Imarhiagbe and Aigbokhan, 2020 Journal of Research in Forestry, Wildlife & Environment Vol. 12(2) June, 2020 E-m a i l : jr fw e 2 0 1 9 @g m a i l .c om ; jfe w r @y a h oo.c om http://www.ajol.info/index.php/jrfwe jfewr ©2020 - jfewr Publications ISBN: 2141 – 1778 This work is licensed under a Creative Commons Attribution 4.0 License 31 Imarhiagbe and Aigbokhan, 2020 STUDIES ON Thonningia sanguinea VAHL. (BALANOPHORACEAE) IN SOUTHERN NIGERIA: III. DISTRIBUTION, HABITAT CHARACTERISTICS AND PHYTOSOCIOLOGY *1 Imarhiagbe, O. and 2Aigbokhan, E. I. 1 Department of Biological Science, Edo University Iyamho, Edo State, Nigeria Department of Plant Biology and Biotechnology, University of Benin, Benin City, Nigeria *Corresponding Author E-mail: imarhiagbe.odoligie@edouniversity.edu.ng;+234 803 198 4621 2 ABSTRACT Apart from the recognition of Thonningia sanguinea as a root parasite of forest trees, information on other aspects such as the nature of its population, habitat preference and distribution range in Nigeria has not been reported. Hence to delineate its presence and current distribution ranges, reconnaissance surveys were carried out across selected forested areas in Southern Nigeria. Records on habitat characteristics comprising host type, elevation, GPS location/orientation, companion plant species, and soil types were collected from sampling sites habouring the plant. This study reports the presence of T. sanguinea in the following locations with an accompanying number of population: Cross River National Park (13), Ehor Nu Wire Forest (3), Okokhuo Forest (3), Okour Forest (2), Iyanomo Forest (2), Okomu National Park (12), Idanre Forest Reserve (2), Ofosu Forest Reserve (3), Oba Hills Forest Reserve (2), IITA Forest Reserve (5), and Omo Forest Reserve (2). Analysis of its habitat features revealed its preference for disturbed habitats, particularly those along forest margins and nature trails, where sunlight reflection reaches the ground. T. sanguinea habitats were characteristically ferrallitic or ferruginous soil. Phytosociological analysis of T. sanguinea habitats showed a regular association with secondary forest indicator species such as Cercestis sp, Harugana madagascariensis, Anchomanes difformis, Musanga cecropioides, Strombosia grandifolia, Icacina trichantia, Myrianthus arboreus. Thus, based on habitat preference, T. sanguinea can best be described as a species that avoid a highly disturbed environment but show a preference for areas with minimal disturbance in a forested environment. Consequently, T. sanguinea could be a potential bioindicator in predicting environmental degradation in a forested ecosystem. Keywords: Habitat characteristics, bioindicator, phytosociology, parasitic plant. INTRODUCTION The distribution pattern and habitat characteristics are key aspects of the ecology of parasitic plants. Parasitic plants are an intriguing group of species, essentially, by the partial or complete undermining of their fundamental photosynthetic role as independent plants to become dependent on other plant species for survival (Heide-Jørgensen, 2008; Santos et al., 2017). Owing to the specialized habitat requirements of parasitic plants, their distribution among plant communities is largely influenced by host availability, host quality, host resistance to parasitism, and parasite preference (Garcia-Franco and Rico-Gray, 1996; Norton and Carpenter, 1998; Norton and Lange, 1999; Press and Phonex 2005). Although most authors postulate that host species are the key determinant of the distribution pattern of parasitic plants (Watson, 2009; Joel et al., 2013), other environmental conditions might affect such a synchronous distribution pattern. According to Zhang et al. (2018), the distribution of a parasitic plant synergistically results from an interaction between biological (i.e., dispersal vector and host availability) and environmental factors (i.e., altitude, area, longitude, and latitude). Therefore understanding the host-parasite interaction in relation to habitat features is key to proper JOURNAL OF RESEARCH IN FORESTRY, WILDLIFE AND ENVIRONMENT, VOLUME 12, NO. 2 JUNE, 2020 STUDIES ON Thonningia sanguinea VAHL. (BALANOPHORACEAE) IN SOUTHERN NIGERIA: III. DISTRIBUTION, HABITAT CHARACTERISTICS AND PHYTOSOCIOLOGY understanding of the ecology of parasitic plants and this has often been a challenge for conservation biologists (Marvier and Smith 1997; Santos et al., 2017). Thonningia sanguinea Vahl. of the