Introduction

Forests are storehouses of numerous plant resources that enhance the existence of local communities. These resources include timber, fuelwood, and non-timber forest products. Forests also provide ecological services such as wildlife habitat, erosion control, and climate regulations (Munasinghe 1995; Panayotou and Ashton 1995; Perrings et al. 1995; FAO 2003, 2005; UNFCC 2005).

Studying the local knowledge of the forest-dependent communities is based on the concept of human-nature interaction (Putri et al. 2014). Since the early civilization, people have cultivated plants for food, fuel, medicine, house construction materials, and traditional implements (Gerique 2006). The study on the local knowledge on plant resource use can improve the understanding of forest management at the local and regional scale (Dalle and Potvin 2004). To understand the dynamic relationship between biodiversity and social and cultural systems, ethno-ecological research has been suggested (Putri et al. 2014).

The Philippine teak forest (PTF) of Batangas Province is an example of satoyama-satoumi, a Japanese term which refers to the landscape thriving through human-nature interaction. Satoyama is a mosaic landscape composed of various ecosystems with human settlements that provide valuable ecosystem services for human well-being (Duraiappah and Nakamura 2012). The Philippines has its own share of satoyama landscapes, each having a local term of its own, such as muyong in the Cordilleras (Santiago and Buot 2018), guba in Palawan (Sopsop and Buot 2011), and lasang in the Visayas and Mindanao regions (Buot 2014).

The PTF is unique among the studied satoyama landscapes in the Philippines, as it also has a coastal ecosystem (satoumi) extending along the Verde Island Passage Marine Corridor (VIPMC), the center of marine biodiversity in the Philippines. Also known as baybay by the locals, satoumi as a landscape is intricately linked with humans for several years (Duraiappah and Nakamura 2012). Throughout this article, the authors will refer satoyama-satoumi using local terms: satoyama will be addressed as lasang (Buot 2014), and satoumi will be addressed as baybay.

There have been few studies on the local knowledge of plant resources in southern Batangas, such as the studies on timber and non-timber products in Mts. Lobo and Banoy (Caringal and Generoso 2002; Caringal and Bañados 2008), plant diversity in swidden patches (Caringal and Panganiban 2008), life cycle of Macrophysis luzona in timber wood Heritiera sylvatica (Briones 2005), underutilized edible fruits in the agroecosystem landscape of Lobo, Batangas (Cueto et al. 2015) and the pioneering account on native plants built by Loboanos for their swidden harvests (Boongaling and Macatangay 2014; Caringal et al. 2017).

The local knowledge on the Critically Endangered Philippine teak (Tectona philippinensis Benth. & Hook.f.) has never been the subject of ethnobotanical inquiry. Ethnobotany probes the local knowledge on the use of plants, which is equally valuable as the modern scientific knowledge on plant sciences. These complementary knowledge systems can be used in formulating policies and strategies in the conservation of the species and the forest ecosystem on a larger scale (Pei et al. 2009).

This research investigated the extent to which the Philippine teak is utilized in relation to other plant resources in the PTF landscape of Batangas, Philippines. This study aimed to determine the local knowledge of villagers on the uses of plants in the PTF landscape. From the information on the local knowledge, a framework for a harmonious interaction between the local community and the Philippine teak forest was established in this study.

Study Area and Methods

Study Area

The study area is located at the Philippine teak forest (PTF) in the agroscape of Batangas (Fig. 1). Forest fragmentation is visible across the landscape where the Philippine teak populations were sampled (Plot 1-24). The map shows that 2,078.39ha of forest cover was converted to farming and settlement lands from 2000-2015. The habitats of T. philippinensis were affected by this landscape process (forest cover lost in red patches) due to human disturbances. In Lobo, Batangas (Fig. 2), the Philippine teak forest fragments were in agricultural and built-up zones, mostly in the coastal hilly lands while the agroforest zone is in the interior upland villages dissecting the remaining intact forest zone at higher elevation of Mt. Lobo.

