Seed Morphology and Dispersal Trade-offs in Three Tropical Trees of Semi-Arid Northern Nigeria

Seed morphology and dispersal mechanisms critically influence plant population dynamics, regeneration, and spatial distribution in semi-arid tropical ecosystems. This study examined relationships between seed traits and dispersal patterns of three ecologically and economically important tree species—Albizia lebbeck, Delonix regia, and Azadirachta indica—at the Take-Up Site of the Federal University Dutsin-Ma, Katsina State, Nigeria. A total of 90 seeds per species were collected using systematic quadrat sampling. Seed weight, length, and structural characteristics were measured, while dispersal distances were recorded. Trait–dispersal relationships were analyzed using one-way ANOVA and Pearson correlation. Significant interspecific variation was observed (p < 0.05). Albizia lebbeck produced the smallest and lightest seeds (0.10 ± 0.02 g; 0.91 ± 0.05 cm) and exhibited the greatest dispersal distance (3.19 ± 0.30 m). Delonix regia had the largest seeds (0.44 ± 0.08 g; 1.98 ± 0.15 cm) with shorter dispersal (2.75 ± 0.25 m), while Azadirachta indica showed intermediate traits (0.36 ± 0.07 g; 1.48 ± 0.12 cm) and dispersal distance (2.77 ± 0.28 m). Seed weight and length were strongly negatively correlated with dispersal distance (r = -0.983 and -0.902, p < 0.01). These patterns illustrate the ecological trade-off between dispersal and establishment, where lighter seeds enhance colonization potential while heavier seeds favor seedling survival. Albizia lebbeck is suited for colonizing degraded landscapes, Delonix regia for managed plantings, and Azadirachta indica for adaptive, heterogeneous systems. However, potential limitations related to seed–parent association and unmeasured environmental dispersal drivers should be considered when interpreting these findings. Understanding these trait–dispersal relationships supports evidence-based species selection, propagation strategies, and restoration planning in semi-arid ecosystems

seed morphology, dispersal, Albizia lebbeck, Delonix regia, Azadirachta indica, semi-arid ecosystems, restoration, agroforestry

1. Beckman, N. G., and Rogers, H. S. (2013). Seed dispersal and plant ecology. Journal of Ecology, 101(4), 995–1006. https://doi.org/10.1111/1365-2745.12041 [Google Scholar] [Crossref]

2. Bullock, J. M., Hooftman, D. A. P., and Shipley, B. (2017). Quantifying long-distance dispersal. Trends in Ecology and Evolution, 32(7), 601–611. https://doi.org/10.1016/j.tree.2017.04.006 [Google Scholar] [Crossref]

3. Choudhury, S., Datta, S., and Singh, R. (2016). Seed morphology and dispersal strategies of tropical trees. Tropical Ecology, 57(2), 145–156. [Google Scholar] [Crossref]

4. Corlett, R. T. (2017). Seed dispersal and ecological restoration. Plant Ecology, 218, 1–11. https://doi.org/10.1007/s11258-017-0721-0 [Google Scholar] [Crossref]

5. Couvreur, M., Beckman, N. G., and Muller-Landau, H. C. (2020). Animal-mediated seed dispersal in tropical landscapes. Ecology Letters, 23(2), 200–213. https://doi.org/10.1111/ele.13425 [Google Scholar] [Crossref]

6. Fenner, M., and Thompson, K. (2005). The ecology of seeds. Cambridge University Press. [Google Scholar] [Crossref]

7. Fortuna, M. A., García, C., and Blomberg, S. P. (2023). Challenges in parentage assignment in plant populations. Molecular Ecology, 32(10), 2345–2361. https://doi.org/10.1111/mec.16891 [Google Scholar] [Crossref]

8. Hogan, K. P., and Callaway, R. M. (2020). Seed release height and dispersal outcomes. Journal of Ecology, 108(6), 2543–2556. https://doi.org/10.1111/1365-2745.13430 [Google Scholar] [Crossref]