Balanophoraceae, is an obligate parasitic flowering plant, notable for its unusual development and obscure affinities. It is a fleshy dioecious herb that grows from an underground yellow tuber that extends horizontally through the soil and forms a bulb-like swelling at the points where it attaches to the roots of its host plants (Imarhiagbe and Aigbokhan, 2019). The stem is coated with spirals of scale-like leaves that lack chlorophyll; hence, it obtains its nutrients solely from the hosts. The flowering stem emerges from the ground to produce a bright red or pink inflorescence. Although commonly considered as a weed especially in rubber plantations (Idu et al., 2002), T. sanguinea is highly revered for its medicinal properties (Olanya and Eilu, 2009; Imarhiagbe, 2020). A number of studies have been carried out on other aspects of the plant. Amongst these are, its gall anatomy (Idu et al., 2002), its pollination system (Goto et al., 2011), and its ethnobotany (Imarhiagbe, 2020). Thonningia sanguinea has also been reported to possess antibacterial activity (N'guessan et al., 2007), antioxidant activity (Gyamfi et al., 1999) and according to Ouattara et al. (2007), T. sanguinea may potentially harbor the healing properties to treat HIV and AIDS infection. Based on the present narrative, it is evident that a fundamental aspect relating to sustainable survival in the wild has not been looked into. Thonningia sanguinea is restricted to the humid inland forests where it uses various tree roots as host. Recent reports indicate that these forested habitats are being faced with escalating high rates of degradation (Bani et al., 2006; Piratelli et al., 2008; Leimu, 2010), resulting in potential loss of host plants, thereby impacting negatively on the parasite population. More so, considering the current limited knowledge on the germination mechanism of T. sanguinea which up till now, remains elusive among scientists, the only viable option is to identify with current wild populations and proffer ways of conserving the plant in situ. Therefore, an understanding of its distribution, host species, and habitat features become an important prerequisite 32 step necessary for making informed conservation management decisions. Hence, the present study was conducted based on the following objectives: (i) delineate the scope of the distribution (ii) identify its host species and (iii) determine its habitat preferences in Southern Nigeria. MATERIALS AND METHODS Description of study sites Thonningia sanguinea populations are not randomly distributed but restricted to forested environments comprising a suitable host. Therefore, forested locations in Southern Nigeria, comprising National Parks, Forest Reserves and community-managed secondary forests, habouring T. sanguinea was mapped out and used as study sites. A brief description of the sites is given below. The Okomu National Park, Edo State is located between longitude 5o E and 5o 30' E and latitude 6oN and 6oN, about 75 km west of Benin City, Nigeria. The park has a forest habitat that spans an area of 1,082 km2 and it is further divided into different segments of about 1.6km2 each. The climate has a well-marked rainy and dry reasons. The mean annual rainfall and temperature are 2,100 mm and 30.2 o C respectively. The relative humidity is usually not less than 65 percent during the day in any month of the year (Olaniyi et al., 2015). Oba Hills division of the Cross River National Park is 2,800 km2 in area, centered on coordinates 5°25′0″ N 8°35′0 E″. The division shares a long border with Korup National Park in the Republic of Cameroon, forming a single protected ecological zone. It has a rugged terrain, rising from 100 m in the river valleys to over 1,000 m in the mountains. The soils are highly vulnerable to leaching and erosion. The rainy season normally starts from March to November, with an annual rainfall of over 3,500 mm. The forest remains largely untouched in the less accessible areas, but around the margins, it has been considerably degraded by human activity. The Park is divided into the buffer zone and the main park. Akure Ofosu Forest Reserve is situated in Southwest Nigeria and with a land cover of over 394 km2. It is located between latitude 5° 12´ and 5°30´N, longitude 50´and 7° 05´E, in the humid, JOURNAL OF RESEARCH IN FORESTRY, WILDLIFE AND ENVIRONMENT, VOLUME 12, NO. 2 JUNE, 2020 Imarhiagbe and Aigbokhan, 2020 33 tropical rainforest zone of Ondo State, Nigeria (Ogunjemite and Oates, 2011). The forest has two distinct seasons (rainy and dry), with an annual rainfall (March to November) ranging from 1,500 to 2,000 mm and mean annual temperature between 30°C and 32°C while the mean daily humidity is 70%. Akure Ofosu Forest Reserve is currently experiencing a decrease in the vegetation cover due to anthropogenic activities, especially from logging and conversion of Forestlands to cocoa farms through forest encroachment. IITA Forest Reserve is located in Ibadan, between Ojoo and Moniya town. The forest reserve covers about 350 hectares. It lies in the transition zone between equatorial rainforest to the south and savanna to the north. The Forest is a dry semideciduous rainforest. There is a pronounced dry season beginning in November and lasting until March. The average rainfall is 1301.6 mm with average monthly rainfall being lowest in January (1.6 mm) and highest in July (189.7 mm) (Bown, 2013). Idanre Forest Reserve has been deeply encroached by anthropogenic activities, resulting in a single patch of natural forest at its Centre. The eastern side of the forest reserve has been converted to teak plantations and farms. There are many camps on this side of the reserve, indicating a high human population. The size of the remaining forest could not be quantified but it is probably less than 50 km2. Oba Hills Forest Reserve is situated in Osun State, Nigeria. The vegetation covers an area of about 52 km2 of hilly terrain. Presently, the forest reserve is faced with degradation as almost all of the reserves have been converted to plantations and farms. Omo Forest Reserve is a preserved area of tropical rainforest in Ogun state, Nigeria. The reserve covers an area of 130,500 hectares (322,000 acres) with mixed vegetation types. In the northern part, the vegetation consists of a dry evergreen moist, deciduous forest, while in the south, it is a moist, mixed, semi-deciduous forest. The average rainfall is around 2,000 mm. Recent reports indicate that a large portion of the reserve have been significantly disturbed, with the felling of the original trees and the establishment of plantations (Ojo, 2004) Iyanomo rubber plantation is situated in the Rubber Research Institute of Nigeria (RRIN), Edo State. It is the only agency in the country mandated to conduct research into the production and development of Hevea brasiliensis. To complement the National Parks and Forest Reserves, some community forests were also visited. They include Ehor Nu Wire Community Forest, Okokhuo Community Forest, Okuor Community Forest, all in Edo State. Figure 1. Map of Nigeria (Inset) Showing Study Sites in Selected Southern States JOURNAL OF RESEARCH IN FORESTRY, WILDLIFE AND ENVIRONMENT, VOLUME 12, NO. 2 JUNE, 2020 STUDIES ON Thonningia sanguinea VAHL. (BALANOPHORACEAE) IN SOUTHERN NIGERIA: III. DISTRIBUTION, HABITAT CHARACTERISTICS AND PHYTOSOCIOLOGY Experimental Design To plot the distribution range of T. sanguinea populations, two reconnaissance studies by road were conducted to delineate the current distribution and identify its presence and absence across these locations (study sites). Supplementary information from historical records on T. sanguinea including ethnobotanical information was obtained from oral interviews of indigenous people living around the study sites and this was used to complement visual observations. A distribution map was drawn with the ArcGIS software (ver. 1.6) using geo-reference data collected. The habitat characteristics of T. sanguinea were observed and recorded using descriptors such as host species, nature of habitat (sunny or shaded), elevation and GPS location/orientation, nature of soil (data on the nature of soil were espoused from the 34 characterization of the forest of Southern Nigeria according to Hall (1977). A vegetation survey was conducted to check plant species that appeared more often in plots with Thonningia sanguinea. Plant species found growing within the vicinity of 10 m × 10 m of the quadrat surrounding where T. sanguinea stands were spotted and identified, recorded and subjected to phytosociological analysis. Vegetative analysis parameters such as relative values of frequency, density, abundance and the importance value of each species were analyzed according to the methodology outlined by Kuchler et al. (1976). Identification of host and associated plant species was carried out using plant identification guides e.g Hutchinson and Dalziel (1968); Applequist (2001); Steentoft (2008); Aigbokhan (2014); Akobundu et al. (2016). Figure 2: A closeup of Thonningia sanguinea inflorescence at the Okomu National Park, Edo State. (A) Male plant (B) Female plant (C) & (D) Aggregated nature of the population. RESULTS Figure 2 depicts the potential and confirmed distribution of Thonningia sanguinea in Southern Nigeria. The study revealed its presence in the following locations with accompanying number of populations: Cross River National Park (13), Ehor Nu Wire Forest (3), Okokhuo Forest (3), Okour Forest (2), Iyanomo Forest (2), Okomu National Park (12), Idanre Forest Reserve (2), Ofosu Forest Reserve (3), Oba hills forest Reserve (2), IITA Forest Reserve (5), and Omo Forest Reserve (2). These populations were supported by the following host species Hevea brasiliensis, Theobroma cacao, Guarea cedrata, Lophira alata, Musanga cecropiodes, Myrianthus arboreus, and Ricinodendron heudelotii, within the distribution range. JOURNAL OF RESEARCH IN FORESTRY, WILDLIFE AND ENVIRONMENT, VOLUME 12, NO. 2 JUNE, 2020 Imarhiagbe and Aigbokhan, 2020 35 Figure 3: Potential and confirmed distribution of Thonningia sanguinea in Southern Nigeria JOURNAL OF RESEARCH IN FORESTRY, WILDLIFE AND ENVIRONMENT, VOLUME 12, NO. 2 JUNE, 2020 STUDIES ON Thonningia sanguinea VAHL. (BALANOPHORACEAE) IN SOUTHERN NIGERIA: III. DISTRIBUTION, HABITAT CHARACTERISTICS AND PHYTOSOCIOLOGY 36 Table 1: Host Species and Habitat Characteristics of Sites Harbouring Thonningia sanguinea in Southern Nigeria Study Sites State Located Altitude (m) Coordinates Habitat Characteristics/ host plants Soil Type of Source/Parent Rocks* Okomu National Park Edo 51.40 - 102.6 06°24.113” 005° 19.440”E 06°21.381” 005°19.889” E 06°20.937” 005°20.685” E 06°20.135” 005°20.470” E 06°21.062” 005°21.398” E 06°21.656” 005°21.587” E Common along forest trails and edges where sunlight penetrates to the ground. Host species include Myrianthus arboreus, Musanga cecropiodes Guarea cedreta, Ricinodendron heudelotii Ferrallitic soils-western subgroup. Cenozoic sands Cross River National Park Cross River 123.6 - 167.6 05°21.863ʹʹ 008°26.438ʹʹ E 05°22.172” 008° 26.182” E 05°21.863” 008° 26.438” E 05°21.925” 008°26.350” E 05°21.863” 008°26.438” E Abundant in disturbed portion of the forest, especially along the forest walk way. Sunlight reflection also observed. Host species include Lophira alata and Musanga cecropioides Ferrallitic soils. Soil particles highly compact. Basement complex Idanre Forest Reserves Ondo 196.6 07°01.954” 005°09.868” E Secondary forest type, found growing amidst Theobroma cacao plantation. Ferruginous tropical soil- wet subgroup. Basement complex IITA Forest Reserves Oyo 214.5 07°29.820” 003°53.530” E Secondary forest type. T. sanguinea common along the disturbed portion of the forest especially along the forest walk way, with much sunlight reflection to the ground. Host unknown. Ferruginous tropical soil-Dry sub soil group. Basement complex Ofosu Forest Reserves Ondo 188.6 06°43.278” 005°07.852” E Secondary forest type, common along forest walkway. Found parasitizing Musanga cecropioides. Ferruginous tropical soil-Dry sub soil group. Basement complex Oba hills forest Reserves Osun 253.3 07°45.275” 004°07.752” E Secondary forest type. Disturbed portion of the forest. Found along the forest walk way, with much sunlight reflection to the ground. Host unknown. Ferruginous tropical soil-Dry sub soil group. Basement complex Omo Forest Reserves Ogun ?? ?? Secondary forest type. Disturbed portion of the forest. Found along the forest walk way, with much sunlight reflection to the ground. Host Ficus sp Ferruginous tropical soil-Dry sub soil group. Basement complex JOURNAL OF RESEARCH IN FORESTRY, WILDLIFE AND ENVIRONMENT, VOLUME 12, NO. 2 JUNE, 2020 Imarhiagbe and Aigbokhan, 2020 37 ?. Edo 99.1 Okokhuo Forest Edo 25.3 Okour Forest Edo 148.6 Iyanomo Forest Edo 35.3 06°18.342” 005° 48.598” E Plantation forest, with attributes of a forest re- growth physiognomy, comprising predominantly of Hevea brasiliensis. Host species observed was H. brasiliensis Plantation forest, with attributes of a forest re- growth physiognomy, comprising predominantly of Hevea brasiliensis. Host species observed was H. brasiliensis Ferrallitic soils-central sub-group less compact soil particles. Cenozoic sands. 