EVIDENCE TRANSFERS AND BIOGEOGRAPHIC CONTEXT IN THE URBAN MANAGEMENT OF CONOCARPUS ERECTUS: A CRITICAL SYNTHESIS WITH A LAHORE, PAKISTAN, CASE APPLICATION
DOI:
https://doi.org/10.64013/bbasrjlifess.v2026i1.72Keywords:
Conocarpus erectus, urban forestry, evidence transfer, ecosystem disservices, taxonomic resolutionAbstract
Urban-tree controversies often arise when evidence measured at one biological or geographical scale is used to justify management decisions at another. Conocarpus erectus L. provides a useful test case because it is valued for stress tolerance and restoration in parts of its native range, while large introduced plantings have attracted concern over pollen, roots, water use, biodiversity, allelopathy and naturalization. This critical synthesis evaluates that evidence with Lahore, Pakistan, as a case application rather than as the assumed source of all reported species effects. Species-resolved studies are separated from mixed-Conocarpus records, and major claims are appraised for taxonomic resolution, directness of measurement, ecological realism, comparator quality and transferability to Lahore. Thirty-one empirical studies form the species-focused evidence ledger, supported by broader urban-forestry syntheses and Lahore planning sources. Evidence is most consistent for drought and salinity tolerance in young plants, persistence under polluted field conditions, accumulation of several trace metals, and pollen sensitization in susceptible clinical populations. Root–utility conflict is documented but conditional on engineering context. Allelopathic activity is experimentally demonstrated, whereas its magnitude beneath mature urban canopies remains unquantified. No reviewed study measures C. erectus-specific groundwater drawdown in Lahore, and none attributes the city's long-term bird decline to this tree. Recent 2026 studies extend the evidence base in contrasting biogeographic contexts, documenting parasite pressure in introduced Punjab populations while emphasizing propagation and conservation in the native range. For Lahore, the evidence supports taxonomic verification, avoidance of new single-species dependence, retention of low-risk mature canopy during diversification, targeted monitoring of unresolved exposure and water questions, and phased replacement where measured risk is high. The proposed retain–monitor–diversify–replace framework is an evidence-informed adaptive decision aid, not a validated threshold model.
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References
Ahmad, M., Sajjad, H.A., & Naeem-Ullah, U. (2025). Arthropod fauna on Conocarpus plants in urban landscapes. Journal of Agriculture and Biology, 3(2), 231–236. https://doi.org/10.55627/agribiol.003.02.1159
Ajani, A., & Shams, Z.I. (2016). Comparative status of sequestered carbon stock of Azadirachta indica and Conocarpus erectus at the University of Karachi Campus, Pakistan. International Journal of Environment, 5(2), 89–97. https://doi.org/10.3126/ije.v5i2.15009
Alsharekh, A., El-Sheikh, M.A., Alatar, A., & Abdel-Salam, E.M. (2022). Natural control of weed invasions in hyper-arid arable farms: allelopathic potential effect of Conocarpus erectus against common weeds and vegetables. Agronomy, 12, 703. https://doi.org/10.3390/agronomy12030703
Anwar, M.M., Hashim, M., Aziz, A., Stocco, A., Abdo, H.G., Almohamad, H., Al Dughairi, A.A., & Al-Mutiry, M. (2023). Urban green spaces distribution and disparities in congested populated areas: a geographical assessment from Pakistan. Sustainability, 15, 8059. https://doi.org/10.3390/su15108059
Arif, A., Rasheed, F., Hussain, M.S., Ashraf, I., Nawaz, M.F., & Tanvir, M.A. (2022). Acclimatization strategy of two common tree species under water stress. Pakistan Journal of Botany, 54(3), 781–786. https://doi.org/10.30848/PJB2022-3(14)
Asif, M., Saqib, M., Yousaf, B., Adnan, M., Yousaf, A., Ali, A., & Sabir, D. (2014). Growth and ionic composition of buttonwood (Conocarpus erectus L.) in response to soil salinity and water stress. Advances in Life Science and Technology, 19, 42–51.
