The Status and Extent of Eucalyptus grandis Invasion in Kindoroko Forest Reserve, Mwanga District, Tanzania
الملخص
Early detection and the ability to remove new populations of species showing signs of becoming invasive have been acknowledged as the most cost-effective and effective ways of managing invasive alien species globally. This study assessed the status and extent of Eucalyptus grandis invasion in the Kindoroko Forest Reserve (KFR), located in Mwanga District, Kilimanjaro Region, Tanzania. Specifically, the study aimed to assess (i) the population status and abundance of E. grandis in relation to other woody species in KFR, (ii) the spatial distribution of E. grandis in KFR, and (iii) factors influencing the abundance of E. grandis in KFR. Vegetation data were collected from 60 concentric sample plots of a 15m radius established along 17 cardinal transect lines across the forest area of 885 ha. The study revealed that E. grandis is most abundant near the forest boundary within 50m in comparison with other native species, contributing 44% of the total species counts and accounting for 23% of the overall species counts across the entire forest area. Its abundance and spread are strongly linked to the presence of favourable environmental factors and human disturbances. Canopy cover exhibited a strong negative effect (p<0.001), indicating that invasion decreases with high canopy cover, while slope showed a significant positive relationship (p = 0.044), suggesting that steeper terrains facilitate E. grandis growth. Medium disturbances negatively affected abundance (0.001), meaning decreases in the rate of invasion, whereas high disturbances had a significant positive effect (0.031), meaning invasion increases with increasing disturbances. It is concluded that E. grandis is showing all signs of becoming a problematic species in KFR. Thus, forest management efforts should focus on removing the identified population and reducing disturbances currently occurring in the forest reserve to contribute to mitigating the spread of E. grandis in the KFR.
التنزيلات
المراجع
Benitez-Malvido, J., & Martinez-Ramos, M. (2003). Influence of edge exposure on tree seedling species recruitment in tropical rain forest fragments1. Biotropica, 35(1), 530-541.
Bolker, B. M., Brooks, M. E., Clark, C. J., Geange, S. W., Poulsen, J. R., Stevens, M. H. H., & White, J. S. (2008). Generalized linear mixed models: a practical guide for ecology and evolution. Trends in Ecology & Evolution, 24(3), 127-135.
Buma, B., & Wessman, C. (2011). Disturbance interactions can impact the resilience mechanisms of forests. Ecosphere, 2(5), 1-13.
Charbonneau, N., & Fahrig, L. (2004). Influence of canopy cover and amount of open habitat in the surrounding landscape on the proportion of alien plant species in forest sites. Ecoscience, 11(3), 278-281.
Dawson, W., Moser, D., Van Kleunen, M., Kreft, H., Pergl, J., Pyšek, P., Weigelt, P., Winter, M., Lenzner, B., Blackburn, T. M., Dyer, E. E., Cassey, P., Scrivens, S. L., Economo, E. P., Guénard, B., Capinha, C., Seebens, H., García-Díaz, P., Nentwig, W., … Essl, F. (2017). Global hotspots and correlates of alien species richness across taxonomic groups. Nature Ecology and Evolution, 1(6), 1-7.
Edward, E. (2007). Population status and distribution of a potential invasive alien species, Cordia alliodora, in Amani Nature Reserve, Tanzania. Master’s Thesis, Tanzania, Sokoine University of Agriculture.
Edward, E., Munishi, P. K. T., & Hulme, P. E. (2009). Relative roles of disturbance and propagule pressure on the invasion of humid tropical forest by Cordia alliodora (Boraginaceae) in Tanzania. Biotropica, 41(2), 171-178.
Esseen, P. A., Hedström Ringvall, A., Harper, K. A., Christensen, P., & Svensson, J. (2016). Factors driving the structure of natural and anthropogenic forest edges from temperate to boreal ecosystems. Journal of Vegetation Science, 27(3), 482-492.
Gastauer, M., Massante, J., Ramos, S., Silva, R., Boanares, D., Guedes, R., Caldeira Jr, C., Medeiros-Sarmento, P., de Castro, A., Prado, I., Cardoso, A., Maurity, C., & Ribeiro, P. (2022). Revegetation on tropical steep slopes after mining and infrastructure projects: challenges and solutions. Sustainability, 14(1), 17003.