06°11.962” 006° 04.928” E Plantation forest, with attributes of a forest re- growth physiognomy, comprising predominantly of Hevea brasiliensis. Host species observed was H. brasiliensis Ferrallitic soils-central sub-group Coarse litter, with relatively undecomposed plant materials. Cenozoic sands 06°09.746” 005°34.898” E Found in large patches among stands of the host species-H. brasiliensis. Ferrallitic soils-central sub-group less compact soil particles. Cenozoic sands Ehor Nu Wire Forest 06°34.909” 005° 36.415” E *Soil types and parent material characterization adopted from Hall (1977) JOURNAL OF RESEARCH IN FORESTRY, WILDLIFE AND ENVIRONMENT, VOLUME 12, NO. 2 JUNE, 2020 Ferrallitic soils-central subgroup. Cenozoic sands STUDIES ON Thonningia sanguinea VAHL. (BALANOPHORACEAE) IN SOUTHERN NIGERIA: III. DISTRIBUTION, HABITAT CHARACTERISTICS AND PHYTOSOCIOLOGY 38 Figure 4: The regular nature-trail habitat preference of Thonningia sanguinea; parasitizing host trees along the forest trails (sites identity: A- Okomu N. P.; B- Okokhuo C.F; C- Ofosu F. R.; D- IITA F.R.; ECross River N. P.). Legend: N.P (National Park), C.F. (Community Forest), F.R. (Forest Reserves) JOURNAL OF RESEARCH IN FORESTRY, WILDLIFE AND ENVIRONMENT, VOLUME 12, NO. 2 JUNE, 2020 Imarhiagbe and Aigbokhan, 2020 39 Table 2: Importance value index (IVI) of plant species growing at Thonningia sanguinea sites in Southern Nigeria Associated Plant Species with Thonningia sanguinea Hevea brasiliensis Cercestis sp. Harugana madagascariensis Theobroma cacao Rinorea breviracemosa Anchomanes difformis Musanga cecropioides Strombosia grandifolia Icacina trichantia Adenia lobata Smilax anceps Myrianthus arboreus Alchornea cordiflora Cleistopholis patens Pteris togolensis Periploca sp. Trema orientalis Acanthus montanus Albizia lebbeck Clerodendrum sp. Leea guineensis Funtamia elastic Lophira alata Acacia ataxacantha Macaranga barteri Costus afer Allanblankia floribunda Megaphrynium sp. Relative Frequency Relative Density Relative Abundance Important Value (R.F.) (R.D.) (R.A.) (I.V.) 2.56 3.84 4.23 1.28 1.67 2.17 2.96 2.96 1.67 1.28 2.17 2.56 1.28 2.17 1.67 0.89 0.89 1.67 2.17 1.67 1.28 2.17 2.17 0.89 1.28 1.28 1.67 0.89 7.01 6.63 5.69 3.79 3.79 3.22 2.65 2.46 2.46 2.27 2.27 2.08 2.08 2.08 2.08 1.7 1.7 0.76 1.52 1.52 1.52 1.33 1.33 1.33 1.14 1.9 1.52 1.33 3.63 2.57 1.96 3.92 2.94 1.99 1.18 1.09 1.91 2.35 1.41 0.88 2.15 1.18 1.61 2.64 2.64 2.35 0.94 1.18 1.57 0.822 0.822 2.05 1.76 0.98 0.94 1.91 13.20 13.04 11.88 8.99 8.40 7.38 6.79 6.51 6.04 5.90 5.85 5.52 5.51 5.43 5.36 5.23 5.23 4.78 4.63 4.37 4.37 4.32 4.32 4.27 4.18 4.16 4.13 4.13 JOURNAL OF RESEARCH IN FORESTRY, WILDLIFE AND ENVIRONMENT, VOLUME 12, NO. 2 JUNE, 2020 STUDIES ON Thonningia sanguinea VAHL. (BALANOPHORACEAE) IN SOUTHERN NIGERIA: III. DISTRIBUTION, HABITAT CHARACTERISTICS AND PHYTOSOCIOLOGY Associated Plant Species with Thonningia sanguinea Carapa procera Alchornea laxiflora, Laportea aestuans Ricinodendron heudelotii Voacanga Africana Memecylon spatada Trichilia monadelpha Nauclea latifolia Alstonia boonei Cola millenii Uapaca guineensis Barteria fistolosa Artocarpus altilis Parkia bicolor Cola heterophylla Manniophytun fluvum Pycanthus angolensis Sterculia tragacantha Pentaclethra macrophylla Triplochiton scleroxylon Strophanthus hispidus Albizia zygia Ancistrophyllum sp.. Anthocleista vogelii Ceiba pentandra Cola gigantean Desplatsia dewevrei Elaeis guineensis Palisota hirsute Sphenocentrum jollyanum Treculia Africana 40 Relative Frequency Relative Density Relative Abundance Important Value (R.F.) (R.D.) (R.A.) (I.V.) 1.67 1.28 0.89 1.67 1.67 1.28 1.28 0.89 1.28 1.28 1.28 1.28 0.89 0.89 1.28 0.39 0.89 0.89 1.28 1.28 0.89 0.89 0.89 0.89 0.89 0.89 0.89 0.89 0.89 0.89 0.89 1.33 1.33 1.14 1.14 1.14 1.14 1.14 0.94 0.95 0.95 0.95 0.76 0.76 0.76 0.76 0.57 0.38 0.38 0.57 0.57 0.32 0.57 0.57 0.57 0.57 0.57 0.57 0.57 0.57 0.57 0.57 1.03 1.37 1.76 0.88 0.88 1.18 1.18 1.47 0.98 0.98 0.98 0.88 1.18 1.18 0.78 1.76 1.18 1.18 0.58 0.58 1.18 0.88 0.88 0.88 0.88 0.88 0.88 0.88 0.88 0.88 0.88 4.03 3.98 3.79 3.69 3.69 3.60 3.60 3.30 3.21 3.21 3.21 2.92 2.83 2.83 2.82 2.72 2.45 2.45 2.43 2.43 2.39 2.34 2.34 2.34 2.34 2.34 2.34 2.34 2.34 2.34 2.34 JOURNAL OF RESEARCH IN FORESTRY, WILDLIFE AND ENVIRONMENT, VOLUME 12, NO. 2 JUNE, 2020 Imarhiagbe and Aigbokhan, 2020 41 Associated Plant Species with Thonningia sanguinea Zanthoxylum sp. Klainedoxa gabonensis Maesobotrya barteri Tetracera alnifolia Annickia chlorantha Anonidium mannii Baphia nitida Ceitis zenkeri Diospyros mespiliformis Guarea cedreta Pausinystalis johimbe Ancistrocladus korupensis Bridelia