Effects of Broussonetia papyrifera invasion and land use on vegetation characteristics in a tropical forest of Ghana

Abstract

The purpose of this study was to evaluate the effects of Broussonetia papyrifera (paper mulberry) invasion and land use on the floristic composition of a dry semi-deciduous forest in Ghana. Forty-five plots (25 m × 25 m each), distributed among three land uses—selectively logged (SL); abandoned farmlands (AF); and an undisturbed reference (RF)—were surveyed. Results showed lower tree species richness (S), diversity (H′), evenness (S) and basal area (BA) in the SL (46, 0.78, 0.32 and 269.12 m² ha⁻¹, respectively) and AF (40, 0.53, 0.45, and 131.16 m² ha⁻¹) sites compared to the RF site (79, 2.66, 0.87, 963.72 m² ha⁻¹). Similar patterns were found at the shrub layer, but no differences were observed at the herb layer. Non-metric multidimensional scaling ordination revealed distinct species composition among the land uses. The two disturbed habitats, SL and AF, were associated with increased B. papyrifera invasion particularly in the overstory, with importance value index and mean relative density of 45 and 65.03%, and 42 and 53.29%, correspondingly. However, the species was only sparsely represented in the RF site. Tree density of B. papyrifera correlated negatively with H′, S, E, BA, and native tree density and richness. These findings highlight the strong link between human land use (i.e., logging and slash-and-burn farming), invasion, and vegetation characteristics, and suggest the need to limit these disturbances to conserve biodiversity within tropical forest ecosystems.

Keywords

Afram Headwaters Forest Reserve / Broussonetia papyrifera / Forest community characteristics / Human-caused disturbances / Plant invasion

References

[1] Addo-Fordjour P, Obeng S, Anning AK, Addo MG. Floristic composition, structure and natural regeneration in a moist semi-deciduous forest following anthropogenic disturbances and plant invasion. Int J Biodivers Conserv, 2009, 1: 021-037.

[2] Anning AK, Yeboah-Gyan K. Diversity and distribution of invasive weeds in Ashanti Region, Ghana. Afr J Ecol, 2007, 45: 355-360.

[3] Anning AK, Akyeampong S, Addo-Fordjour P, Anti KK, Kwarteng A, Tettey YF. Floristic composition and vegetation structure of the KNUSTBotanic Garden, Kumasi, Ghana. J Sci Technol, 2008, 28: 103-116.

[4] Apetorgbor MM, Bosu PP. Occurrence and control of paper mulberry (Broussonetia papyrifera) in Southern Ghana. Ghana J For, 2011, 27: 40-51.

[5] Avery TE, Burkhart HE. Forest measurements, 2002 5 New York: McGraw-Hill 456

[6] Barney JN, Tekiela DR, Dollete ESJ, Tomasek BJ. What is the “real” impact of invasive plant species?. Front Ecol Environ, 2013, 11: 322-329.

[7] Begon M, Townsend CR, Harper JL. Ecology: from individuals to ecosystems, 2006 4 Malden: Blackwell Science Ltd. 738

[8] Biswas SR, Mallik AU. Disturbance effects on species diversity and functional diversity in riparian and upland plant communities. Ecology, 2010, 91: 28-35.

[9] Bosu PP, Apetorgbor MM, Refera A. Kohli RK, Shibu J, Singh HP, Batish DR. Ecology and management of tropical Africa’s forest invaders. Invasive plants and forest ecosystems, 2009, Boca Raton: Taylor and Francis Group 355 375

[10] Bosu PP, Apetorgbor MM, Nkrumah EE, Bandoh KP. The impact of Broussonetia papyrifera (L.) vent. on community characteristics in the forest and forest– savannah transition ecosystems of Ghana. Afr J Ecol, 2013, 51: 528-535.

[11] Brent CB, Letourneau DK, Bothwell SG, Hayes GF. Disturbance, resources, and exotic plant invasion: gap size effects in a redwood forest. Madroño, 2010, 57: 11-19.

[12] Caño L, Escarré J, Sans FX. Factors affecting the invasion success of Senecio inaequidens and S. pterophorus in Mediterranean plant communities. J Veg Sci, 2007, 18: 281-288.

[13] Catford JA, Daehler CC, Murphy HT, Sheppard AW, Hardesty BD, Westcott DA, Rejmanek M, Bellingham PJ, Pergl J, Horvitz CC, Hulme PE. The intermediate disturbance hypothesis and plant invasions: implications for species richness and management. Perspect Plant Ecol Evol Syst, 2012, 14: 231-241.

[14] Catford JA, Vesk PA, Richardson DM, Pysek P. Quantifying levels of biological invasion: towards the objective classification of invaded and invasible ecosystems. Glob Change Biol, 2012, 18: 44-62.

[15] Chisholm R. Levin SA. The ecology, economics, and management of alien invasive species. The Princeton guide to ecology, 2009, Princeton: Princeton University Press 731 739

[16] Connell JH. Diversity in tropical rain forests and coral reefs. Science, 1978, 199: 1302-1310.

[17] Davis MA, Grime JP, Thompson K. Fluctuating resources in plant communities: a general theory of invasibility. Ecology, 2000, 88: 528-534.

[18] Duggin JA, Gentle CB. Experimental evidence on the importance of disturbance intensity for invasion of Lantana camara L. in dry rainforest-open forest ecotones in north-eastern NSW, Australia. For Ecol Manag, 1988, 109: 279-292.