Azam, A., Iqbal, U., Usman, Z., Sharif, M., Gul, M.F., Naz, N., Nawaz, I., & Ahmad, F. (2025). Biomonitoring and phytoremediation potential of Conocarpus erectus (Buttonwood) for mitigating air pollution from highway traffic. Chemosphere, 375, 144259. https://doi.org/10.1016/j.chemosphere.2025.144259
Berthon, K., Thomas, F., & Bekessy, S. (2021). The role of nativeness in urban greening to support animal biodiversity. Landscape and Urban Planning, 205, 103959. https://doi.org/10.1016/j.landurbplan.2020.103959
Bhatti, U.A., Yu, Z., Hasnain, A., Nawaz, S.A., Yuan, L., Wen, L., & Bhatti, M.A. (2022). Evaluating the impact of roads on the diversity pattern and density of trees to improve the conservation of species. Environmental Science and Pollution Research, 29, 14780–14790. https://doi.org/10.1007/s11356-021-16627-y
Dehdari Rad, H., Assarehzadegan, M.A., Goudarzi, G., Sorooshian, A., Tahmasebi Birgani, Y., Maleki, H., Jahantab, S., Idani, E., Babaei, A.A., & Neisi, A. (2019). Do Conocarpus erectus airborne pollen grains exacerbate autumnal thunderstorm asthma attacks in Ahvaz, Iran? Atmospheric Environment, 213, 311–325. https://doi.org/10.1016/j.atmosenv.2019.06.010
Dehdari Rad, H., Maleki, H., Goudarzi, G., Assarehzadegan, M.A., Idani, I., Babaei, A.A., Neisi, A., Jahantab, S., Parishani, M.R., Dinarvand, M., Sorooshian, A., Namjoyan, F., & Nourmoradi Pour, M. (2023). Investigating airborne pollen grains and fungal spores that might be related to thunderstorm asthma attacks. International Journal of Environmental Research, 17(2), 28. https://doi.org/10.1007/s41742-023-00515-z
de Souza, M.R., Maciel, E.R.F., dos Santos Souza, C., Salami, G., de Holanda, A.C., & Araujo, P.C.D. (2026). Cutting and juvenile cutting as complementary strategies for the propagation and conservation of Conocarpus erectus. Restoration Ecology, 34(3), e70257. https://doi.org/10.1111/rec.70257
El-Mahrouk, E.-S.M., Eldawansy, S.M., El-Tarawy, A.M., Ebrahim, H.M.A., Eisa, E.A., Tilly-Mándy, A., & Honfi, P. (2024). Evaluation of the growth, enzymatic activity, electrolyte leakage, and phytoremediation efficiency of Conocarpus erectus under cadmium and lead stress. Frontiers in Plant Science, 15, 1466697. https://doi.org/10.3389/fpls.2024.1466697
Escobedo, F.J., Kroeger, T., & Wagner, J.E. (2011). Urban forests and pollution mitigation: analyzing ecosystem services and disservices. Environmental Pollution, 159, 2078–2087. https://doi.org/10.1016/j.envpol.2011.01.010
Farid, N., Moazzam, M.F.U., Ahmad, S.R., Coluzzi, R., & Lanfredi, M. (2022). Monitoring the impact of rapid urbanization on land surface temperature and assessment of surface urban heat island using Landsat in megacity (Lahore) of Pakistan. Frontiers in Remote Sensing, 3, 897397. https://doi.org/10.3389/frsen.2022.897397
Fazal, S., Ali, Z., Manzoor, F., & Nazir, A. (2014). A study on the avian (passerine) diversity of Lahore. Journal of Animal and Plant Sciences, 24(4), 1270–1275.
Glèlè Kakaï, F., Salako, K.V., Gnansounou, S.C., Sonounameto, R.C., Zanvo, S.M., Akouété, P.L.E., Houndjinou, E., & Glèlè Kakaï, R. (2026). Conocarpus erectus L., a neglected mangrove species in West Africa: traditional knowledge, its transmission and implications for conservation in Benin. Trees, Forests and People, 27, 101453. https://doi.org/10.1016/j.tfp.2026.101453
Idani, E., Dastoorpoor, M., Goudarzi, G., Haddadzadeh Shoushtari, M., & Raji, H. (2021). Three consecutive episodes of thunderstorm asthma in Ahvaz, Iran: the possible role of Conocarpus pollen. Tanaffos, 20(3), 261–267.
Institute of Forest Genetics and Tree Breeding ENVIS. (2024). Gujarat bans exotic Conocarpus tree amid health and environment hazard: archived environmental information note citing the Gujarat Forest Department circular of 26 September 2023. https://ifgtbenvis.in/news.php?year=2024 (accessed 12 September 2026).
