An assessment of population structure and regeneration status of Magnolia punduana Hk. f. & Th. (Magnoliaceae) in fragmented forests of northeast India

Abstract

The population structure and regeneration status of Magnolia punduana Hk. f. & Th., an endemic tree species of northeast India were investigated in fragmented forests in the Jarain Hills and in adjoining areas of Meghalaya state. The population structure was discontinuous in all the fragments with the absence of individuals in higher diameter classes. The number of individuals increased with the size of the fragment patches (p < 0.004). The density of mature trees (≥ 5 cm dbh) was high (24–30 individuals ha⁻¹) in the largest fragment (> 105 ha). The number of seedlings and saplings were also higher in the larger fragments. Human-related disturbances had a negative impact on the species population (p < 0.002). Variation in the population density in different forest patches has been attributed to fragment size, site characteristics and ongoing human disturbances. The restricted distribution of the species coupled with exploitation and habitat destruction underlines the need for its conservation.

Keywords

Conservation / Disturbance / Fragmentation / Magnolia punduana / Restricted distribution

References

[1] Aizen MA, Feinsinger P. Forest fragmentation, pollination and plant reproduction in a Chaco dry forest, Argentina. Ecology, 1994, 75: 330-351.

[2] Balakrishnan NP. Flora of Jowai, 1981, Howrah: Botanical Survey of India 305

[3] Bustamante RO, Castor C. The decline of an endangered ecosystem: the Ruil (Nothofagus alessandrii) forest in central Chile. Biodivers Conserv, 1998, 7: 1607-1626.

[4] Cayuela L, Golicher DJ, Benayas JMR, González-Espinosa M, Ramírez-Marcial N. Fragmentation, disturbance and tree diversity conservation in tropical montane forests. J Appl Ecol, 2006, 43: 1172-1181.

[5] Champion HG, Seth SK. A revised survey of forest types of India, 1968, Delhi: Government of India Press 404

[6] Choudhury BI, Khan ML. Conservation and management of endangered plant species: a case study from Northeast India. Biorem Biodivers Bioavailab, 2010, 4: 47-53.

[7] Choudhury BI, Khan ML, Arunachalam A, Das AK (2007) Ecology and conservation of the critically endangered tree species Gymnocladus assamicus in Arunachal Pradesh, India. Res Lett Ecol, Article ID 59282. https://doi.org/10.1155/2007/59282

[8] Cox CB, Moore PD. Biogeography, 1993, Oxford: Blackwell Scientific Publications 326

[9] Duchok R, Kent K, Khumbongmayum AD, Paul A, Khan ML. Population structure and regeneration status of medicinal tree Illicium griffithii in relation to disturbance gradients in temperate broad—leaved forest of Arunachal Pradesh. Curr Sci, 2005, 89: 673-676.

[10] Farwig N, Berens DG. Imagine a world without seed dispersers: a review of threats, consequences and future directions. Basic Appl Ecol, 2012, 13: 109-115.

[11] Fensham RJ, Bowman DMJS. Stand structure and the influence of overwood on regeneration in tropical eucalyptus forest in Melville island. Aust J Bot, 1992, 40: 335-352.

[12] Franklin SE. Remote sensing for sustainable forest management, 2001, Boca Raton: Lewis Publishers Inc. 407

[13] Galetti M, Donatti CI, Pires AS, Guimarães PR Jr, Jordano P. Seed survival and dispersal of an endemic Atlantic forest palm: the combined effects of defaunation and forest fragmentation. Bot J Linn Soc, 2006, 151: 141-149.

[14] Gazoul J, Listen KA, Boyle TJB. Disturbance induced density-dependent seed set in Shorea siamensis (Dipterocarpaceae) a tropical forest tree. J Ecol, 1998, 86: 462-473.

[15] Haridasan K, Rao RR. Forest flora of Meghalaya, 1985, Dehradun: Bishen Singh Mehandrapal Singh 450

[16] Herbert J. Distribution, habitat and red list status of the New Caledonian endemic tree Canacomyrica monticola (Myricaceae). Biodivers Conserv, 2006, 15: 1459-1466.

[17] Heywood VH, Mace GM, May RM, Stuart SN. Uncertainties in extinction rates. Nature, 1994, 368: 105.

[18] Holsinger KE, Gottlieb LD. The conservation of rare and endangered plants. Trends Ecol Evol, 1989, 7: 193-194.

[19] Iralu V, Upadhaya K. Notes on Magnolia punduana Hk. F. & Th. (Magnoliopsida: Magnoliales: Magnoliaceae): an endemic and threatened tree species of northeastern India. J Threat Taxa, 2015, 7: 7573-7576.

[20] Iralu V, Upadhaya K. Dormancy, storability and germination of seeds in Magnolia punduana (Magnoliaceae). Botany, 2016, 94: 967-973.

[21] IUCN (2014) The IUCN red list of threatened species. Version 2014. 2. www.iucnredlist.org

[22] Jennersten O. Pollination in Dianthus deltoids (Caryophyllaceae): effects of habitat fragmentation on visitation and seed set. Conserv Biol, 1988, 2: 359-366.

[23] Kadavul K, Parthasarathy N. Population analysis of Alphonsea sclerocarpa Thw. (Annonaceae) in the Kalyaran Hills of Eastern Ghats India. Int J Ecol Environ Sci, 2001, 27: 51-54.