9. Howe, H. F., and Smallwood, J. (1982). Ecology of seed dispersal. Annual Review of Ecology and Systematics, 13, 201–228. https://doi.org/10.1146/annurev.es.13.110182.001221 [Google Scholar] [Crossref]

10. Kent, M. (2012). Vegetation description and analysis: A practical approach (2nd ed.). Wiley-Blackwell. [Google Scholar] [Crossref]

11. Matlack, G. R. (2016). Wind dispersal in forested environments. Ecography, 39(1), 1–12. https://doi.org/10.1111/ecog.01614 [Google Scholar] [Crossref]

12. Moles, A. T., and Westoby, M. (2004). Seed size and dispersal strategy trade-offs. Journal of Ecology, 92(1), 69–80. https://doi.org/10.1111/j.0022-0477.2004.00868.x [Google Scholar] [Crossref]

13. Nathan, R., Klein, E., Robledo-Arnuncio, J. J., and Revilla, E. (2011). Dispersal kernels and plant spatial dynamics. Ecology Letters, 14(1), 109–121. https://doi.org/10.1111/j.1461-0248.2010.01506.x [Google Scholar] [Crossref]

14. Nathan, R., Soons, M. B., Bullock, J. M., and Schurr, F. M. (2023). Advances in mechanistic dispersal modeling. Annual Review of Ecology, Evolution, and Systematics, 54, 1–28. https://doi.org/10.1146/annurev-ecolsys-120622-091650 [Google Scholar] [Crossref]

15. Saatkamp, A., Affre, L., Dutoit, T., and Poschlod, P. (2019). Seed ecology in semi-arid ecosystems. Perspectives in Plant Ecology, Evolution and Systematics, 38, 125–136. https://doi.org/10.1016/j.ppees.2019.01.003 [Google Scholar] [Crossref]

16. Sacande, M., and Berrahmouni, N. (2018). Seed traits and regeneration in arid ecosystems. Forest Ecology and Management, 429, 1–10. https://doi.org/10.1016/j.foreco.2018.06.013 [Google Scholar] [Crossref]

17. Schleuning, M., Fricke, E. C., and Schweiger, O. (2024). Animal movement and seed dispersal. Functional Ecology, 38(3), 567–580. https://doi.org/10.1111/1365-2435.14375 [Google Scholar] [Crossref]

18. Seidler, T. G., and Plotkin, J. B. (2024). Wind variability and plant dispersal. Ecology, 105(2), e3987. https://doi.org/10.1002/ecy.3987 [Google Scholar] [Crossref]

19. Snell, R. S., et al. (2019). Seed trait correlations with dispersal. Functional Ecology, 33(6), 1157–1169. https://doi.org/10.1111/1365-2435.13309 [Google Scholar] [Crossref]

20. Soons, M. B., Nathan, R., Bullock, J. M., and Schurr, F. M. (2018). Wind dispersal across landscapes. Journal of Ecology, 106(1), 227–241. https://doi.org/10.1111/1365-2745.12882 [Google Scholar] [Crossref]

21. Tackenberg, O., Poschlod, P., and Bonn, S. (2021). Three-dimensional dispersal processes. Ecological Monographs, 91(1), e01428. https://doi.org/10.1002/ecm.1428 [Google Scholar] [Crossref]

22. Thomson, F. J., Moles, A. T., Auld, T. D., and Kingsford, R. T. (2018). Environmental heterogeneity and seed dispersal. Ecography, 41(2), 209–220. https://doi.org/10.1111/ecog.02721 [Google Scholar] [Crossref]

23. Westoby, M., Falster, D. S., Moles, A. T., Vesk, P. A., and Wright, I. J. (2014). Plant functional traits: Theory and applications. Annual Review of Ecology, Evolution, and Systematics, 45, 345–366. https://doi.org/10.1146/annurev-ecolsys-120213-091857 [Google Scholar] [Crossref]

24. Willson, M. F. (1993). Dispersal modes and seedling establishment. Annual Review of Ecology and Systematics, 24, 167–192. https://doi.org/10.1146/annurev.es.24.110193.001123 [Google Scholar] [Crossref]