Iqbal, U., Azam, A., Ahmad, K.S., Mumtaz, S., Mehmood, A., Naz, N., Usman, Z., Abbas, H., & Akram, M. (2024). Unveiling the ecological dominance of button mangrove (Conocarpus erectus L.) through microstructural and functional traits modifications across heterogenic environmental conditions. Botanical Studies, 65, 36. https://doi.org/10.1186/s40529-024-00440-0
Irshad, Z., Hassan, M., Akbar, S., Farooq, M., & Chishtie, F.A. (2024). Spatiotemporal changes in LULC and associated impact on urban heat islands over Pakistan using geospatial techniques. Urban Climate, 57, 102112. https://doi.org/10.1016/j.uclim.2024.102112
Keighery, G.J., & Long, V. (2022). The Button Mangrove Conocarpus erectus (Combretaceae) is naturalised in Western Australia. Nuytsia, 33, 29–33. https://doi.org/10.58828/nuy01020
Kendal, D., Dobbs, C., & Lohr, V.I. (2014). Global patterns of diversity in the urban forest: Is there evidence to support the 10/20/30 rule? Urban Forestry & Urban Greening, 13, 411–417. https://doi.org/10.1016/j.ufug.2014.04.004
Livesley, S.J., McPherson, E.G., & Calfapietra, C. (2016). The urban forest and ecosystem services: impacts on urban water, heat, and pollution cycles at the tree, street, and city scale. Journal of Environmental Quality, 45, 119–124. https://doi.org/10.2134/jeq2015.11.0567
Mokal, M.N., Rashid, M., Perveen, A., Hassan, N.U., Kareem, N., & Ilyas, A. (2025). Phytochemical profiling and allelopathic impact of Conocarpus erectus L. on selected agricultural crops. Journal Plantarum, 7(1), 105–118. https://doi.org/10.46662/plantarum.v7i1.127
Nasar-U-Minallah, M., Haase, D., & Qureshi, S. (2024). Evaluating the impact of landscape configuration, patterns and composition on land surface temperature: an urban heat island study in the megacity Lahore, Pakistan. Environmental Monitoring and Assessment, 196, 627. https://doi.org/10.1007/s10661-024-12758-0
Paquette, A., Sousa-Silva, R., Maure, F., Cameron, E.R., Belluau, M., & Messier, C. (2021). Praise for diversity: a functional approach to reduce risks in urban forests. Urban Forestry & Urban Greening, 62, 127157. https://doi.org/10.1016/j.ufug.2021.127157
Rahman, S.U., Yasin, G., Nawaz, M.F., Cheng, H., Azhar, M.F., Riaz, L., Javed, A., & Lu, Y. (2022). Evaluation of heavy metal phytoremediation potential of six tree species of Faisalabad city of Pakistan during summer and winter seasons. Journal of Environmental Management, 320, 115801. https://doi.org/10.1016/j.jenvman.2022.115801
Ramezani, Z., Mousavi, H., Zamani, M., Ghaderi, F., Tahmasebi, R., Movahed, A., Goreh, A., Keshmiri, S., Darabi, A., & Farrokhi, S. (2022). Reactivity to Conocarpus tree pollen in patients with respiratory allergic diseases in the south-western part of Iran. Grana, 61(2), 140–147. https://doi.org/10.1080/00173134.2021.1995782
Randrup, T.B., McPherson, E.G., & Costello, L.R. (2003). A review of tree root conflicts with sidewalks, curbs, and roads. Urban Ecosystems, 5, 209–225.
