Assessment of Trees and Vegetation Cover in Calintaan Island
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ASSESSMENT OF TREES AND VEGETATION COVER IN CALINTAAN ISLAND, MATNOG, SORSOGON Abitria, Mary Rose, Albuero, Irene, Atanacio, Nobe, Baltar, Elica Jana, Baylon, Febbie Faye, Chan, Billy, Gosim, Sheila Mae, Jimenez, Francis Joseph King, Manalang, Rashel, Mandapat, Mark Kevin, Maristela, Jill Prescious, Nicerio, Jar Romsal, Rabulan, Lyn Mae, Villanueva, Mark, Zarate, Rhodelyn
Department of Biology Bicol University College of Science, Legazpi City ABSTRACT An assessment of arbors and vegetation in Calintaan Island, Matnog, Sorsogon was done to determine the present status of its diversity. In trees, a total of 295 individuals was recorded using the quadrat sampling technique. The species, which was recorded from three stations, belong to 38 different species and under 34 genera. Pterocarpus indicus stood out with 95.257% importance value followed by Cocos nucifera (38.512%) and Shorea negronensis (26.323%). These tree species are notably the most sought after trees because of their great quality in lumber. Station 3 got the highest Shannon-Weiner Index of 2.69 followed by Station 1 with 2.59 and Station 2 with 2.44. It could be noted that a high Shannon-Weiner Index resulted to low Simpson’s index. Thus, having low Simpson’s Index will yield a high Evenness index that will give the status of species richness in the station. In vegetation, a total of 10,143 individuals of plants was recorded from the 1 kilometer transect line using the line intercept technique that was composed of three stations. The total number of individuals belongs to 56 different species wherein 44 of which were identified that come from 41 genera. As of record, 12 species were unidentified wherein one species was identified up to its family level only. High importance value index was manifested on P. conjugatum (33.501%), A. aciculatus (32.491%) and unidentified sp. 37 (26.910%). Station 2 had the highest diversity and evenness with 2.391 and 0.667, respectively and got the lowest Simpson’s index wherein there’s a very low chance that a plant species will dominate. Stations 1 and 2 got the lowest H values. This primarily shows that human interventions greatly affect the species richness of an area. Researchers recommend further studies on the tree and vegetation cover of the island by adding more stations and transects. Furthermore, frequent monitoring on the biodiversity status of the island is highly recommended. Introduction Located at the Southern tip of Luzon, the province of Sorsogon is the gateway to the south of Philippines. Awed by the wild vegetation around it, the succulent environment of the forest and the idyllic mixture of the wildlife's enchanting aura, foreign tourists have dubbed it "Switzerland of the Orient" (RFU5, Sorsogon).
Matnog, a third class, partially urban municipality in the second district of Sorsogon boasts its rolling hills and valleys that are carpeted with varying foliage of mostly untracked tropical soil and seen as a humble town with affluent myriad of natural sights. These are the unbounded strips of pristine beaches along its coastline, turquoise waters and thickly forested
mountains comprised together as an ultimate destination for both leisure and adventure tourism (LGU Profile, Matnog, Sorsogon, 2006). Aside from agriculture, fishery and mining, beach resorts and natural attractions are also potential economic activities. Indeed, nature has showered the province with soon to be explored and pristine tourists’ attractions including Calintaan Island where undisturbed, serene white beaches are located. Calintaan is really a perfect site to study its trees and plant biodiversity. While plant conservation has found a place in the global arena, efforts at the national and local levels appear to be more focused in the conservation of wild fauna. Published studies about the Philippines' vegetation/tree covers are still limited up to date. The Assessment of Trees and Vegetation in Calintaan Island, Matnog, Sorsogon was conducted using the Quadrat Sampling Technique and Line Intercept Technique, correspondingly. The quadrat sampling allows the researcher to define a fixed plot, within which plant characters can be measured. It usually attempts to define plant community characteristics for an area much larger than the actual area sampled (Gerardo et.al, 2007). On the other hand, line intercept method is a common and objective way to assess cover by laying down a transect tallying up how much of a plant intersects the transect. It is a popular method used to estimate population density. The probability density of perpendicular sighting distances from randomly placed transect lines are modeled to derive an estimate population density (Gerardo et.al, 2007).