Methods

Determining local knowledge on the use of plants in the Philippine teak forest

To gather information on the knowledge on plant uses, the researchers used the Participatory Resource Appraisal (PRA). PRA is a data collection method that involves sharing of local ecological knowledge (LEK) by the local community with the researcher or facilitated by outsiders from different sectors or disciplines. The outsiders help the local community in identifying and analyzing information, practicing critical awareness, taking responsibility, and sharing their knowledge and condition to plan and act (Bhandari 2003; Macandog et al. 2014). Local ecological knowledge refers to “knowledge, practices, and beliefs regarding ecological relationships that are gained through extensive personal observation of and interaction with local ecosystems and shared among users of biodiversity resources (Charney et al. 2008; Macandog et al. 2014).”

In this study, 30 PRA participants were engaged in a half-day focused-group discussion (FGD). The researchers determined the participants based on the demographic information provided by the Municipal Agriculture and Natural Resource Office (MA/MENRO) of Lobo, Batangas. The demographic features of the participants were registered prior to the actual FGD. From this, the following outputs were generated: (1) timeline which captures the local information on significant events (biophysical and socio-economic changes) that happened in the PTF landscape and (2) resource flow of locally-important plants from the forests and agroscape into to the households or community level.

The output of PRA was supported by conducting face-to-face interviews with the key informants (KI) using a semi-structured questionnaire. The conduct of the KII was performed within a month to determine local knowledge about the ecological services of malabayabas (local name of Philippine teak) and the diverse uses of other plant resources from the Philippine teak forest landscape. Upon consent, only those persons possessing knowledge (in habitation and in practice) regarding forest plants use were interviewed purposively. Direct accounting or ocular observations were also done following the approach by Weerd et al. (2003) and by identifying the different main use categories of local plant resources (Balangcod 2010). Three main plant use categories were prioritized: (1) dwellings, especially native houses built from plant materials; (2) fuelwood; and (3) boats. House (shelter) is a primary necessity for any human beings; fuelwood for daily cooking and the boats that were built from forest plants connect the lives of the people to the sea through fishing livelihood.

Evaluating the use value index of plant resources

The use value (UV) index indicating the use reliability and relative importance of locally known plants was calculated based on the formula of Trotter and Logan (1986) and Kaval et al. (2015), and was modified as follows:

where UV refers to the use value of a species; U to the number of local citations and observed used per species; and N to the number of informants.

Establishing framework for harmonious interaction between humans and the Philippine teak forest

Based on the information gathered and synthesized from FGD and KIIs, the framework was constructed by identifying the threats and opportunities happening in the PTF landscape. Relevant conservation initiatives were done by the local community despite some drivers of change as well as institutional and political challenges in the landscape. The key actors of change in the Philippine teak forest landscape were also identified. Through systems thinking, a proposed framework relevant to the identified opportunities and challenges was proposed. This was visualized as interacting systems aiming to solve conservation challenges in the Philippine teak forest landscape.

Results

The local knowledge on the ecological services of malabayabas (Philippine teak forest), as well as the diverse plant resources utilized for building native houses and fishing boats, and fuelwood were learned from various key informants in the local community. These key informants were composed of the residents of rural upland and coastal villages of Batangas City and Lobo Batangas (Table 1).

Local Knowledge on the Ecological Services of Philippine Teak Forest

The Philippine teak, known as malabayabas or malapangit by the Loboanos (term used to identify the local people of Lobo, Batangas), was perceived well by the mountain farmers of Batangas City for its multiple ecological functions, in direct consumptive as well as indirect non-extractive values. Based on the information gathered from the interview of 57 key informants, the Philippine teak provides important wood used for building houses in the form of post or pile, lumber for roof flooring and partitions giving an overall use value index of 0.72 (Table 2). The woods of Philippine teak were also designed into furniture such as tables, chairs and tool handles; boats and propeller of galleon ships; or converted into charcoal or used as firewood. Trees were used as living peg and fence and manually trimmed lumber are used to build shed of farm animals.

