Plant Diversity and Status in the Northern Landscape of Mt. Malindang Range and Environs, Misamis Occidental, Philippines
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Training –Workshop on Taxonomic Techniques A training on taxonomic techniques was conducted to teach local researchers inventory techniques, grouping of plants by habit (tree, shrub, herb and vine) and taxonomic grouping (bryophytes, lichens, ferns and fern allies, gymnosperms and angiosperms). The participants were also taught proper documentation, collection and pressing of specimens for herbarium vouchers gained from the training with the laborers. Results and Discussion Vegetation Types and Plant Communities Mt. Malindang Natural Park, with a total surface area of 53,262 hectares, has been a protected area since 2002. The remaining forest, covering approximately 33,000 ha, is still a natural tropical rain forest. The forest covers the higher portion of the mountain (up to 2,475m) and the steep slopes at lower altitudes. The forested area declined dramatically during the last decades). Analyses of maps and satellite images revealed that forest decline still continued especially on the more accessible sites. The decline was attributed to rampant shifting cultivation. Plant Communities Classification of 87 relevees of the forest area showed two different groups of vegetation types which had only few species in common. The first group comprised mossy forests and montane forests, both above 1,400 m above sea level (asl). The second group was that of forest communities occurring below 1,400 m asl (Table 5). This included the submontane forests (almaciga and dipterocarp), colline (mixed dipterocarp and plantation forests) and lowland (lowland dipterocarp, and lowland mixed dipterocarp forests (Table 6 and Figure 5). The colline and lowland forests were fragmented and occurred predominantly on steep slopes and were not accessible for farming. Aside from forests area, there was an arable area located at 1,400 m asl, below the agro ecosystem (Table 6). This was planted with vegetables, cereals, and agro forestry species; but a larger portion was permanently occupied by grass-dominated fallowed areas. Mossy and Montane Forests The mossy and montane forests had severasl species in common, the most frequent of which were Plagiogyria pycnophylla, Elaeocarpus sp., Mastixia trichotoma var. clareana and Macaranga dipterocarpifolia. The last species was also present in forests at lower altitude. A group of species occurred both in the montane forest and on the southern slopes of the mossy forest. Examples of these were Lithocarpus philippinensis, Polyosma philippinensis, and Racophyllum spectabile. Many species had adapted to high zones in the mountain, except the northern slopes with higher altitude. This also applied to species that appeared only on southern slopes in both forest types, e.g., Cinnamomum mercadoi and Meteoriopsis squarrosa. Mossy Forest: Ascarina philippinensis- Xanthomyrtus diplycosiifolia Community Diagnostic Species Aside from Ascarina philippinensis and Xanthomyrtus diplycosiifolia, the community was characterized by four additional species, namely: Ilex sp., and Dacrycarpus cumingii. The latter two species were present in the montane forest at lower density. Structure and Vegetation Profile The mossy forest was characterized by the presence of small trees with proproots and aerial roots coming out from one to a few meters from the base of irregularly shaped tree trunks. The presence of proproots indicated the adaptation of trees to step slopes, which was prevalent in this zone. The proproots seek new resources of nutrients in crevices and the aerial roots give extra support to the growing tree. As in other mossy forests in the Philippines, the trees were dwarfed and their trunks gnarled, especially those that grew near the mountain peak, due to strong wind pressure. Compared with those in montane forests, the trees were shorter by 10 to 20 m. The tree layer was also relatively denser (75% to 85% cover). The canopy layer was composed of the two dominant plant species. The branches and trunks of trees and the forest floor were largely covered with mosses, thus the name mossy forest. Subdivision The Ascarina philippinensis – Xanthomyrtus diplycosiifolia community was divided into two variants, according to slope aspect. The variant on the southern slope was richer in species and contained more endemics. Among the differential species (not found in forests on the northern slopes) present were three species of mosses: Aerobryum subpolytrichum; an endemic tree: Dacrydium