with soil water decreasing from 32% to 8% by day 28 of the study. Leaf water potential was also an inverse 2nd order polynomial function but did not decline significantly until 14 days without watering. Leaf water potential was ？10.0 MPa after 35 days without watering. Non-watered plants Anet, (photosynthetic rate) was significantly lower compared to the water treatment by day 21 as was stomatal conductance and transpiration. When non-watered plants were watered after 21, 28 or 35 days, full recovery of physiological responses occurred within 7 days. The length of time that C. planostachys was able to withstand drought was greater than the annual trends in lack of precipitation during springtime in this area. Carexplanostachys can photosynthesize at water stress between ？8 and ？10 MPa. Carexplanostachys drought and shade tolerance enables it to occupy an understory niche devoid of other herbaceous plants.
References
[1]
Little, E.L. (1971) Atlas of United States Trees. Volume 1, Conifers and Important Hardwoods. United States Department of Agriculture. https://doi.org/10.5962/bhl.title.130546
[2]
Correll, D.S. and Johnston, M.C. (1979) Manual of the Vascular Plants of Texas. Texas Research Foundation.
[3]
Van Auken, O.W., Bush, J.K., Taylor, D.L. and Singhurst, J.R. (2023) Lack of Woody Species Recruitment in Isolated Deep Canyon Deciduous Woodlands in Central Texas, USA. The Journal of the Torrey Botanical Society, 150, 525-537. https://doi.org/10.3159/torrey-d-23-00009.1
[4]
House, J.I., Archer, S., Breshears, D.D. and Scholes, R.J. (2003) Conundrums in Mixed Woody-Herbaceous Plant Systems. Journal of Biogeography, 30, 1763-1777. https://doi.org/10.1046/j.1365-2699.2003.00873.x
[5]
Breshears, D.D. (2006) The Grassland-Forest Continuum: Trends in Ecosystem Properties for Woody Plant Mosaics? Frontiers in Ecology and the Environment, 4, 96-104. https://doi.org/10.1890/1540-9295(2006)004[0096:tgctie]2.0.co;2
[6]
Norris, M.D., Blair, J.M., Johnson, L.C. and McKane, R.B. (2001) Assessing Changes in Biomass, Productivity, and C and N Stores Following Juniperus virginiana Forest Expansion into Tallgrass Prairie. Canadian Journal of Forest Research, 31, 1940-1946. https://doi.org/10.1139/x01-132
[7]
Briggs, J.M., Hoch, G.A. and Johnson, L.C. (2002) Assessing the Rate, Mechanisms, and Consequences of the Conversion of Tallgrass Prairie to Juniperus virginiana Forest. Ecosystems, 5, 578-586. https://doi.org/10.1007/s10021-002-0187-4
[8]
Van Auken, O.W. and Smeins, F.E. (2008) Western North American Juniperus Communities: Patterns and Causes of Distribution and Abundance. In: Van Auken, O.W., Ed., Western North American Juniperus Communities: A Dynamic Vegetation Type, Springer, 3-18.
[9]
McPherson, G.R., Wright, H.A. and Wester, D.B. (1988) Patterns of Shrub Invasion in Semiarid Texas Grasslands. American Midland Naturalist, 120, 391-397. https://doi.org/10.2307/2426011
[10]
McPherson, G.R. and Wright, H.A. (1990) Establishment of Juniperus pinchotii in Western Texas: Environmental Effects. Journal of Arid Environments, 19, 283-287. https://doi.org/10.1016/s0140-1963(18)30792-4
[11]
McPherson, G.R. (1997) Ecology and Management of North American Savannas. University of Arizona Press. https://doi.org/10.1353/book.109739
[12]
Baldocchi, D.D. and Wilson, K.B. (2001) Modeling CO2 and Water Vapor Exchange of a Temperate Broadleaved Forest across Hourly to Decadal Time Scales. Ecological Modelling, 142, 155-184. https://doi.org/10.1016/s0304-3800(01)00287-3
[13]
Wayne, E.R. and Van Auken, O.W. (2004) Spatial and Temporal Abiotic Changes along a Canopy to Intercanopy Gradient in Central Texas Juniperus ashei Woodlands. Texas Journal of Science, 56, 35-54.
[14]
McDowell, N., Pockman, W.T., Allen, C.D., Breshears, D.D., Cobb, N., Kolb, T., et al. (2008) Mechanisms of Plant Survival and Mortality during Drought: Why Do Some Plants Survive While Others Succumb to Drought? New Phytologist, 178, 719-739. https://doi.org/10.1111/j.1469-8137.2008.02436.x
Van Auken, O.W., Ford, A.L. and Allen, J.L. (1981) An Ecological Comparison of Upland Deciduous and Evergreen Forests of Central Texas. American Journal of Botany, 68, 1249-1256. https://doi.org/10.1002/j.1537-2197.1981.tb07832.x
[17]
Terletsky, P.A. and Van Auken, O.W. (1996) Comparison of Cedar Glades and Associated Woodlands of the Southern Edwards Plateau. Texas Journal of Science, 48, 55-67.