Rani, W., Ahmad, F., Shahbaz, M., & Younis, A. (2026). Effect of Cuscuta infestation on growth, physiological and biochemical attributes of Conocarpus erectus L. from diverse habitats. Pakistan Journal of Botany, 58(7), 1507–1522. https://doi.org/10.30848/PJB2026-7(12)
Rasheed, F., Gondal, A., Abdul Kudus, K., Zafar, Z., Nawaz, M.F., Khan, W.R., Abdullah, M., Ibrahim, F.H., Depardieu, C., Pazi, A.M.M., Anjum, K., Afzal, S., Akram, S., & Nazre, M. (2021). Effects of soil water deficit on three tree species of the arid environment: variations in growth, physiology, and antioxidant enzyme activities. Sustainability, 13, 3336. https://doi.org/10.3390/su13063336
Rastmanesh, F., Farrash-Alvar, S., & Shalbaf, F. (2024). Concentration of heavy metals in soil and leaves of Conocarpus erectus tree: a biomonitoring study, Ahvaz, Iran. Environmental Monitoring and Assessment, 196, 579. https://doi.org/10.1007/s10661-024-12728-6
Rehman, A.U., Yasmeen, K., Islam, F., Anees, S.A., Tariq, A., Zubair, M., Bilal, M., Rahman, I.U., Rahman, S.U., & Hatamleh, W.A. (2023). Assessment of heavy metal accumulation in dust and leaves of Conocarpus erectus in urban areas: implications for phytoremediation. Physics and Chemistry of the Earth, 132, 103481. https://doi.org/10.1016/j.pce.2023.103481
Rehman, S., Abbas, G., Shahid, M., Saqib, M., Farooq, A.B.U., Hussain, M., Murtaza, B., Amjad, M., Naeem, M.A., & Farooq, A. (2019). Effect of salinity on cadmium tolerance, ionic homeostasis and oxidative stress responses in Conocarpus exposed to cadmium stress: implications for phytoremediation. Ecotoxicology and Environmental Safety, 171, 146–153. https://doi.org/10.1016/j.ecoenv.2018.12.077
Rehman, S.U., Aslam, Z., Aljuaid, B.S., Abbas, R.N., Bashir, S., Almas, M.H., Awan, T.H., Belliturk, K., Al-Taisan, W.A., Mahmoud, S.F., & Bashir, S. (2022). Reduction in the allelopathic potential of Conocarpus erectus L. through vermicomposting. Sustainability, 14, 12840. https://doi.org/10.3390/su141912840
Roman, L.A., Conway, T.M., Eisenman, T.S., Koeser, A.K., Ordóñez Barona, C., Locke, D.H., Jenerette, G.D., Östberg, J., & Vogt, J. (2021). Beyond “trees are good”: disservices, management costs, and tradeoffs in urban forestry. Ambio, 50, 615–630. https://doi.org/10.1007/s13280-020-01396-8
Roy, S., Byrne, J., & Pickering, C. (2012). A systematic quantitative review of urban tree benefits, costs, and assessment methods across cities in different climatic zones. Urban Forestry & Urban Greening, 11, 351–363. https://doi.org/10.1016/j.ufug.2012.06.006
Royal Botanic Gardens, Kew. (2026). Plants of the World Online: Conocarpus erectus L. and Conocarpus lancifolius Engl. Royal Botanic Gardens, Kew. https://powo.science.kew.org (accessed 11 September 2026).
Rubab, S., Yaqoob, M.A., Rizwani, G.H., Waleed, M., & Abu Bakar, M. (2026). Ecological benefits and adverse impacts of Conocarpus erectus L.: a review of its invasiveness, adaptability, and environmental implications. Journal of Chemistry and Material Sciences, 3(1), 38–49. https://doi.org/10.71120/j.chem.mater.sci.v3i1.4897
Salmond, J.A., Tadaki, M., Vardoulakis, S., Arbuthnott, K., Coutts, A., Demuzere, M., Dirks, K.N., Heaviside, C., Lim, S., Macintyre, H., McInnes, R.N., & Wheeler, B.W. (2016). Health and climate related ecosystem services provided by street trees in the urban environment. Environmental Health, 15(Suppl 1), 36. https://doi.org/10.1186/s12940-016-0103-6
Schlaepfer, M.A., Guinaudeau, B.P., Martin, P., & Wyler, N. (2020). Quantifying the contributions of native and non-native trees to a city’s biodiversity and ecosystem services. Urban Forestry & Urban Greening, 56, 126861. https://doi.org/10.1016/j.ufug.2020.126861
Shams, Z.I. (2016). Changes in diversity and composition of flora along a corridor of different land uses in Karachi over 20 years: causes and implications. Urban Forestry & Urban Greening, 17, 71–79. https://doi.org/10.1016/j.ufug.2016.03.002
Shams, Z.I., Shahid, M., Nadeem, Z., Naz, S., Raheel, D., Aftab, D., Fraz, T.R., & Roomi, M.S. (2020). Town socio-economic status and road width determine street tree density and diversity in Karachi, Pakistan. Urban Forestry & Urban Greening, 47, 126473. https://doi.org/10.1016/j.ufug.2019.126473
Shamukh, A.F., Ghailan, S.A., & Mohsen, D.M. (2020). Effect of Conocarpus erectus on the infrastructure of Misan Province, Iraq. Plant Archives, 20(Suppl. 2), 1224–1227.