With this study it can fill up the present knowledge of the Philippine plants and trees which can provide information of how many and what species are extinct, threatened or near-threatened. It'll pave the way for the construction of projects or programs on plant resources conservation and will inspire several individuals and institutions to undertake activities/measures to conserve Philippine flora. It will eventually lead to the discovery of novel compounds that could be useful in the treatment of different diseases. Moreover, this will fuel the influx for more researches in Calintaan Island and other nearby islands of Sorsogon and will serve as baseline of data for future researchers. In showcasing the diversity in size, form, and color of the plants, the researchers hope to give the opportunity to appreciate the beauty of the Philippine forests. Such awareness will hopefully translate into protecting the very source of our food, medicine, water, clothing, shelter, electricity, and minerals. In due time Calintaan Island will progress into a tourism hub which may greatly affect the ecosystem in the area. Thus, the study generally aims to assess the diversity of plants and trees in Calintaan Island, Matnog, Sorsogon. It specifically aims the following: 1. To identify the species of trees and plants recorded; 2. To determine the relative density, relative frequency, relative cover and importance value of each species found in the area; and 3. Evaluate the numerical means of describing community composition using the Shannon-Weiner Index, Simpson Index of Dominance, Evenness Index and Similarity Index.
Methodology Sampling Site Calintaan Island is a barangay in Matnog, Sorsogon which is making waves in terms of tourism arrival. Its center lies at 12°32'23"N and 124°6'26"E with an elevation of 34 meters above sea level (http://www.travelsradiate.com/asia/republic -of-the-philippines/bicol/1720267-calintaanisland.html). Figure 1 shows the map of Calintaan Island in Matnog, Sorsogon. Surrounded by pristine beaches and rolling hills and valleys this island is surely a tourist’s tropic getaway from the noise and stress of the city.
Figure 1 Station 1
and counted. The diameter at breast high was measured 1.3 meters above the ground. Measurement was recorded in centimeters and will be rounded to the nearest 0.1cm.
150m Figure 4 Outline for Tree Sampling
Figure 2 Station 2
For trees, three stations with 15 quadrats each that measures 10x10m was set up (Fig.4), covering a total of 450 meters in the arboreal region of Calintaan Island, Matnog, Sorsogon. The three stations were located in different areas of the island. Station 1 (Fig. 1) was near the shoreline, Station 2 (Fig. 2) was at the middle of the forest and Station 3 (Fig.3) at the slope of the hill. The quadrats were established in an alternating pattern on each side. All tree species within the quadrats were identified
Figure 3 Station 3
For vegetation cover, a 1 kilometer transect line (Fig. 8) was laid out in Calintaan Island, Matnog, Sorsogon. Furthermore, it was divided into three stations measuring 300 meters with a 50 meter interval from each station. Station 1 (Fig. 5) was found near the beach. On the other hand, Station 2 (Fig. 6) at the grassland portion of the forest and Station 3 (Fig. 7) at the top of the hill.
Figure 5 Station 1
Figure 6 Station 2
1000 meters Figure 8 Outline for Vegetation Cover Sampling
Figure 7 Station 3
through the photos that were sent to them. Others were identified with the help of Herbarium specimens form Bicol University Department of Biology. Statistical Analysis The following ecological formulas were used to analyze the data gathered in the study of trees.
Plant species that intercept each line were identified, counted and measured. Only the plant species touched by the transect line were recorded. Measurement was recorded in centimeters and was rounded to the nearest 0.1cm. Figure 10 shows a brief structural pattern in the island. The trees were identified by collecting samples of leaves (some with fruits/flowers) of each species and by taking pictures of the tree and plant per se. Identification was made through Co’s Digital Flora of the Philippines which was built on the late Mr. Leonardo L. Co’s checklist of Philippine plants and his large collection of plant photographs. Other species were identified through books and with the help of some researchers in UPLB
Where: DBH= Diameter at Breast Height
Simpson’s Index of Dominance
The following ecological formulas were used to analyze the data gathered in the study of vegetation cover.