elatum. Floristic diversity The number of plant species per plot varied. The communities on the north-facing slopes had lower species richness (21 per plot), compared with the south-facing slopes (more than 30 species per plot). The number of endemic species recorded for these slopes were five and nine, respectively (Table 7 and Figure 6). It had a diversity index of 1.85). A total of 256 species had been recorded in this community, from which more than 50% belonged to ferns (pteridphytes) and mosses (bryophytes), plants typically adapted to grow in moist places. This forest type was characterized by high plant diversity: high species richness and endemism, many of which were economically important species. The number of threatened species was relatively low. Ecology The mossy forest, usually found at altitudes ranging from 1,700 to 2,450 m asl, is also known as the cloud belt, due to the persistence of clouds (Brown 1919). Relative moisture and rainfall are highest compared to other forest ecosystems. Due to the high precipitation and leaching, soils are usually acidic (pH 4.6-5.1). The Slopes can go as steep as 75 degrees. Distribution The Ascarina Philippinensis – Xanthomyrtus diplycosiifolia community was observed in Mt. Peak Tandayan and Mt. Ginlajan in Barangay Lake Dumingat, Don Victoriano, Misamis Occidental. Mt. Peak Tandayan, or commonly referred to as “North Peak”, is also a mossy forest (zonal forest type above 1,700 m) and covers almost the entire area in the altitudinal belt. Land Use The mossy forest stabilized the hydrological regime and local microclimate, and protected the soil from erosion. It also provided the local people food and medicines (from plants and animals) that were scarce or unavailable in the lowland. The average number of species that provided nontimber forest products was 11 per plot. The mossy forest remained relatively intact, except in the mountain peaks where the ground cover vegetation was damaged due to trampling of occasional campers. Selected sites in the mossy forest of Mt. Ginlajan also remained intact because they were considered scared and used by the Subanons for religious ceremonies. Montane Forest: Clethra canescens var. novoguineensis – Impatiens montalbanica Community Diagnostic Species The Clethra canescens var. novoguineensis – Impatiens montalbanica community was characterized by 10 tree species restricted to this forest type. Some of them were Clethra canescens var. novoguineensis, Ficus glanddulifera, Ficus septica, and Melicope confuse. Although these species differentiate the montane forest from the mossy, they may also occur at low densities in the mixed dipterocarpforest at lower altitudes. Among the typical and frequent herbaceous species of this community were Impatiens montalbanica, Marattia sylvatica, and Trichomanes pallidum. However, Lithocarpus philippinensis and Macaranga dipterocarpifolia were the two most dominant tree species. Structure and Tree Profile The montane forest was characterized by trees taller (on the average) than those observed in the mossy forest. The height of the tree layer was from 30 to 35 m and with 90% species crown cover. Trees with big trunks were also found here. Lithocarpus philippinensis, L.mindanaensis, and Mastixia trichotoma var. clarkeana were endemic species that had the largest canopy cover. The shrub layer did not grow more than 5 m and with 10 to 15% cover. The moss layer was less conspicuous than in the mossy forest. Subdivision Just like the mossy forest, the montane forest community was divided in two variants: a species-rich variant on the south-facing slopes and a floristically less developed variant on the north-facing slopes. A group of about 20 species characterized the south slope variant though individual plant presence was relatively low. The diagnostic feature of the south variant group was its lower number of species and lesser density. Floristic Diversity The communities on the north-facing slopes were less abundant in species (24 per plot), than on the south-facing slopes: 29 species per plot. The number of endemic species was very high on both slopes, with 10 species on the average. Only the almaciga forest, which occurred only in small patches, contained the highest number of species and endemics (Table 7 and Figure 6). In total, 263 species have been recorded from the plots in the montane forest; nearly 50 percent of the extra were ferns (pteridophytes) and mosses (bryophytes), both plant groups that prefer dark and moist places. This vegetation had a very high plant diversity based on species richness and endemism (Figure 6) and