[18]
Van Auken, O.W. (2000) Shrub Invasions of North American Semiarid Grasslands. Annual Review of Ecology and Systematics, 31, 197-215. https://doi.org/10.1146/annurev.ecolsys.31.1.197
[19]
Wayne, R. and Van Auken, O.W. (2008) Comparison of the Understory Vegetation of Juniperus Woodlands. In: Van Auken, O.W., Ed., Ecology and Management of Western North American Juniperus Communities: A Dynamic Vegetation Type, Ecological Studies, Vol. 196, Springer, 93-110. https://doi.org/10.1007/978-0-387-34003-6_5
[20]
Van Auken, O.W. and McKinley, D.C. (2008) Structure and Composition of Juniperus Communities and Factors That Control Them. In: Van Auken, O.W., Ed., Western North American Juniperus Communities: A Dynamic Vegetation Type, Springer, 19-47. https://doi.org/10.1007/978-0-387-34003-6_2
[21]
Furuya, M. and Van Auken, O.W. (2010) Gas Exchange Rates of Three Sub-Shrubs of Central Texas Savannas. Madroño, 57, 170-179. https://doi.org/10.3120/0024-9637-57.3.170
[22]
Elliott, L.F., Diamond, D.D., True, C.D., Blodgett, C.F., Pursell, D., German, D. and Treuer-Kuehn, A. (2014) Ecological Mapping Systems of Texas: Summary Report. Texas Parks and Wildlife Department.
[23]
Van Auken, O.W. (2018) Ecology of Plant Communities of South-Central Texas. Scientific Research Publishing.
[24]
Wayne, E.R. and Van Auken, O.W. (2009) Light Responses of Carexplanostachys from Various Microsites in a Juniperus Community. Journal of Arid Environments, 73, 435-443. https://doi.org/10.1016/j.jaridenv.2008.12.006
[25]
McDowell, N., Pockman, W.T., Allen, C.D., Breshears, D.D., Cobb, N., Kolb, T., et al. (2008) Mechanisms of Plant Survival and Mortality during Drought: Why Do Some Plants Survive While Others Succumb to Drought? New Phytologist, 178, 719-739. https://doi.org/10.1111/j.1469-8137.2008.02436.x
[26]
Taiz, L. Moller, I.M., Murphy, A. and Zeiger, E. (2023) Plant Physiology and Development. Seventh Edition, Sinauer Associates, 752.
[27]
Ball, P.W. (1990) Some Aspects of the Phytogeography of Carex. Canadian Journal of Botany, 68, 1462-1472. https://doi.org/10.1139/b90-185
[28]
Busch, J. (2001) Characteristic Values of Key Ecophysiological Parameters in the Genus Carex. Flora, 196, 405-430. https://doi.org/10.1016/s0367-2530(17)30084-1
[29]
Wayne, E.R. and Van Auken, O.W. (2018) Photosynthetic Comparison of Carexplanostachys (C3) and Aristida purpurea (C4) to Light and Water Manipulations. Phytologia, 100, 91-103.
[30]
Begon, M., Townsend, C.R. and Harper, J.L. (2006) Ecology: From Individuals to Ecosystems. Blackwell Publishing.
[31]
Wayne, E.R. (2007) Factors Controlling the Distribution of an Understory Sedge in Juniperus Woodlands. Ph.D. Dissertation, The University of Texas at San Antonio.
[32]
Givnish, T.J., Montgomery, R.A. and Goldstein, G. (2004) Adaptive Radiation of Photosynthetic Physiology in the Hawaiian Lobeliads: Light Regimes, Static Light Responses, and Whole‐Plant Compensation Points. American Journal of Botany, 91, 228-246. https://doi.org/10.3732/ajb.91.2.228
[33]
SAS (2005) SAS/STAT 9.1 User’s Guide SAS Publishing.
[34]
Littell, R.C., Milliken, G.A., Stroup, W.W., Wolfinger, R.D. and Schabenberger, O. (2006) SAS for Mixed Models. Second Edition, SAS Institute Inc.
[35]
Fitzmaurice, G.M., Laird, N.M. and Ware, J.H. (2004) Applied Longitudinal Analysis. John Wiley & Sons, Inc.