Where: D= Simpson’s Index of Dominance n = Number of individual per species N= Total number of individuals of all species Evenness Index
Where: H= Shannon-Weiner Index of Diversity ln=Natural Log N= Total number of species Similarity Index
Shannon-Weiner Index of Diversity
Where: S= Similarity Index K= Number of Species common to the 3 stations A= Number of Species found in Station 1
Where: B= Number of Species found in Station 2 H = the Shannon diversity index C= Number of Species found in Station 3 Pi = fraction of the entire population made up of species i S = numbers of species encountered ∑ = sum from species 1 to species S
Results and Discussion A total of two hundred ninety-five (295) individuals of trees was recorded from the three stations, measuring 150 meters each, in Calintaan Island, Matnog, Sorsogon. The sampling was conducted using the quadrat sampling technique. The trees belong to thirty-eight (38) different species and come from thirty-four genera (34). These species come from twenty-seven (27) families namely: Arecaceae (1), Anacardiaceae (1), Apocynaceae (3), Anonaceae (1) Boranginaceae (1), Burseraceae (2), Cannabaceae (1), Combretaceae (1), Clusiaceae (1), Dilleniaceae (1). Dipterocarpaceae (2), Euphorbiaceae (1), Fabaceae (3), Lamiaceae (1), Lauraceae (1), Meliaceae (2), Mimosaceae (1), Moringaceae (1), Moraceae (6), Myrtaceae (1), Olaceae (1), Palmaeae (1), Rutaceae (1), Sapindaceae (1), Sapotacea (1), Sterculiaceae (1) and Verbaceae (1). It is shown in Table 1 that Cocos nucifera has the highest number of individuals (48) that is 16.271% of all tree species collected. C. nucifera was evident due to coco farming. Remnants of coconut logging were also seen in the area. Shorea negronensis comes next with forty two individuals (42) that is 14.237 % relative density and Alstonia scholaris with twentyeight (28) individuals or 9.4917%. In the rate of occurrence in the stations, it was C. nucifera that was the most frequent with 14.814%. It is followed by S. negronensis with 11.57% and A. scholaris with 7.870%. In terms of relative cover, it is Pterocarpus indicus that got the highest with 87.70% which is listed as vulnerable by the IUCN. Therefore, its population is slowly declining and proper protection and conservation must be enforced. C. nucifera
followed with 7. 426% and T. catappa with 3.268%. The importance value weighs the status of the tree species with respect to its relative density, relative frequency and relative cover. Thus, it is P. indicus that stood out with 95.257 % importance value followed by C. nucifera (38.512%) and S. negronensis (26.323%). These tree species listed are notably the most sought after trees because of their great quality in lumber especially P. indicus. 0.884 0.863 0.882
0.077 0.103 0.087
2.69 2.44 2.59
Figure 9 Comparison of the Ecological Indices in the 3 Stations
Figure 9 shows the comparison between the different ecological indices in the three stations. Station 3 got the highest Shannon-Weiner Index of 2.69 followed by Station 1 with 2.59 and Station 2 with 2.44. It could be noted that a high ShannonWeiner Index resulted to low Simpson’s index. Therefore, if a station is highly diverse, it would have a low chance of having a certain tree species that would dominate the area. Thus, having low Simpson’s Index will yield a high Evenness index that will point out the species richness in the station. The Similarity Index value is 21% since there are only four species that were common in the three stations. Meaning, there is a 21% chance of seeing common species in the stations. With such value, there is still a good variation of tree species in Calintaan Island.