Shi, F., Meng, Q., Pan, L., & Wang, J. (2023). Root damage of street trees in urban environments: an overview of its hazards, causes, and prevention and control measures. Science of the Total Environment, 904, 166728. https://doi.org/10.1016/j.scitotenv.2023.166728
Shoaib, A., & Islam, H.S. (2024). Urban sustainability and green spaces: a comprehensive analysis of spatiotemporal variations and residents’ perspective in Lahore, Pakistan. Journal of Geovisualization and Spatial Analysis, 8, 28. https://doi.org/10.1007/s41651-024-00190-4
Tartaglia, E.S., & Aronson, M.F.J. (2024). Plant native: comparing biodiversity benefits, ecosystem services provisioning, and plant performance of native and non-native plants in urban horticulture. Urban Ecosystems, 27, 2587–2611. https://doi.org/10.1007/s11252-024-01610-5
Tauqeer, H.M., ur-Rahman, M., Hussain, S., Abbas, F., & Iqbal, M. (2019). The potential of an energy crop "Conocarpus erectus" for lead phytoextraction and phytostabilization of chromium, nickel, and cadmium: an excellent option for the management of multi-metal contaminated soils. Ecotoxicology and Environmental Safety, 173, 273–284. https://doi.org/10.1016/j.ecoenv.2019.01.119
Thallapally, S., Chepyala, S., Bathula, J., Mudalkar, S., Eetela, S., & Bodiga, S. (2026). Dose-dependent effects of Conocarpus erectus biochar on the physicochemical and fertility properties of industrial acidic soil. Discover Soil, 3(1), 57. https://doi.org/10.1007/s44378-026-00216-x
Thaweepworadej, P., & Evans, K.L. (2022). Species richness and ecosystem services of tree assemblages along an urbanisation gradient in a tropical mega-city: consequences for urban design. Urban Forestry & Urban Greening, 70, 127527. https://doi.org/10.1016/j.ufug.2022.127527
The Urban Unit. (2025). Lahore City Biodiversity Action Plan. Environment, Biodiversity and Climate Change Division, Planning & Development Board, Government of the Punjab, Lahore. https://urbanunit.gov.pk/Download/publications/Files/27/2025/Lahore_CBAP_KA18082025.pdf (accessed 12 September 2026).
Umer, S., & Hussain, M. (2023). Adaptation of ornamental species for phytoremediation to minimize lead pollution in urban areas. International Journal of Environmental Science and Technology, 20, 12559–12568. https://doi.org/10.1007/s13762-023-04855-3
Umer, S., Abbas, Z., Aziz, I., Hanif, M., Abideen, Z., Mansoor, S., Hamid, N., Ali, M.A., & Al-Hemaid, F.M. (2023). Potential of ornamental trees to remediate trace metal contaminated soils for environmental safety and urban green space development. Sustainability, 15, 8963. https://doi.org/10.3390/su15118963
Zafar, Z., Rasheed, F., Abdullah, M., Salam, M.M.A., & Mohsin, M. (2019). Effects of water deficit on growth and physiology of young Conocarpus erectus L. and Ficus benjamina L. saplings. Bangladesh Journal of Botany, 48(4), 1215–1221. https://doi.org/10.3329/bjb.v48i4.49078
Zafar, Z., Rasheed, F., Ul Haq, A., Ibrahim, F.H., Afzal, S., Nazre, M., Akram, S., Hussain, Z., Abdul Kudus, K., Mohsin, M., Qadeer, A., Raza, Z., & Khan, W.R. (2021a). Interspecific differences in physiological and biochemical traits drive the water stress tolerance in young Morus alba L. and Conocarpus erectus L. saplings. Plants, 10, 1615. https://doi.org/10.3390/plants10081615
Zafar, Z., Rasheed, F., Atif, R.M., Javed, M., Maqsood, M., & Gailing, O. (2021b). Foliar application of salicylic acid improves water stress tolerance in Conocarpus erectus L. and Populus deltoides L. saplings: evidence from morphological, physiological, and biochemical changes. Plants, 10, 1242. https://doi.org/10.3390/plants10061242
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Copyright (c) 2026 M HAMMAD, SHUH SHERAZI, J AHMAD, M SAEED, MB MUSTAFA, MM JAMEEL, M SHAFIQ, HU RASHEED, S KHAN, A ABBAS, AU REHMAN (Author)
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