[36]
Hull, J.C. (2002) Photosynthetic Induction Dynamics to Sunflecks of Four Deciduous Forest Understory Herbs with Different Phenologies. International Journal of Plant Sciences, 163, 913-924. https://doi.org/10.1086/342633
[37]
Bond, B.J., Farnsworth, B.T., Coulombe, R.A. and Winner, W.E. (1999) Foliage Physiology and Biochemistry in Response to Light Gradients in Conifers with Varying Shade Tolerance. Oecologia, 120, 183-192. https://doi.org/10.1007/s004420050847
[38]
Peek, M.S., Russek-Cohen, E., Wait, A.D. and Forseth, I.N. (2002) Physiological Response Curve Analysis Using Nonlinear Mixed Models. Oecologia, 132, 175-180. https://doi.org/10.1007/s00442-002-0954-0
[39]
Van Auken, O.W. (2008) Western North American Juniperus Communities: A Dynamic Vegetation Type. Springer.
Cable, D.R. (1977) Seasonal Use of Soil Water by Mature Velvet Mesquite. Journal of Range Management, 30, 4-11. https://doi.org/10.2307/3897324
[42]
Wayne, R. and Auken, O.W.V. (2002) Spatial and Temporal Patterns of Xylem Water Potential in Juniperus ashei Seedlings. The Southwestern Naturalist, 47, 153-161. https://doi.org/10.2307/3672901
[43]
Holbrook, N.M. (2023) Water and Plant Cells. In: Taiz, L., Moller, I.M., Murphy, A. and Zeiger, E., Eds., Plant Physiology and Development, Oxford University Press, 153-168.
[44]
Rodriguez‐Iturbe, I., D’Odorico, P., Porporato, A. and Ridolfi, L. (1999) On the Spatial and Temporal Links between Vegetation, Climate, and Soil Moisture. Water Resources Research, 35, 3709-3722. https://doi.org/10.1029/1999wr900255
[45]
Sperry, J.S., Hacke, U.G., Oren, R. and Comstock, J.P. (2002) Water Deficits and Hydraulic Limits to Leaf Water Supply. Plant, Cell & Environment, 25, 251-263. https://doi.org/10.1046/j.0016-8025.2001.00799.x
[46]
Knapp, A.K., Fahnestock, J.T., Hamburg, S.P., Statland, L.B., Seastedt, T.R. and Schimel, D.S. (1993) Landscape Patterns in Soil‐Plant Water Relations and Primary Production in Tallgrass Prairie. Ecology, 74, 549-560. https://doi.org/10.2307/1939315
[47]
Knapp, A.K., Hamerlynck, E.P. and Owensby, C.E. (1993) Photosynthetic and Water Relations Responses to Elevated CO2 in the C4 Grass Andropogon Gerardii. International Journal of Plant Sciences, 154, 459-466. https://doi.org/10.1086/297129
[48]
Turner, C.L., Kneisler, J.R. and Knapp, A.K. (1995) Comparative Gas Exchange and Nitrogen Responses of the Dominant C4grass Andropogon Gerardii and Five C3 Forbs to Fire and Topographic Position in Tallgrass Prairie during a Wet Year. International Journal of Plant Sciences, 156, 216-226. https://doi.org/10.1086/297243
[49]
Fay, P.A., Carlisle, J.D., Danner, B.T., Lett, M.S., McCarron, J.K., Stewart, C., et al. (2002) Altered Rainfall Patterns, Gas Exchange, and Growth in Grasses and Forbs. International Journal of Plant Sciences, 163, 549-557. https://doi.org/10.1086/339718
[50]
Sperry, J.S., Saliendra, N.Z., Pockman, W.T., Cochard, H., Cruiziat, P., Davis, S.D., et al. (1996) New Evidence for Large Negative Xylem Pressures and Their Measurement by the Pressure Chamber Method. Plant, Cell & Environment, 19, 427-436. https://doi.org/10.1111/j.1365-3040.1996.tb00334.x
[51]
Jackson, R.B., Anderson, L.J. and Pockman, W.T. (2000) Measuring Water Availability and Uptake in Ecosystem Studies. In: Sala, O.E., Jackson, R.B., Mooney, H.A. and Howarth, R., Eds., Methods in Ecosystem Science, Springer, 199-214. https://doi.org/10.1007/978-1-4612-1224-9_14
[52]
Wayne, E.R. (2000) Water Relations of Juniperus ashei Seedlings and Changes in Biotic and Abiotic Factors along an Environmental Gradient on the Edwards Plateau from under a Juniperus Woodland Canopy into an Intercanopy Patch. Division of Life Science, University of Texas at San Antonio, 150.