ferruguinea Entadrophragma angolense Ficus sp. Holarrhena floribunda Lovoa trichilioides Microdesmis peribula, Monodora myristica Monodora tenuifolia Oeceoclades maculate Paristolochia goldiena Relative Frequency Relative Density Relative Abundance Important Value (R.F.) 0.89 0.39 0.39 0.39 0.89 0.89 0.89 0.89 0.89 0.89 0.39 0.39 0.39 0.39 0.39 0.39 0.39 0.39 0.39 0.39 0.39 0.39 (R.D.) 0.57 0.38 0.38 0.38 0.38 0.38 0.38 0.38 0.38 0.38 0.19 0.19 0.19 0.19 0.19 0.19 0.19 0.19 0.19 0.19 0.19 0.19 (R.A.) 0.58 1.18 1.18 1.18 0.58 0.58 0.58 0.58 0.58 0.58 0.58 0.58 0.58 0.58 0.58 0.58 0.58 0.58 0.58 0.58 0.58 0.58 (I.V.) 2.04 1.95 1.95 1.95 1.85 1.85 1.85 1.85 1.85 1.85 1.16 1.16 1.16 1.16 1.16 1.16 1.16 1.16 1.16 1.16 1.16 1.16 JOURNAL OF RESEARCH IN FORESTRY, WILDLIFE AND ENVIRONMENT, VOLUME 12, NO. 2 JUNE, 2020 STUDIES ON Thonningia sanguinea VAHL. (BALANOPHORACEAE) IN SOUTHERN NIGERIA: III. DISTRIBUTION, HABITAT CHARACTERISTICS AND PHYTOSOCIOLOGY DISCUSSION The study established a relatively wide range of distribution for T. sanguinea, detecting the presence of nineteen populations in the following locations Ehor Nu Wire forest (Edo), Iyanomo forest (Edo), Okour forest (Edo), Okokhuo forest (Edo), Okomu National Park (Edo), Cross River National Park (Cross River), Idanre Forest Reserve (Ondo), Ofosu Forest Reserve (Ondo), Oba Hills Forest Reserve (Osun) Omo Forest Reserve (Ogun) and IITA Forest Reserve (Oyo). However, ethnobotanical investigations carried out attested to its potential presence in Bayelsa, Ogun, Delta, Kogi, Benue, and Taraba States. At first notice in the forest, T. sanguinea are found in aggregated patches, clustered around the vicinity of the host plant (figure 2d). Such a contagious pattern of distribution is expected of species that are associated with specific resources, in this case, the host species. However, there are some implications to such distribution pattern as stated by Santos et al. (2017), that impaired vegetative growth and reduced seed dispersal may be associated with a clumped distribution of this nature and this could further result in interference of resource use and interspecific interactions among generated forms of aggregated individuals. On a broad scale, it appears that the general distribution pattern of T. sanguinea in Nigeria corresponds to areas where forest vegetation is still present. Meaning that the rate of forest degradation which is currently on the rise may likely have a negative effect on the present distribution of T. sanguinea. Consequently, the absence of T. sanguinea in places such as Enugu, Imo, Anambra, and Ebonyi States is attributed to the depleted nature of the forests, thereby creating a partial savannah-like environment that is not habitable to T. sanguinea (figure 3). Another interesting finding was that the presence or absence of host plant in a forest habitat was not a major determinant of the occurrence of T. sanguinea because even with the presence of host species, T. sanguinea was markedly absent in some areas. For instance, no account of T. sanguinea was noticed in the Ogba Zoo and Nature Park, a wet tropical lowland rainforest in Edo State, despite the abundance of common host species like Myrianthus arboreus and Musanga cecropioides in the Park. 42 Such a pattern of occurrence suggests that host plants appear not to be critical in the prevalence of T. sanguinea and also reflect the heterogeneity of the forest habitat as a whole. However, most T. sanguinea habitats were observed to possess good drainage with a moist-soft soil texture which allows for the upward growth of the inflorescence. Thonningia sanguinea population were found on several forest soil types in Southern Nigeria, comprising: dry sub group ferruginous tropical soil, wet subgroup ferruginous tropical soil, western subgroup ferralitic soil, central sub-group ferralitic soil, and southern sub-group ferralitic soil. Sites habouring Thonningia sanguinea were marked by disturbances and hence they were always found growing on forest path or trails, forest edge, and secondary forests brought about by the conversation of the original forest vegetation to plantations. The recurrent incidence on forest edges and nature trails was constant in all locations and it reveals the preference of T. sanguinea for disturbed areas of the forest preferably, areas along forest margins with much sunlight penetration to the ground. Analysis of its phytosociology shows that the following plant species