with a diversity value f H’=2.0, it was considered the highest among vegetation type. Ecology The montane forest was situated at an altitude of 1,400 to 1,700 m asl. Relative moisture and rainfall were also high in these parts. The slopes were considerably less steep than in the mossy forest with an average of 30o as compared to 60o in the mossy forest. Soil pH in the montane forest was somewhat higher, indicating that they are less acidic. Distribution The communities were observed in Mt. Ulohan sa Dapitan in Barangay Lake Duminagat and Mt Pungol in Barangay Gandawan. Land Use Since the lowland forests had mostly disappeared, the lower montane forest became the most important source of nontimber forest products such as wild food plants, firewood, building materials, round wood of economically important species was higher in the montane forest than elsewhere because lower slopes of the forest product (NTFP)Species were found on both the south-facing and north-facing slopes. Almaciga Forest: Agathis philippinensis- Cinnamomum mercadoi Community Diagnostic Species The almaciga forest was the best identified plant community of Mt. Malindang due to the presence of large number of characteristic species, many of which were endemic and threatened. Samples of these were: the constant character species Agathis philippinensis, Cinnamomum mercadoi, and Ziziphus angustifolius. Structure and Tree Profile The almaciga forest was characterized by 90% dominance of the tree species Almaciga philippinensis, the largest (180-230 cm in diameter) and the tallest (35 to 45 m in height). Although threatened and endemic, it had the highest canopy cover. Another frequent species was Syzygium sp. The herb layer covered 50 to 60% of the forest. The shrub layer was patchy, covering only 5% and did not grow higher than 3m. Floristic Diversity Communities of these forests were the most rich in species (33 per plot) compared to all the other forest types in Mt. Malindang).They occurred only in small patches. The number of endemic and threatened species was on the average 13 and 6, respectively. A total of 157 plant specie were recorded in the plots, dominated by flowering plants (angiosperms), 50% of the taxa were identified as ferns (pteridophytes) and less were mosses (bryophytes). The forest had a high diversity value of 1.97 and extremely high plant diversity based on species richness, endemism and threatened species as compared to the other forest vegetation types Ecology This submontane forest was found between 1,200-1,400 m asl. The moisture and rainfall were relatively high. The slopes (200 on average) were less steep as a compared with the submontane dipterocarp and lowland forests, with slopes of almost 50 and 65 degrees respectively. It also occurred on different rock types: andesite, porphyritic andesite and scoria. Soil pH was low or acidic: averaging 4.7; soil texture was that of clay loam, which explained the high moisture content. Distribution This community was observed in the southeastern side of Barangay Sebucal. Land Use Almaciga forest was an important source of NTFP such as building g materials, firewood and most importantly, resins from the break of Agathis philippinensis. This forest helped in protecting the soil from erosion and stabilized the local microclimate which had a high biomass. However, because of their accessibility t the local communities, the forests were greatly threatened. Cutting of old growth almaciga for house construction and heavy collection of resins from the trunks were observed. Submontane Dipterocarp Forest: Ficus minanhassae – Bischofia Community Diagnostic Species The Ficus minahassae- Bischofia community in submontane dipterocarp forest (Table 5) was characterized not only by the abundant presence of Ficus minahassae and Bischofia, but by many other species, most of them in low presence. This forest was also strongly differentiated against almaciga forests by Shorea polysperma (threatened, endemic and economic). Constant species found were Shorea polita, meliosma sp., Palaquium luzoniense (threatened, endemic and economic), and Vavaea amicorum, all which occurred also in almaciga forests and some (Shorea mindanaensis and meliosma sp.) in colline forests. The community contained a large number of character species; may NTFP species and endemic plants were also observed. Structure and Tree profile The forest type distinct layers: a canopy layer consisting of tall trees with big buttresses like Shorea polysperma, S. mindanaensis, and Ficus sp., covering 60-75%. The buttresses extended to about a meter from the tree and its