[24] Kalliovirta M, Ryttari T, Heikkinen RK. Population structure of a threatened plant, Pulsatilla patens, in boreal forests: modeling relationships to overgrowth and site closure. Biodivers Conserv, 2006, 15: 3095-3108.

[25] Kanjilal UN, Kanjilal PC, Das A, De RN, Bor NL. Flora of Assam, 1934, Shillong: Government Press 386

[26] Khan ML, Bhuyan P, Tripathi RS. Regeneration of Rudraksh (Elaeocarpus ganitrus Roxb.)—a threatened tree species: germination strategies. Int J Ecol Environ Sci, 2003, 29: 255-260.

[27] Luoga EJ, Witkowski ETF, Balkwill K. Regeneration by coppicing (resprouting) of miombo (African savanna) trees in relation to land use. Forest Ecol Manage, 2004, 189: 23-35.

[28] McGarigal K. El-Shaarawi AH, Piegorsch WW. Landscape pattern metrics. Encyclopedia of environmetrics, 2002, Sussex: Wiley 1135 1142

[29] Mir AH, Iralu I, Pao NT, Chaudhury C, Khonglah CG, Chaudhary KL, Tiwari BK, Upadhaya K. Magnolia lanuginosa (Wall.) Figlar & Noot. in West Khasi Hills of Meghalaya, northeastern India: re-collection and implications for conservation. J Threat Taxa, 2015, 8: 8398-8402.

[30] Mittermeier RA, Gil PR, Hoffmann M, Pilgrim J, Brooks T, Mittermeier CG, Lamoreux J, Da Fonseca GAB. Hotspots revisited. Earth’s biologically richest and most endangered terrestrial ecoregions, 2004, Mexico City: Agrupacion Sierra Madre 390

[31] Moxham C, Turner V. The effect of fragmentation on the threatened plant community Coastal Moonah Woodland in Victoria, Australia. Urban Ecosys, 2011, 14: 569-583.

[32] Navarro L, Guitián J. Seed germination and seedling survival of two threatened endemic species of the northwest Iberian Peninsula. Biol Conserv, 2003, 109: 313-320.

[33] Nayar MP, Sastry ARK. Red data book of Indian plants, 1990, Calcutta: Botanical Survey of India 271

[34] Parthasarathy N, Karthikeyan R. Population structure of Grewia pandaica—a rare and endemic tree species of southwest India. Int J Ecol Environ Sci, 1997, 23: 85-90.

[35] Qiu YL, Parks CR, Chase MW. Molecular divergence in the eastern Asia eastern North America disjunct section Rytidospermum of Magnolia (Magnoliaceae). Am J Bot, 1995, 82: 1589-1598.

[36] Rundel PW. Mooney HA, Winner WE, Pell EJ. Shrub life-forms. Response of plants to multiple stresses (Physiological ecology series), 1991, New York: Academic 345 370

[37] Saikia P, Khan ML. Population structure and regeneration status of Aquilaria malaccensis Lam. in homegardens of Upper Assam, northeast India. Trop Ecol, 2013, 54: 1-13.

[38] Sukumar R, Dattaraja HS, Suresh HS, Radhakrishnan J, Vasudeva R, Nirmala S, Joshi NV. Long-term monitoring of vegetation in a tropical deciduous forest in Mudumalai, Southern India. Curr Sci, 1992, 62: 608-616.

[39] Tang CQ, Li YH, Zhang ZY. Species diversity patterns of natural secondary plant communities and man-made forests in a subtropical mountainous Karst area, Yunnan, SW China. Mt Res Dev, 2010, 30: 244-251.

[40] Tang CQ, Zhao MH, Li XS, Ohsawa M, Ou XK. Secondary succession of plant communities in a subtropical mountainous region of SW China. Ecol Res, 2010, 25: 149-161.

[41] Tang CQ, Yang Y, Ohsawa M, Momohara A, Hara M, Cheng S, Fan S. Population structure of relict Metasequoia glyptostroboides and its habitat fragmentation and degradation in south-central China. Biol Conserv, 2011, 144: 279-289.

[42] Trejo I, Dirzo R. Deforestation of seasonally dry tropical forest: a national and local analysis in Mexico. Biol Conserv, 2000, 94: 133-142.

[43] Upadhaya K, Barik SK, Adhikari D, Baishya R, Lakadong NJ. Regeneration ecology and population status of a critically endangered and endemic tree species (Ilex khasiana Purk.) in north-eastern India. J For Res, 2009, 20: 223-228.

[44] Upadhaya K, Thapa N, Lakadon NJ, Barik SK, Sarma K. Priority areas for conservation in Northeast India: a case study in Meghalaya based on plant species diversity and endemism. Int J Ecol Environ Sci, 2013, 39: 125-136.

[45] Veblen TT, Schegel SM, Escobar RB. Structure and dynamics of old growth Nothofagus forest in the Valdivian Andes, Chile. J Ecol, 1980, 68: 1-31.

[46] Walter KS, Gillett HJ. IUCN red list of threatened plants. Compiled by the World Conservation Monitoring Centre, 1998, Gland: The World Conservation Union 862

[47] Wheeler L, Rivers MC (2015) Magnolia punduana. The IUCN red list of threatened species 2015: e.T31237A2802522. http://dx.doi.org/10.2305/IUCN.UK.2015-2.RLTS.T31237A2802522.en