namely Hevea brasiliensis, Cercestis sp., Harugana madagascariensis, Theobroma cacao, Rinorea breviracemosa, Anchomanes difformis, Musanga cecropioides, Strombosa grandifolia, Icacina trichantia, Adenia lobata, Smilax anceps, Myrianthus arboreus, Alchornea cordifolia, and Cleistopholis patens were regularly found growing around the vicinity of T. sanguinea. Plant species association with respect to a particular species of interest can give insightful clues to the nature of the habitat. Most of the above listed associated species of T. sanguinea are “sun-loving” secondary forest indicator species (Martin 1991; Aubréville and Bossanyi, 2015; Oluwokudejo and Oyetola, 2016). Hence, this corroborates the earlier observed preference of T. sanguinea for disturbed areas of the forest environment. Ecroyd (1996) reported a similar pattern of habitat preference for Dactylanthus taylorii (Balanophoraceae) in New Zealand. The generalization of this unique pattern of habitat preference for members of Balanophoracae can only be affirmed in due course when the habitat characteristics of other members of Balanophoraceae are revealed. JOURNAL OF RESEARCH IN FORESTRY, WILDLIFE AND ENVIRONMENT, VOLUME 12, NO. 2 JUNE, 2020 Imarhiagbe and Aigbokhan, 2020 43 CONCLUSION The study has evaluated the distribution, habitat characteristics, and phytosociology of Thonningia sanguinea in Southern Nigeria. A total of 49 T. sanguinea populations were found parasitizing Hevea brasiliensis, Theobroma cacao, Guarea cedrata, Lophira alata, Musanga cecropioides, Myrianthus arboreus, and Ricinodendron heudelotii. Analysis of its habitat features indicated its preference for disturbed habitats along forest margins and nature trails. The phytosociological analysis revealed its close association with species such as Cercestis sp, Harugana madagascariensis, Anchomanes difformis, Musanga cecropioides, Strombosia grandifolia, Icacina trichantia, Myrianthus arboreus. The consistent presence of T. sanguinea along footpaths, the disturbed portion of the forest, and preference for key secondary forest re-growths species such as Musanga cecropiodes and Myrianthus arboreus as host, suggest it as a potential bio-indicator in predicting environmental degradation in a forested ecosystem. REFERENCES Aigbokhan, E. I. (2014). Annotated checklist of vascular plants of southern Nigeria-a quick reference guide to the vascular plants of southern Nigeria: a systematic approach, Uniben Press, Benin City. Pp.1-346. Akobundu, I. O., Ekeleme, F., Agyakwa, C.W. and Ogazie, C.A. (2016). A handbook of West African weeds. International Institute of Tropical Agriculture, Ibadan, Nigeria. Pp.1 – 381. Applequist, W. L. (2001). Taxonomic keys. Plant Sciences. [Online] [Available at: http://www.encyclopedia.com]. (Accessed: 26 June, 2017). Aubréville, A., and Bossanyi, I. (2015). Secondary Forests in Equatorial Africa Côte d’Ivoire Cameroon-F.E.A. Bois & Forets Des Tropiques. 323(323): 19. Bani, L. Massimino, D. Bottoni, L. and Massa, R. (2006). A Multiscale Method for Selecting Indicator Species and Priority Conservation Areas: a Case Study for Broadleaved Forests in Lombardy, Italy. Conservation Biology. 20 (2): 512-526. Bown, D. (2012). Common Plants of IITA. International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria. 136p. Ecroyd C. E. (1996). The ecology of Dactylanthus taylorii and threats to its survival. New Zealand Journal of Ecology. 20(1): 81-100. Goto, R. Yamakoshi, G. and Matsuzawa, T. (2011). A novel brood-site pollination mutualism?: the root holoparasite Thonningia sanguinea (Balanophoraceae) and an inflorescencefeeding fly in the tropical rainforests of West Africa. Plant Species Biology. 27(2): 164– 169. Gyamfi, M. A. Yonamine, M. and Aniya, Y. (1999). Free-radical scavenging action of medicinal herbs from Ghana. General Pharmacology: The Vascular System. 32(6): 661–667. Hall, J. B. (1977). Forest-Types in Nigeria: An analysis of pre-exploitation forest enumeration data. Journal of Ecology. 65(1): 235-247. Heide-Jorgensen, H. S. (2008). Parasitic Flowering Plants Parasitic Flowering Plants. Brill, Leiden, The Netherlands. Pp. 1-438. Hutchinson, J. and Dalziel, J. M., (1968). Flora of West Tropical Africa. Crown Agents for Overseas Governments and Administrations, London, Pp. 1-276. Idu, M., Begho, E. R. Akpaja, E. O. (2002). Anatomy of attachment of the root parasite Thonningia sanguinea Vahl.on Hevea brasiliensis. Indian Journal of Rubber Research. 