Table 1 Tree Species Composition of Calintaan Island, Matnog, Sorsogon
Pterocarpus indicus Cocos nucifera Shorea negronensis Alstonia scholaris Voacanga globosa Celtis luzonica Artocarpus ovatus Terminalia catappa Vitex parviflora Mangifera indica Ficus stipulosa Gmelina arborea Moringa oleifera Planchonella nitida Anona muricata Plumeria rubra Ficus nota Leucena glauca Dillenia philippinensis Ptychosperma macarthurii Artocarpus blancoi Artocarpus altilis Sandoricum koetjape Cordia dichotoma Canarium ovatum Persea americana Shorea guiso Strombosia philippinensis Psidium guajava Nephelium lappaceum Tamarindus inidca Antiaris toxicaria Calophyllum inophyllum Citrus decumana Balakata luzonica Gliricidia sepium Aglaia edulis Guazuma ulmifolia
Narra Niyog Mahogany Dita Bayag-usa Magabuyo Anubing Talisay Molave Mango Balete Gmelina Malunggay Duklitan Abokado Kalachuchi Tibig Ipil-ipil Mcarthur palm Antipolo Bread fruit Santol Anonang Pili Avocado Tamayuan Bayabas Rambutan Sampalok Upas Palomaria Lucban Balakatgubat Madredecacao langsatan Guazuma
10 48 42 28 24 14 11 6 12 9 10 8 6 6 6 8 4 4 4 4 3 5 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1
3.389830508 16.27118644 14.23728814 9.491525424 8.13559322 4.745762712 3.728813559 2.033898305 4.06779661 3.050847458 3.389830508 2.711864407 2.033898305 2.033898305 2.033898305 2.711864407 1.355932203 1.355932203 1.355932203 1.355932203 1.016949153 1.694915254 0.677966102 0.677966102 0.677966102 0.677966102 0.677966102 0.677966102 0.677966102 0.338983051 0.338983051 0.338983051 0.338983051 0.338983051 0.338983051 0.338983051 0.338983051 0.338983051
4.166667 14.81481 11.57407 7.87037 7.407407 5.092593 4.62963 2.777778 3.703704 4.166667 3.240741 3.240741 2.314815 2.314815 2.314815 1.388889 1.851852 1.851852 1.388889 1.388889 1.388889 0.462963 0.925926 0.925926 0.925926 0.925926 0.925926 0.925926 0.925926 0.462963 0.462963 0.462963 0.462963 0.462963 0.462963 0.462963 0.462963 0.462963
87.700952 7.42647837 0.51164404 0.01639885 0.04989496 0.00733997 0.04468044 3.26885456 0.02328686 0.16561756 0.14744034 0.539369 0.00766138 0.00114157 0.00040294 5.1313E-05 0.01579156 0.00766138 0.00038909 5.3889E-05 0.00043188 0.00044699 0.05560705 0.00268869 0.00099598 0.00060392 0.00013307 8.6135E-05 2.9108E-05 0.00176443 0.0013347 0.00029187 0.00019963 0.00011718 4.8841E-05 4.6468E-05 4.6468E-05 1.7525E-05
95.25745 38.51248 26.32301 17.37829 15.5929 9.845695 8.403124 8.080531 7.794787 7.383132 6.778012 6.491974 4.356375 4.349855 4.349116 4.100805 3.223576 3.215445 2.74521 2.744875 2.40627 2.158325 1.659499 1.606581 1.604888 1.604496 1.604025 1.603978 1.603921 0.80371 0.803281 0.802238 0.802146 0.802063 0.801995 0.801992 0.801992 0.801964
Legend: CN= Common Name ni= Number of Individuals RD= Relative Density RF= Relative Frequency RC= Relative Cover IV= Importance Value
Table 2 Plant Species Composition of Calintaan Island, Matnog, Sorsogon Species
Oak leaf fern
Legend: CN= Common Name ni= Number of Individuals RD= Relative Density RF= Relative Frequency RC= Relative Cover IV= Importance Value
A total of 10, 143 individuals of plants was recorded from the 1 kilometer transect line that was composed of three stations measuring 300 meters each, in Calintaan Island, Matnog, Sorsogon. The study was conducted using the line intercept technique. The total number of individuals belongs to fifty-six (56) different species wherein forty-four (44) of which were identified that come from forty-one (41) genera. They came from twenty-four (24) families namely: Amaranthaceae (1), Araceae (2), Apocynaceae (1), Asteraceae (2), Combretaceae (1), Convulvolaceae (1), Cucurbitaceae (1), Cyperaceae (1), Dennstaedtiaceae (1), Euphorbiaceae (4), Fabaceae (4), Laminaceae (1), Meliaceae (1), Moraceae (4), Myrtaceae (1), Phyllanthaceae (3), Poaceae (8), Polypodiaceae (1), Rubiaceae (1), Solanoceae (1), Schizaeaceae (1), Thelypteridaceae (1), Umbelliferae (1) and Vitaceae (1). As of record, twelve (12) species were unidentified wherein one (1) species was identified up to its family level only which was under Asteraceae.