Getachew, G., Ayalew, A., Gebre hana, K., Wudu, D., Kassahun, H., Tesfaye, A., Alene, M., Redae, T., & Siyum, N. (2024). Evaluate the adaptability of Eucalyptus species in the highlands of the Amhara region. Heliyon, 10(12), e32859.
Gravel, D., Canham, C., Beaudet, M., & Messier, C. (2010). Shade tolerance, canopy gaps and mechanisms of coexistence of forest trees. Oikos, 119(3), 475-484.
Harper, K. A., Macdonald, S. E., Mayerhofer, M. S., Biswas, S. R., Esseen, P. A., Hylander, K., Stewart, K. J., Mallik, A. U., Drapeau, P., Jonsson, B. G., Lesieur, D., Kouki, J., & Bergeron, Y. (2015). Edge influence on vegetation at natural and anthropogenic edges of boreal forests in Canada and Fennoscandia. Journal of Ecology, 103(3), 550-562.
Johnson, D., McCulloh, K., & Reinhardt, K. (2011). The earliest stages of tree growth: development, physiology and impacts of microclimate. In: Meinzer, F., Lachenbruch, B., Dawson, T. (eds). Size-and age-related changes in tree structure and function. Tree Physiology, 4, 65–87. Springer, Dordrecht.
Kardol, P., De Long, J., & Wardle, D. (2014). Local plant adaptation across a subarctic elevational gradient. Royal Society Open Science, 1(3), 140141.
Kerr, T., & Ruwanza, S. (2015). Does Eucalyptus grandis invasion and removal affect soils and vegetation in the Eastern Cape Province, South Africa? Austral Ecology, 41(3), 17.
Kilawe, C. J., Mchelu, H. A., & Emily, C. J. (2022). The impact of the invasive tree Cedrela odorota on the Electric Blue Gecko (Lygodactylus williamsi) and its habitat (Pandanus rabaiensis) in Kimboza Forest Reserve, Tanzania. Global Ecology and Conservation, 38(7), e02225.
Kleinschroth, F., Schöning, C., Kungu, J., Kowarik, I., & Cierjacks, A. (2013). Regeneration of the East African timber tree Ocotea usambarensis in relation to historical logging. Forest Ecology and Management, 291(1), 396-403.
Kowarik, I., & Lippe, M. (2011). Secondary wind dispersal enhances long-distance dispersal of an invasive species in urban road corridors. NeoBiota, 9(1), 49-70.
Kupfer, J., & Runkle, J. (2003). Edge-mediated effects on stand dynamic processes in forest interiors: A coupled field and simulation approach. Oikos, 101(1), 135-146.
Lovett, J., & Pocs, T. (1993). Assessment of the condition of the catchment forest reserves, a Botanical Appraisal. Catchment Forest Project: Ministry of Tourism, Natural Resources and the Environment, Dar es Salaam.
Muñiz-Castro, M. A., Williams-Linera, G., & Benayas, J. (2006). Distance effect from cloud forest fragments on plant community structure in abandoned pastures in Veracruz, Mexico. Journal of Tropical Ecology, 22(1), 431-440.
Musengi, K., & Archibald, S. (2017). Demographics of Eucalyptus grandis and implications for invasion. Koedoe, 59(1), 1-12.
Mwaluseke, M. L., Mwakalukwa, E. E., & Maliondo, S. M. S. (2023). Vegetation composition, diversity, stand structure and carbon stock of a dry evergreen montane forest of Lendikinya forest reserve in Tanzania. Biodiversitas, 24(1), 551-562.
Paletto, A., & Tosi, V. (2009). Forest canopy cover and canopy closure: Comparison of assessment techniques. European Journal of Forest Research, 128(3), 265-272.
Pauchard, A., Kueffer, C., Dietz, H., Daehler, C. C., Alexander, J., Edwards, P. J., Arévalo, J. R., Cavieres, L. A., Guisan, A., Haider, S., Jakobs, G., McDougall, K., Millar, C. I., Naylor, B. J., Parks, C. G., Rew, L. J., & Seipel, T. (2009). Ain’t no mountain high enough: plant invasions reaching new elevations. Frontiers in Ecology and the Environment, 7(9), 479-486.
