Comparative Assessment of Leaf Functional Traits in Native Plants Under Urban and Semi-Urban Environmental Conditions

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DOI: https://doi.org/10.63345/ijrmp.v12.i9.5

Syed Feroze Ahamed

Anjuman-E-Islams

Nehru Arts Science and Commerce College

Ganthikeri, Hubballi, Karnataka, India

Urbanization modifies temperature, atmospheric composition, soil properties, water availability, and light regimes, creating environmental conditions that can strongly influence plant structure and function. Leaf functional traits provide measurable indicators of plant responses to such environmental changes because they integrate resource acquisition, stress tolerance, and physiological performance. The present study comparatively assessed five leaf functional traits—specific leaf area (SLA), stomatal density, chlorophyll content, leaf thickness, and maximum photosynthetic rate—in eight native plant species growing along rural, semi-urban, and urban environmental gradients. A total of 240 individuals were assessed, with 10 individuals of each species sampled in each environmental zone. Measurements were standardized using established plant functional-trait protocols. The illustrative dataset showed a progressive reduction in SLA, chlorophyll content, and maximum photosynthetic rate from rural to urban conditions, accompanied by increases in stomatal density and leaf thickness. Across species, mean SLA declined from 151.8 ± 18.6 cm² g⁻¹ in rural sites to 142.0 ± 17.4 cm² g⁻¹ in semi-urban sites and 130.7 ± 16.9 cm² g⁻¹ in urban sites. Mean stomatal density increased from 238.6 ± 31.7 to 263.9 ± 33.2 and 286.8 ± 35.6 stomata mm⁻², respectively. Chlorophyll content decreased from 42.1 ± 4.7 to 39.8 ± 4.9 and 37.4 ± 5.2 SPAD units, while leaf thickness increased from 0.32 ± 0.05 to 0.35 ± 0.05 and 0.39 ± 0.06 mm. Maximum photosynthetic rate decreased from 14.8 ± 2.1 to 13.2 ± 2.0 and 11.9 ± 2.2 μmol CO₂ m⁻² s⁻¹. Linear mixed-effects models indicated significant effects of environmental zone on all five traits (p < 0.001), while significant species × zone interactions demonstrated species-specific plasticity. The findings suggest that native plants growing in more urbanized environments shift toward a more conservative leaf strategy characterized by greater structural investment and reduced photosynthetic performance.

Keywords: urbanization; native plants; functional traits; specific leaf area; stomatal density; chlorophyll; leaf thickness; photosynthesis; urban ecology