[53]
Pugnaire, F.I., Haase, P., Incoll, L.D. and Clark, S.C. (1996) Response of the Tussock Grass Stipa tenacissima to Watering in a Semi-Arid Environment. Functional Ecology, 10, 265-274. https://doi.org/10.2307/2389852
[54]
Chaves, M.M., Maroco, J.P. and Pereira, J.S. (2003) Understanding Plant Responses to Drought—From Genes to the Whole Plant. Functional Plant Biology, 30, 239-264. https://doi.org/10.1071/fp02076
[55]
Tuzet, A., Perrier, A. and Leuning, R. (2003) A Coupled Model of Stomatal Conductance, Photosynthesis and Transpiration. Plant, Cell & Environment, 26, 1097-1116. https://doi.org/10.1046/j.1365-3040.2003.01035.x
[56]
Swemmer, A.M., Knapp, A.K. and Smith, M.D. (2006) Growth Responses of Two Dominant C4 Grass Species to Altered Water Availability. International Journal of Plant Sciences, 167, 1001-1010. https://doi.org/10.1086/505611
[57]
Flexas, J. (2002) Drought-Inhibition of Photosynthesis in C3 Plants: Stomatal and Non-Stomatal Limitations Revisited. Annals of Botany, 89, 183-189. https://doi.org/10.1093/aob/mcf027
[58]
Valladares, F. and Niinemets, Ü. (2008) Shade Tolerance, a Key Plant Feature of Complex Nature and Consequences. Annual Review of Ecology, Evolution, and Systematics, 39, 237-257. https://doi.org/10.1146/annurev.ecolsys.39.110707.173506
[59]
Van Auken, O.W. and Bush, J.K. (2009) The Role of Photosynthesis in the Recruitment of Juvenile Quercus gambelii into Mature Q. gambelii Communities. The Journal of the Torrey Botanical Society, 136, 465-478. https://doi.org/10.3159/09-ra-035.1
[60]
Wayne, E.R. and Van Auken, O.W. (2012) Comparisons of Gas Exchange of Several Sedges and C4 Grasses in Associated Savanna Communities. Phytologia, 94, 71-90.
[61]
Grunstra, M.B. and Van Auken, O.W. (2015) Photosynthetic Characteristics of Garrya ovata Benth. (Lindheimer’s Silktassle, Garryaceae) at Ambient and Elevated Levels of Light, CO2 and Temperature. Phytologia, 97, 103-119.
[62]
Grunstra, M.B. and Van Auken, O.W. (2023) Comparative Gas Exchange of Ulmus crassifolia (Cedar Elm, Ulmaceae) and Ungnadia speciosa (Mexican Buckey, Sapindaceae) at Ambient and Elevated Levels of Light, CO2 and Temperature. American Journal of Plant Sciences, 14, 691-709. https://doi.org/10.4236/ajps.2023.146047
[63]
Muraoka, H., Tang, Y., Koizumi, H. and Washitani, I. (1997) Combined Effects of Light and Water Availability on Photosynthesis and Growth of Arisaema heterophyllum in the Forest Understory and an Open Site. Oecologia, 112, 26-34. https://doi.org/10.1007/s004420050279
[64]
Pearcy, R.W. (2000) Acclimation to Sun and Shade. In: Raghavendra, A.S., Ed., Pho-tosynthesis: A Comprehensive Treatise, Cambridge University Press, 250-263.
[65]
Medrano, H. (2002) Regulation of Photosynthesis of C3 Plants in Response to Progressive Drought: Stomatal Conductance as a Reference Parameter. Annals of Botany, 89, 895-905. https://doi.org/10.1093/aob/mcf079
[66]
Wingler, A., Lea, P.J., Quick, W.P. and Leegood, R.C. (2000) Photorespiration: Metabolic Pathways and Their Role in Stress Protection. Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences, 355, 1517-1529. https://doi.org/10.1098/rstb.2000.0712
[67]
Lawlor, D.W. (2002) Limitation to Photosynthesis in Water-Stressed Leaves: Stomata vs. Metabolism and the Role of ATP. Annals of Botany, 89, 871-885. https://doi.org/10.1093/aob/mcf110
[68]
Comstock, J.P. (2002) Hydraulic and Chemical Signalling in the Control of Stomatal Conductance and Transpiration. Journal of Experimental Botany, 53, 195-200. https://doi.org/10.1093/jexbot/53.367.195
[69]
BassiriRad, H., Tremmel, D.C., Virginia, R.A., Reynolds, J.F., de Soyza, A.G. and Brunell, M.H. (1999) Short-Term Patterns in Water and Nitrogen Acquisition by Two Desert Shrubs Following a Simulated Summer Rain. Plant Ecology, 145, 27-36. https://doi.org/10.1023/a:1009819516976