Based on table 2, Andropogon aciculatus has the most number of individuals (2452) and the densest of all plants recorded with 24.174%. Paspalum conjugatum was represented by 1388 individuals or accounted for 13.684% of all plants. Imperata cylindrica was represented by 1066 individuals or 10.509% of all individuals. While Eleusine indica has 994 individuals that constitute 9.799% of all plants recorded. It can be noted that these plant species which have the highest number of individuals and relative density belong to the Poaceae family. On the other hand, Wedelia biflora, which belongs to Asteraceae family, with 920 individuals have 9.070%. The plant species mentioned are found throughout the Philippines. In terms of the rate of occurrence, P. conjugatum occurred the most in the three stations with a relative frequency of 5.147%. It was followed by E. indica and unidentified sp. 2 with 4.779%. Coming
third were B. laevis and unidentified sp.4 with 4.044%. The species that dominated the transect line were unidentified sp. 37 (19.270%), P. conjugatum (14.670%), W. biflora (10.938%), E. indica (7.880%), I. cylindrica (7.742%) and P. paspaloides (6.846%). It is noted that all these identified species that are dominant in the three stations belong to the Poaceae family except for W. biflora. E. inidica is a very widespread species which is common in many localities and is tolerant with many disturbances. Considering this, the species was listed as least concern by the IUCN in 2011. One important tool to know the structure of the species in an area is to measure the importance value of each species. Importance value (IV) does not necessarily imply the natural significance of the organism in the community for a specific purpose but it signifies the physical structure of the community. Moreover, it gives an equal weight to relative density, relative frequency and relative dominance factors (Peyra et.al, 2011). High importance value index was manifested on P. conjugatum (33.501%), A. aciculatus (32.491%), unidentified sp. 37 (26.910%), E. indica (22.460%) and I. cylindrica (21.192%). Again, it is noted that the identified species with the highest important value come from Poaceae family. Indeed, the Poaceae, which comprised 69.377% of plant species collected, is the plant family wherein the number of individuals, relative frequency, relative density, relative dominance and importance value are relatively high. The most relative frequent species show that they were the most recurring species. Species with the most relative
density imply that they were the most prevailing. A high relative dominance indicates that the plant species have the highest area covered. Thus, high importance value signify that the plant species was the most dominant, diverse and distributed along the transect line (Biosummerians, 2010).
0.598 0.667 0.583
0.186 0.14 0.268
Shannon1 Weiner Index
2.391 2.057 0
Figure 8 Summary of Ecological indices in the Three Stations in Calintaan Island, Matnog, Sorsogon
Fig. 8 summarizes the ecological indices in the three stations. In Station 1 and 3, low Shannon-Weinner Index value resulted in high Simpson’s Index value. Using the Simpson’s range of 0 to 1 where 0 is the lowest and 1 as the highest, there is a low diversity, there is a very good chance that certain plant species dominate in the said stations. On the other hand, in Station 2 high H value yielded to low D value. Therefore, there’s a very low chance that certain plant species dominate Station 2. Then, if there’s a low D value, it will yield to a high Evenness Index and the other way around. Thus, there is a low chance for plant species to dominate a station and will result to higher species richness will be observed in the area. There were twelve (12) plant species common in the three stations. The index similarity value is 0.375. Meaning, there is a 37.5% of chance of having similar species in all the stations. There is quite a good chance
of having plant species to be present in a given area. Concluding, it’ll have low variation which is maybe due to the different human activities in the area that could’ve disturbed the vegetation cover of Calintaan Island. This primarily shows that human intervention greatly affects the species richness of an area (Peyra et.al. 2011). Conclusions and Recommendations A total of two hundred ninety-five (295) individuals of trees was recorded in Calintaan Island, Matnog, Sorsogon. The trees belong to thirty-eight (38) different species and come from thirty-four genera (34). In the characterization of species based on their relative density C. nucifera was the highest with 16.271% the said species was also highest in relative frequency with 14.814% and got 7.426% relative cover. Its importance value is 38.512%. It followed by S. negronensis with 14.237% and importance value of 26.323% and A. scholaris with 9.491% relative density. With relative frequency, coming after C. nucifera is A. scholaris with 7.870% and V. geobosa with 7.407%. P. indicus got the highest relative cover with 87.70% and importance value of 95.257 %. Coming third on relative cover is T. catappa with 3.268%. These tree species listed are notably the most sought after trees because of their great quality in lumber especially P. indicus. Station 3 was the most diverse with even tree species distribution with 2.69 and 0.884, respectively. Though, it has the lowest Simpson’s value of 0.077. It is followed by Station 1 with 2.59 ShannonWeiner value, 0.882 Evenness value and 0.087 Evenness value. Lastly, Station 2 with an H value of 2.44, e value of 0.863 and D value of 0.103.