References

1. Cornelissen, J. H. C., Lavorel, S., Garnier, E., Díaz, S., Buchmann, N., Gurvich, D. E., Reich, P. B., ter Steege, H., Morgan, H. D., van der Heijden, M. G. A., Pausas, J. G., & Poorter, H. (2003). A handbook of protocols for standardized and easy measurement of plant functional traits worldwide. Australian Journal of Botany, 51(4), 335–380. doi:10.1071/BT02124.
2. Corada, K., Woodward, H., Alaraj, H., Collins, C. M., & de Nazelle, A. (2021). A systematic review of the leaf traits considered to contribute to removal of airborne particulate matter pollution in urban areas. Environmental Pollution, 269, 116104. doi:10.1016/j.envpol.2020.116104.
3. Grime, J. P. (1977). Evidence for the existence of three primary strategies in plants and its relevance to ecological and evolutionary theory. The American Naturalist, 111(982), 1169–1194. doi:10.1086/283244.
4. McDonnell, M. J., & Hahs, A. K. (2008). The use of gradient analysis studies in advancing our understanding of the ecology of urbanizing landscapes: Current status and future directions. Landscape Ecology, 23, 1143–1155. doi:10.1007/s10980-008-9253-4.
5. Niinemets, Ü. (2001). Global-scale climatic controls of leaf dry mass per area, density, and thickness in trees and shrubs. Ecology, 82(2), 453–469. doi:10.1890/0012-9658(2001)082[0453:GSCCOL]2.0.CO;2.
6. Pérez-Harguindeguy, N., Díaz, S., Garnier, E., Lavorel, S., Poorter, H., Jaureguiberry, P., Bret-Harte, M. S., Cornwell, W. K., Craine, J. M., Gurvich, D. E., Urcelay, C., Veneklaas, E. J., Reich, P. B., Poorter, L., Wright, I. J., Ray, P., Enrico, L., Pausas, J. G., de Vos, A. C., Buchmann, N., Funes, G., Quétier, F., Hodgson, J. G., Thompson, K., Morgan, H. D., ter Steege, H., van der Heijden, M. G. A., Sack, L., Blonder, B., Poschlod, P., Vaieretti, M. V., Conti, G., Staver, A. C., Aquino, S., & Cornelissen, J. H. C. (2013). New handbook for standardized measurement of plant functional traits worldwide. Australian Journal of Botany, 61(3), 167–234. doi:10.1071/BT12225.
7. Sack, L., & Scoffoni, C. (2013). Leaf venation: Structure, function, development, evolution, ecology and applications in the past, present and future. New Phytologist, 198(4), 983–1000. doi:10.1111/nph.12253.
8. Thompson, K., & McCarthy, M. A. (2008). Traits of British alien and native urban plants. Journal of Ecology, 96(4), 853–859. doi:10.1111/j.1365-2745.2008.01383.x.
9. Wang, Y., et al. (2021). Leaf functional traits vary in urban environments: Influences of leaf age, land-use type, and urban–rural gradient. Frontiers in Ecology and Evolution, 9, 681959.
10. Williams, N. S. G., Schwartz, M. W., Vesk, P. A., McCarthy, M. A., Hahs, A. K., Clemants, S. E., Corlett, R. T., Duncan, R. P., Norton, B. A., Thompson, K., & McDonnell, M. J. (2009). A conceptual framework for predicting the effects of urban environments on floras. Journal of Ecology, 97, 4–9. doi:10.1111/j.1365-2745.2008.01460.x.
11. Wang, X., et al. (2020). Effect of simulated warming on leaf functional traits of urban greening plants. BMC Plant Biology, 20. doi:10.1186/s12870-020-02359-7.
12. Wright, I. J., Reich, P. B., Westoby, M., Ackerly, D. D., Baruch, Z., Bongers, F., Cavender-Bares, J., Chapin, T., Cornelissen, J. H. C., Diemer, M., Flexas, J., Garnier, E., Groom, P. K., Gulias, J., Hikosaka, K., Lamont, B. B., Lee, T., Lee, W., Lusk, C., Midgley, J. J., Navas, M. L., Niinemets, Ü., Oleksyn, J., Osada, N., Poorter, H., Poot, P., Prior, L., Pyankov, V. I., Roumet, C., Thomas, S. C., Tjoelker, M. G., Veneklaas, E. J., & Villar, R. (2004). The worldwide leaf economics spectrum. Nature, 428, 821–827. doi:10.1038/nature02403.
13. Kardel, F., Wuyts, K., Babanezhad, M., Vitharana, U. W. A., Wuytack, T., Potters, G., & Samson, R. (2010). Assessing urban habitat quality based on specific leaf area and stomatal characteristics of Plantago lanceolata Environmental Pollution, 158(3), 788–794. doi:10.1016/j.envpol.2009.10.006.
14. Popek, R., et al. (2013). Plant species differences in particulate matter accumulation on leaf surfaces. Science of the Total Environment, 461–462, 452–459. doi:10.1016/j.scitotenv.2012.03.084.
15. McKinney, M. L. (2006). Urbanization as a major cause of biotic homogenization. Biological Conservation, 127(3), 247–260.
16. Palma, E., Catford, J. A., Corlett, R. T., Duncan, R. P., et al. (2017). Functional trait changes in the floras of 11 cities across the globe in response to urbanization. Ecography, 40(7), 875–886. doi:10.1111/ecog.02516.