function was to support it. The other layers were made up of smaller trees, shrubs, climbing bamboos, palms, vines and several species of Freycinetia twining around the tree branches. Floristic Diversity The communities of the submontane dipterocarp forests were also very rich in species at 28 per plot. The number of endemic and that of threatened species were high as well, with eight and six species on the average, respectively; with a diversity value of 1.91. A total of 219 plant species was recorded in the plots, dominated by flowering plants or angiosperms. The number of ferns (pteridophytes, 20%) and that of mosses (bryophytes) were considerably lower than in the forests of higher altitudinal belts. Ecology The submontane forest was found at an altitude ranging from 900 to 1,100 m asl. Moisture and rainfall in this kind of forest were not as high as in the other forest communities described above. The community thrived on very steep slopes, with a 50-degree average, with sandy loam soil and andesite type of rocks. Soil pH averaged 6, which was less acidic than in the almaciga forests. Distribution This forest was observed only in Mt. Capole in Barangay Sebucal, Oroquieta City. Land Use The submontane dipterocarp forest was an important source of forest products such as food, firewood, building materials, timber and medicines for the local people. In addition, the dipterocarp forest stabilizes the hydrological regime, protects soil from erosion and stabilizes the local microclimate in the forest. The lower parts of the submontane dipterocarp forests had been logged in the past and/or converted to other land uses such as agricultural fields and plantations. Lowland Dipterocarp Forest: Ficus variegata- Selaginella moellendorfii Community Diagnostic Species The lowland dipterocarp forest was characterized by a group of 12 species, which occurred in low presence, e.g., Ficus variegata, Selaginella moellendorfii, the endemic Macaranga grandifolia, and the threatened Toona calantas. The community was less rich in species (20 per plot) and endemics compared to the montane dipterocarp forests. The presence of pioneering trees such as Ficus variegata and Macaranga grandifolia indicate a disturbed (early middle stage secondary forest) habitat. Important constant tree species in this community were: Knema glomerata, Shorea contorta and Shorea polita, all endemic, threatened, and of economic importance. Structure and Vegetation Profile This forest was characterized by tall dipterocarp trees, which also occurred in the submontane dipterocarp forests. This tree layer of 20-25 m high covers about 60%. Floristic Diversity The number of plant species in the communities of the lowland dipterocarp forests was relatively low. This applies also to the endemism score . A total of 144 plant species were recorded in the plots with diversity value of 1.87. Ecology The lowland dipterocarp forests were a secondary forest type. Its stands occurred in patches located at altitudes ranging from 229 to 500 m asl. Moisture and rainfall were less than in the submontane dipterocarp forest. Both forests types on slopes adjacent to the Layawan River. The slope where the lowland forest was found was less steep than that of other forest types (25 degrees average) and the soil consisted mainly of sandy loam. Soil pH was moderately acidic (5.5 average), which was approximately equal to the pH in the submontane dipterocarp forest. Distribution This forest was observed in Barangay Mialen, Oroquieta City and Barangay Mamalad, calamba, Misamis Occidental. Land Use The secondary forest type was found in patches as a result of logging. Kaingin and shifting cultivation further reduced the area occupied by the forest community. In addition, forest products such as firewood, building materials and timber were continuously extracted from the forest causing the deterioration of the remaining habitat. Mixed Dipterocarp Forest: Syzygium- Sticherus laevigata Community Diagnostic Species The mixed dipterocarp forest in the Mt. Malindang area was represented by the Syzygium- Sticherus laevigata community. This community was typified by a large group of more than 20 character species, from which Syzygium was constant. A threatened endemic species within this group was Artocapus blancoi. The shrub, Hydrangea scandens ssp. Chinensis was also observed at higher altitudes in the montane forest with low presence. Shorea palosapis, an endemic and threatened tree species, was constant in the community, but also occurred at a lower presence in the lowland dipterocarp forest. Species richness was more or less equal