In vegetation cover, total of 10, 143 individuals of plants was recorded from the 1 kilometer transect line that was composed of three stations measuring 300 meters each, The total number of individuals belongs to fifty-six (56) different species wherein fortyfour (44) of which were identified that come from forty-one (41) genera and twelve (12) unidentified species. A.Aciculatus was the densest with 24.174% it also got 1.83% relative frequency and 32.491% importance value. P. conjugatum got 13.684% relative density, 5.147% relative frequency, 14.670% relative cover and 33.50% importance value. I. cylindrica got 10.509% relative density. Unidentified species 37 got a relative cover and importance value of 19.270% and 26.910%, respectively. E. indica got a relative frequency of 4.799% while B. laevis and unidentified sp. 4 both got 4.044%. Station 2 had the highest diversity and evenness among the three stations with 2.391 and 0.667, respectively. But, it got the lowest Simpson’s index. Therefore, there’s a very low chance that certain plant species dominate Station 2. While on Stations 1 and 2, which got the lowest H values, there’s a good chance that certain plant species dominate the stations. Then, there is high species richness in Station 2 than in Stations 1 and 3. The Similarity Index value on arbors is 21% since there are only four species that were common in the three stations. Meaning, there is a 21% chance of seeing common species in the stations. In vegetation, there is a 37.5% of chance of having similar species in all the stations. There is quite a good chance of having plant species to be present in a given area. Concluding, it’ll have low variation which is maybe due to the different human activities in the area that could’ve disturbed the vegetation cover of Calintaan Island. This primarily shows that human intervention
greatly affects the species richness of an area (Peyra et.al. 2011). The researchers further recommend that the number of stations, number of transects/plots and sampling time should be lengthened for a more comprehensive data gathering and analysis. Moreover, other factors affecting the abundance of the trees in the area such as elevation and soil composition should be taken into consideration. The tourism arrival in Calintaan Island will surely affect the diversity of the area. As more people try to visit the island, there is more likely a chance for the area to be exploited. Both locals and tourists should be aware in the maintenance and protection of the current state of the island. References Arcega, C.V.”Status of plant biodiversity in Mt. Malarayat, Batangas, Philippines.” Asian Journal of Biodiversity. Vol. 2. 2011 Arsenio, J., Medecilo, M., Mercardo, E., Salibay, E.J., Valera, F.A.”Vegetation analysis of Mt. Maculot, Cuenca, Batangas, Philippines”. International Conference on Environment and Industrial Innovation. Vol.12. 2011 Barcelona, J.F. 2002. Philippine pteridophyte collections as a resource for conservation planning. Fern Gazette 16(6– 8): 307–312. Brewer, R. 1994. The Science of Ecology, 2nd edition. Saunders College Publishing Harcourt Brace College Publishers, USA. p. 2. Ibid . p. 296. Biosummerians. 2010. Bicol University College of Science Brown, W.H. 1919. Vegetation of Philippine mountains; the relation between the environment and physical types of
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