Popradit, A., Srisatit, T., Kiratiprayoon, S., Yoshimura, J., Ishida, A., Shiyomi, M., Murayama, T., Chantaranothai, P., Outtaranakorn, S., & Phromma, I. (2015). Anthropogenic effects on a tropical forest according to the distance from human settlements. Scientific Reports, 5(3), 1-10.
Rahman, M. M., & Govindarajulu, Z. (1997). A modification of the test of Shapiro and Wilk for normality. Journal of Applied Statistics, 24(2), 219-236.
Raveloaritiana, E., Tscharntke, T., Martin, D., Wurz, A., Osen, K., Soazafy, M., Vorontsova, M., Kreft, H., Rakouth, B., & Grass, I. (2024). Land‐use intensity and relatedness to native plants promote exotic plant invasion in a tropical biodiversity hotspot. Journal of Applied Ecology, 61(1), 1396-1410.
Richardson, D. M, Witt, A.B.R., Pergi, J., Dawson, W., Essl, F., Kreft, H., Kleunen, M., Weigelt, P., Winter, M., & Pyšek, P. (2022). Plant invasion in Africa. In: Clements, D.R., Upadhyaya, M.K., Joshi, S., Shrestha, A (Editors). Global Plant Invasions. pp.225-252. Springer, USA.
Richardson, D., & Rejmanek, M. (2011). Trees and shrubs as invasive alien species–a global review. Diversity and Distributions, 17(1), 788-809.
Rosa, H., Silveira, R., Oliveira, B., Heringer, G., & Zenni, R. (2025). Anthropogenic factors, not altitude, shape native and nonnative plant species distributional patterns in a tropical mountain protected area. Invasive Plant Science and Management, 17(1), 1-8.
Sandoval, J., Julissa, Ackerman, J. D., Marcano-Vega, H., & Willig, M. R. (2022). Alien species affect the abundance and richness of native species in tropical forests: The role of adaptive strategies. Ecosphere, 13(12), 1-18.
Santoro, A., Venturi, M., Bertani, R., & Agnoletti, M. (2020). A review of the role of forests and agroforestry systems in the FAO globally important agricultural heritage systems (GIAHS) programme. Forests, 11(8),1-21.
Stanturf, J. A., Vance, E. D., Fox, T. R., & Kirst, M. (2013). Eucalyptus beyond its native range: Environmental issues in exotic bioenergy plantations. International Journal of Forestry Research, 2013, 1-5.
Steenhuis, T. S., Alemie, T. C., Muche, H., Tilahun, S. A., Zimale, F. A., & Mhiret, D. A. (2023). Effect of eucalyptus on blue and green water availability and discharge in the tropical highlands: An interpretation of available literature. Journal of Hydrology and Hydromechanics, 71(3), 221-230.
TFS (2022). Management plan for Kindoroko Forest Reserve. 66pp (Unpublished).
URT (2019). National Invasive Species Strategy and Action Plan (NISSAP) (2019-2029), 189 Pp.
Waddell, E., Banin, L., Fleiss, S., Hill, J., Hughes, M., Jelling, A., Yeong, K. L., Ola, B., Sailim, A., Tangah, J., & Chapman, D. (2020). Land-use change and propagule pressure promote plant invasions in tropical rainforest remnants. Landscape Ecology, 35(1), 1891-1906.
Wan, J., Rutherford, S., & Bonser, S. (2019). The invasion triangle in the range dynamics of invasive species following successful establishment. Evolutionary Ecology, 33(1), 299-312.
Wang, Z., Du, A., Yuxing, X., Zhu, W., & Zhang, J. (2019). Factors limiting the growth of eucalyptus and the characteristics of growth and water use under water and fertilizer management in the dry season of Leizhou Peninsula, China. Agronomy, 9(1), 590.
Wani, S., Kihuroo, R., Gulzar, R., & Rashid, I. (2022). Diversity, distribution and drivers of alien flora in the Indian Himalayan region. Global Ecology and Conservation, 38(7), e02246.
Yang, X., Li, L., Lv, X., Luo, W., Li, D., Liang, C., Wee, A. K. S., & Long, W. (2021). Closed-canopy tropical forests of Hainan (China) are resilient against invasive herbs and shrubs. Forests, 12(11), 1596-1608.
Zerga, B., Warkineh, B., Teketay, D., & Woldetsadik, M. (2021). The sustainability of reforesting landscapes with exotic species: a case study of eucalypts in Ethiopia. Sustainable Earth, 4(1),
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