to the lowland dipterocarp forest: 19 per plot. Many trees within this community were NTFP species. Structure and Vegetation Profile The mixed dipterocarp forests were found as the remaining patches of the original forest (Figure 6). The trees had buttresses and produced proproots for support, an adaptation feature of plants growing on steep slopes. The growth form was characteristic of Syzygium. The height if the tree layer ranged from 25 to 30 m, covering about 70%. The canopy species included: Lithocarpus sp., Shorea palosapis (threatened and endemic), and Caryota cumingii (endemic). The herb layer species with high presence was a fern Sticherus laevigata which usually grow in open areas. With its long creeping rhizomes and extensive roots system, it can be useful in preventing soil erosion. Floristic Diversity The diversity if this forest community was more or less the same as that of the lowland dipterocarp forest. The colline forest plots contained a total of 181 recorded plant species. The number of threatened species was high (three species), and the number of endemic species was moderate. The ferns and the other herbaceous plants were less represented in this community. Ecology This forest type is located at an altitude ranging from 450 to 900 m asl. The moisture and rainfall were less compared to the other forest types. The slopes were quite steep: 40 degrees on the average. The soil consisted of sandy loam. Soil pH was acidic (averaging 4.5) Distribution This forest is observed in Barangay Peniel, Lopez Jaena and Barangay Mamalad, Calamba, Misamis Occidental. Land Use The forest is found in patches due to logging. It may be expected that the continuous cutting down of trees for firewood, building materials and wood timber in the remaining forest will further reduce the area. Cultivation in this forest was not possible due to its steep slopes. Lowland Mixed Dipterocarp Forest: Diplodiscus paniculatus- Lithocarpus spp. Community Diagnostic Species Lowland forest on steep slopes was assigned to the Diplodiscus paniculatus- Lithocarpus sp. Community. Species richness was relatively low compared to other colline forests (16 per plot. The group of character species represents mainly trees, which are classified as NTFP species and one endemic palm species (Caryota cumingii). Structure and Vegetation Profile This community was observed as patches of remnant natural forest with a low tree layer (height of 20 to 25 m), covering about 55-66%. The canopy species observed were Lithocarpus spp. And Shorea sp. Lygodium auriculatum and Homalomena philippinensis were dominant in the herb layer. Floristic Diversity Species richness was relatively low compared to other dipterocarp forests; this is reflected in a low diversity value of 1.56. A total of 97 plant species in the plots were recorded. The low species richness and diversity may be due to the steepness of the area. Ecology This lowland forest type was located at an altitude ranging from 220 to 450 m asl. The recorded moisture and rainfall were less than in the other forest communities. The slopes were very steep, 65 degrees on the average, and rocky since the parent since the parent material was mainly sandy loam. Distribution The forest was observed in Barangay Toliyok, Oroquieta City. Land Use Only remaining patches were observed on very steep, impracticable slopes. Shifting cultivation and cutting down of tree (for firewood, building materials and timber) were observed in less steep areas. Plantation and Degraded Forests Diagnostic Species Plantation and degraded forests were characterized by cultivated trees like Acacia Mangium and Cocos nucifera, and weeds, e.g., Imperata cylindrica and Chromolaena odorata. This community obtained the lowest species richness (11 per plot) of all forests types . Structure and Vegetation Profile The plantation forest was characterized by a tree layer of planted species which were 15 to 20 m tall, covering 75 to 85%. The forest floor was covered by Imperata cylindrica and Paspalum conjugatum. Floristic Diversity Plantations had the lowest species richness compared to the other forest types. A total of 61 plant species were recorded in the plots, from which only 30% were trees and 50% were herbs species. This vegetation type had the lowest plant diversity based on species richness and endemism. Compared with the other vegetation types, it also obtained the lowest diversity value of 1.52. Ecology Plantation forests were found at an altitude ranging from 120 to 900 m asl with low rainfall. The slope was 30 degrees on average. Soil pH was acidic (averaging 4.5) |