15(1): 33–35. Imarhiagbe, O. (2020). Prospects of Ethnobotanical Uses of Thonningia sanguinea Vahl. (Balanophoraceae) among selected tribes in southern Nigeria. Journal of Medicinal Plant Studies. 8(2):126-132. Imarhiagbe, O. and Aigbokhan, E. I. (2019). Thonningia sanguinea Vahl. (Balanophoraceae) in Southern Nigeria: II. Patterns of genetic diversity and population Acknowledgments This work was completely funded by the TETFUND 2017-2018 (Batch 12th) Research Project (RP) Intervention. The authors are grateful to the invaluable assistance provided by the management of the various National Parks and Forest Reserves. We also appreciate the efforts of Park Rangers that assisted in field sampling and data collections. JOURNAL OF RESEARCH IN FORESTRY, WILDLIFE AND ENVIRONMENT, VOLUME 12, NO. 2 JUNE, 2020 STUDIES ON Thonningia sanguinea VAHL. (BALANOPHORACEAE) IN SOUTHERN NIGERIA: III. DISTRIBUTION, HABITAT CHARACTERISTICS AND PHYTOSOCIOLOGY structure within and between Populations. Makara Journal of Science, 23 (4): 193-203 Joel D. M. Gressel J. and Musselman L. J. (2013). Parasitic Orobanchaceae: Parasitic mechanisms and control strategies. Berlin: Springer; https://doi.org/10.1007/978-3-64238146-1 Kuchler, A. W. Mueller-Dombois, D. and Ellenberg, H. (1976). Aims and methods of vegetation ecology. Geographical Review. 66(1): 114. Leimu, R. (2010). Habitat quality and population size as determinants of performance of two endangered hemiparasites. Fennian Botanical Annals. 47(1): 1–13. Martin, C. (1991). Forest Conservation Past and Present. The Rainforests of West Africa, Pp. 202–217. Marvier, M. A. and Smith, D. L. (1997). Conservation implications of host use for rare parasitic plants. Conservation Biology. 11(4): 839–848. N’guessan, J. D. Dinzedi, M. R. Guessennd, N. Coulibaly, A. Dosso, M., Djaman, A. J. and Guede-Guina, F. (2007). Antibacterial activity of the aqueous extracts of Thonningia sanguinea against ExtendedSpectrum-b-Lactamases (ESBL) producing Escherichia coli and Klebsiella pneumonia strains. Tropical Journal of Pharmaceutical Research. 6(3):779-783 doi:10.4314/tjpr.v6i3.14659. Norton, D. A. and De Lange, P. J. (1999). Host specificity in parasitic mistletoes (Loranthaceae) in New Zealand. Functional Ecology. 13(4): 552–559. Ogunjemite, B. G. and Oates, J. F. (2011). Assessment of the chimpanzee populations In Akure-Ofosu forest reserve, southwestern Nigeria. Journal of Research in Forestry, Wildlife and Environment. 3 (2): 32-38 Ojo, L.O. (2004). The fate of a tropical rainforest in Nigeria: Abeku sector of Omo Forest Reserve. Global Nest: The International Journal, 6 (2): 116–130. 44 Olaniyi, O.E.; Ogunjemite, B.G., Akindele, S.O (2015). Ecotourism development in Okomu National Park, Nigeria. Journal of Sustainable Development in Africa, 17 (7): 51-74 Olanya, C. A., and Eilu, G. (2009). Host-parasite relations of an angiospermous root parasite (Thonningia sanguineaVahl) in logged and unlogged sites of Budongo forest reserve, western Uganda. African Journal of Ecology. 47(3): 328–334. Olowokudejo, J. D. and Oyebanji, O. O. (2016). Floral diversity of the littoral vegetation of Southeastern Nigeria. International Journal of Biodiversity and Conservation. 8(12): 320– 333. doi:10.5897/ijbc2016.1027. Ouattara, B. Kra, A. M., Coulibaly, A. and GuedeGuina, F. (2007). Efficiency of ethanol of Thonningia sanguinea against Cryptococcus neoformans. African Health Sciences. 17 (4): 219–22. Piratelli, A. Sousa, S. Corrêa, J. Andrade, V. Ribeiro, R. Avelar, L. and Oliveira, E. (2008). Searching for bioindicators of forest fragmentation: passerine birds in the Atlantic forest of southeastern Brazil. Brazilian Journal of Biology. 68(2): 259–268. Press, M. C. and Phoenix, G. K. (2005). Impacts of parasitic plants on natural communities. New Phytologist. 166(3): 737–751. Santos, J. C. Nascimento, A. R. T. Marzinek, J., Leiner, N. and Oliveira, P. E. (2017). Distribution, host plants and floral biology of the root holoparasite Langsdorffia hypogaea in the Brazilian savanna. Flora. 226: 65–71. Steentoft, M. (2008). Flowering Plants in West Africa. Cambridge University Press. Pp.1- 350. Watson, D. M. (2009). Determinants of parasitic plant distribution: the role of host quality. Botany. 87(1): 16–21. Zhang, G., Li, Q. and Sun, S. (2018). Diversity and distribution of parasitic angiosperms in China. Ecology and Evolution. 8(9): 4378–4386. JOURNAL OF RESEARCH IN FORESTRY, WILDLIFE AND ENVIRONMENT, VOLUME 12, NO. 2 JUNE, 2020