[19] Dwomoh FK (2009) Forest fire and carbon emission from burnt tropical forest: the case study of Afram Headwaters Forest Reserve, Ghana (Master’s thesis, International Institute for Geo-Information Science and Earth Observation Enschede). Kumasi, Ghana: the Netherlands and Kwame Nkrumah University of Science and Technology, 50

[20] Foster DR, Motzkin G, Slater B. Land use history as long-term, broad scale disturbance: regional forest dynamics in central New England. Ecosystems, 1998, 1: 96-119.

[21] Franklin J, Serra-Diaz JM, Syphard AD, Regan HM. Global change and terrestrial plant community dynamics. PNAS, 2016, 113: 3725-3734.

[22] Hall JB, Swaine MD. Distribution and ecology of vascular plants in a tropical rain forest: forest vegetation of Ghana, 1981, Dordrecht: Springer 383

[23] Hawthorne W, Gyakari N. Photoguide for the forest trees of Ghana: a tree-spotter’s guide for identifying the largest trees, 2006, Oxford: Oxford Forestry Institute 432

[24] Hawthorne W, Jongkind C. Woody plants of Western African forests: a guide to the forest trees, shrubs, and lianes from Senegal to Ghana, 2006, Kew: Royal Botanic Gardens 1023

[25] Hawthorne WD, Abu-Juam M, Gyakari N, Ekpe P (1999) Plants in Ankasa, Nini-Suhien and Bia: Review of existing knowledge, results from a new survey and recommendations for management plans. Ghana Wildlife Department Project financed by the European Union (Project No. 6 ACP/GH045). Western Region, Ghana, Wildlife Division of the Forestry Commission, Ghana

[26] Hobbs RJ, Huenneke LF. Disturbance, diversity and invasion: implications for conservation. Conserv Biol, 1992, 6: 324-337.

[27] Isaac ME, Gordon AM, Thevathasan N, Oppong SK, Quashie-Sam J. Temporal changes in soil carbon and nitrogen dynamics in tropical multistrata agroforestry systems: a chronosequence of pools and fluxes. Agrofor Syst, 2005, 65: 23-31.

[28] Mack RN, Simberloff D, Lonsdale WM, Evans H, Clout M, Bazzaz FA. Biotic invasions: causes, epidemiology, global consequences, and control. Ecol Appl, 2000, 10: 689-710.

[29] McIntyre S, Lavorel S. How environmental and disturbance factors influence species composition in temperate Australian grasslands. J Veg Sci, 1994, 5(3): 373-384.

[30] Oksanen J, Blanchet FG, Kindt R, Legendre P, Minchin PR, O’Hara RB, Simpson GL, Solymos P, Stevens MHH, Wagner H (2015) Vegan: Community Ecology Package. R package.version 2.3-0. http://CRAN.R-project.org/package=vegan/. Accessed 1 Jan 2015

[31] Perrings C, Williamson M, Barbier EB, Delfino D, Dalmazzone S, Shogren J, Simmons P, Watkinson A. Biological invasion risks and the public good: an economic perspective. Conserv Ecol, 2002 6 1 1

[32] Pimentel D, Zuniga R, Morrison D. Environmental and economic costs of non- indigenous species in the United States. Bioscience, 2000, 50: 53-65.

[33] R Core Team (2016) R: a language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. http://www.R-project.org/. Accessed 1 Jan 2015

[34] Sala OE, Chapin FS III, Armesto JJ, Berlow E, Bloomfield J, Dirzo R, Huber-Sanwald E, Huenneke LF, Jackson RB, Kinzig A, Leemans R, Lodge DM, Mooney HA, Oesterheld M, Poff NL, Sykes MT, Walker BH, Walker M, Wall DH. Global biodiversity scenarios for the year 2100. Science, 2000, 287: 1770-1774.

[35] Simberloff D, Martin J-L, Genovesi P, Maris V, Wardle DA, Aronson J, Courchamp F, Galil B, Garcia-Berthou E, Pascal M, Pysek P, Sousa R, Tabacchi E, Vila M. Impacts of biological invasions: what’s what and the way forward. Trends Ecol Evol, 2013, 28: 58-66.

[36] The Plant List (2013) Version 1.1. Published on the Internet; http://www.theplantlist.org/. Accessed 1st May 2015

[37] Turner MG, Collins SL, Lugo AL, Magnuson JJ, Rupp TS, Swanson FJ. Disturbance dynamics and ecological responses: the contribution of long-term ecological research. Bioscience, 2003, 53: 46-56.

[38] Uriarte M, Canham CD, Thompson J, Zimmerman JK, Murphy L, Sabat AM, Fetcher N, Haines BL. Natural disturbance and human land use as determinant of tropical forest dynamics: results from a forest simulator. Ecol Monogr, 2009, 79(3): 423-443.

[39] van Andel TR. The use of distance measures in phytosociological sampling. Ecology, 2003, 47: 451-460.

[40] Vila M, Espinar JL, Hejda M, Hulme PE, Jarosik V, Maron JL, Pergl J, Schaffner U, Sun Y, Pysek P. Ecological impacts of invasive alien plants: a meta-analysis of their effects on species, communities and ecosystems. Ecol Lett, 2011, 14: 702-708.

[41] Whistler WA, Elevitch CR (2006) Broussonetia payprifera (paper mulberry). In: Elevitch CR (ed) Species profiles for Pacific Island Agroforestry, Permanent Agriculture Resources. Hawaii. http://www.clshade.net/agroforestry/tti/Broussonetia-papermulb.pdf. Accessed 22 April 2014