Demography of the threatened endemic shrub, Arbutus pavarii, in the Al-Akhdar mountainous landscape of Libya

Abstract

We sampled twenty populations of the vulnerable endemic shrub or tree, Arbutus pavarii Pampan., at different elevations and aspects within the Al-Akhdar mountainous region of Libya. Our sampling sites were at elevations ranging from 285 to 738 m above sea level, and several different habitats: vallies (locally known as wadis), north- and south-facing slopes, and mountaintops. All individuals within each quadrat were studied. Population size and structure, and plant functional traits were assessed. None of the populations had a stable distribution of size classes. Some consisted mostly of small plants, with little or no fruit production; others consisted only of mid-sized and large plants, with high fruit production, but no juvenile recruitment. There was a significant increase in percent cover with increasing elevation; reproductive output (the number of fruits per branch and total number of fruits per individual) also generally increased with elevation. In some of these populations the lack of recruitment, and in others the failure to produce fruit, together constituted serious demographic threats. In light of these results, recommendations are made for conservation of this vulnerable endemic species.

Keywords

Al-Akhdar mountains / Conservation / Demography / Elevation / Functional traits / Vulnerable species

References

[1] Acharya BK, Chettri B, Vijayan L. Distribution pattern of trees along an elevation gradient of Eastern Himalaya, India. Acta Oecol, 2011, 37: 329-336.

[2] Alsabri SG, El-Basir HM, Rmeli NB, Mohamed SB, Allafi AA, Zetrini AA, Salem AA, Mohamed SS, Gbaj A, El-Baseir MM. Phytochemical screening, antioxidant, antimicrobialand anti-proliferative activities study of Arbutus pavarii plant. J Chem Pharm Res, 2013, 5: 32-36.

[3] Barrera MD, Frangi JL, Richter LL, Perdomo MH, Pinedo LB. Structural and functional changes in Nothofagus Pumilioforests along an altitudinal gradient in Tierra Del Fuego, Argentina. J Veg Sci, 2000, 11: 179-188.

[4] El Shatshat S. Biological conservation of the endemic Arbutus pavarii Pamp.: seed germination as attempt. Int J Hum Geogr Environ Stud, 2009, 1: 20-22.

[5] El-Darier SM, El-Mogaspi FM. Ethnobotany and relative importance of some endemic plant species at El-Jabal El-Akhdar Region (Libya). World J Agric Sci, 2009, 5: 353-360.

[6] El-Tantawi AM (2005) Climate Change in Libya and Desertification of Jifara Plain. Ph.D. Thesis, Johannes Gutenberg-Universität, p 261

[7] Fenu G, Mattana E, Bacchetta G. Distribution, status and conservation of a critically endangered, extremely narrow endemic: Lamyropsis microcephala (Asteraceae) in Sardinia. Oryx, 2011, 45: 180-186.

[8] Galván JD, Camarero JJ, Gutiérrez E. Seeing the trees for the forest: drivers of individual growth responses to climate in Pinus uncinata mountain forests. J Ecol, 2014, 102: 1244-1257.

[9] Gimingham CH, Walton K. Environment and the scrub communities on the limestone plateau of northern Cyrenaica. J Ecol, 1954, 42: 505-520.

[10] Hamad HH, Habib IH, Gonaid MH, Islam M. Comparative phytochemical and antimicrobial investigation of some plants growing in Al Jabal Al-Akhdar. J Nat Prod Plant Resour, 2011, 1: 15-23.

[11] Hegazy AK. Trade-off between sexual and vegetative reproduction of the weedy Heliotropium curassavicum L. J Arid Environ, 1994, 27: 209-220.

[12] Hegazy AK. Reproductive diversity and survival of the potential annual Diplotaxis harra (Forssk.)Boiss. (Brassicaceae) in Egypt. Ecography, 2001, 24: 403-412.

[13] Hegazy AK, Hammouda O, Lovett-Doust J, Gomaa NH. Population dynamics of Moringa peregrina along altitudinal gradient in the northwestern sector of the Red Sea. J Arid Environ, 2008, 72: 1537-1551.

[14] Hegazy AK, Boulos L, Kabiel HF, Sharashy OS. Vegetation and species altitudinal distribution in Al-Jabal Al-Akhdar landscape, Libya. Pak J Bot, 2011, 43: 1885-1898.

[15] Hegazy AK, Al-Rowaily SL, Faisal M, Alatar AA, El-Bana MI, Assaeed AM. Nutritive value and antioxidant activity of some edible wild fruits in the Middle East. J Med Plants Res, 2013, 7: 938-946.

[16] IUCN. 2013. IUCN Red List of Threatened Species. Version 2013.2. www.iucnredlist.org. Accessed on 08 May 2014

[17] Jafri SM, El-Gadi A (1977/1993) Flora of Libya. Tripoli: Al Fatteh University

[18] Kabiel HF, Hegazy AK, Lovett-Doust L, Al-Rowaily SL, El Borki A. Ecological assessment of populations of Juniperus phoenicea L. in the Al Akhdar mountainous landscape of Libya. Arid Land Res Manag, 2016

[19] Keith HG. Preliminary check list of flora of Libya. 1965, Tripoli: Ministry of agriculture

[20] LNMC Libyan National Meteorological Center. 2012, Tripoli: Climate Research Unit

[21] Louhaichi M, Salkini AK, Estita HE, Belkhir S. Initial assessment of medicinal plants across the Libyan Mediterranean coast. Adv Environ Biol, 2011, 5: 359-370.

[22] Martinell MC, López-Pujol J, Blanche C, Molero J, Sàez L. Conservation assessment of Aquilegia paui (Ranunculaceae): a case study of an extremely narrow endemic. Oryx, 2011, 45: 187-190.

[23] Ping J, Ji Y, Hong-bing D, Guo-fa C. Variations of population structure and importance of or main effects along an elevation gradient on the northern slope of Changbai Mountain. J For Res, 2003, 14: 117-121.

[24] Vilà-Cabrera A, Martínez-Vilalta J, Retana J. Variation in reproduction and growth in declining Scots pine populations. Perspect Plant Ecol Evol Syst, 2014, 16: 111-120.

[25] Wang ZF, Lian JY, Ye WH, Cao HL, Wang ZM. The spatial genetic pattern of Castanopsis chinensis in a large forest plot with complex topography. For Ecol Manage, 2014, 318: 318-325.

[26] Wiegand T, Camarero JJ, Rüger N, Gutiérrez E. Abrupt population changes in tree line ecotones along smooth gradients. J Ecol, 2006, 94: 880-892.