Malabayabas were also grown as backyard and farm trees, as bonsai, and seedlings for planting. From the knowledge of the local people, it was revealed that Philippine teak trees enhanced microclimate and covered the hilly landscape preventing potential soil degradation. Likewise, the forest with Philippine teak provides habitat for wildlife. Taken together (Table 2), the consumptive use value of Philippine teak forest was 1.02 while all the non-consumptive use value was 0.36. This showed that the local knowledge about the multiple uses of Philippine teak and the forest in general had taken roots from the perception of community. Malabayabas is integral in the lives of local community as component wood in their dwellings and shelter for domestic farm animals (Fig. 3).

Plants Used for Native Houses

Forty-two (42) plants were known by the community as important materials for building their traditional dwellings (Table 3). The 20 most commonly used (UVIs: 0.06-1.32) species for this purpose are mulauin (Vitex parviflora), niog (Cocos nucifera), malunggayain (Melia azedarach), buri (Corypha utan), dungon (Heritiera sylvatica), dungon-pula (Planchonella obovata), guijo (Shorea guiso), amugis (Koordersiodendron pinnatum), lauan (Shorea spp.), nipa (Nypa fruticans), kogon (Imperata cylindrica), akasya (Samanea saman), manga (Mangifera indica), malaruhat-bundok (Syzygium subcaudatum), malabayabas (T. philippinensis), baguiraua (Terminalia polyantha), santol (Sandoricum koetjape), kauayan-tinik (Bambusa blumeana), malibayo (Berrya cordifolia), and yakal (Shorea stylosa).

Some non-native plants from the Philippine teak forest or other lasang ridge forests were also used by the community for building houses, such as Cocos nucifera, Mangifera indica, Gliricidia sepium, Chrysophyllum cainito, Leucaena leucocephala, and Tamarindus indica. These are cultivated plants in the agroscape from Batangas City to Lobo Batangas (Fig. 4). Samanea saman is common along the riparian zone and alluvial plain while Avicennia marina, Nauclea orientalis, Nypha fruticans, Terminalia catappa and Wrightia pubescens are coming from baybay (beach and mangrove) forests in Lobo.

The wood of molave tree, known locally as mulauin, was used primarily as pillars, flooring, stairways, tables and furniture in old houses (80 to 100 years old, Fig. 5) due to its proven hardness. Hence, the hardwood is known to be expensive as it is highly resistant to deterioration. The price of mulauin furniture ranged between PhP 30,000-50,000 in Lobo. Tectona philippinensis and Terminalia polyantha are the two most dominant hardwoods in the Philippine teak forest landscape, but these are not the primary alternative woods preferred (with UVI: 0.08) due to diminishing number of molave trees in the wild. The local community revealed other important hardwoods for building houses such as lauan, yakal and guijo (trees belonging to genus Shorea) which are harvested from Mt. Lobo, the highest lasang summit in Batangas. This mountain has its last remaining dipterocarp forests from 700-900m altitude (Caringal and Generoso, 2002; Caringal, 2008).

Plants for Firewood

According to the informants, 13 species can be used as sources of firewood. These species have use value indices ranging from 0.09 to 1.5 (Table 3). Five of those species are cultivated in lands primarily for this purpose, such as ipil-ipil (Leucaeana leucocephala), niog (Cocos nucifera), madre-cacao (Gliricidia sepium), ates (Annona squamosa), and sampalok (Tamarindus indica). Sampalok is an abundant naturalized tree growing as evergreen grove along the hills adjoining active and abandoned swiddens, ates plantation, and patches of Philippine teak trees.

Aroma (Acacia farnesiana) is a component shrub of sandy beach forest near mangroves and is identified as an excellent source of fuelwood due to its intense flammability. It is used by coastal residents as a cheaper alternative to liquefied petroleum gas (LPG). There are other incidental fuelwood species recorded from the informants, such as kauayan-tinik (Bambusa blumeana), suyak-daga (Canthium horridum), batungol (Flacourtia sp.), tan-ag (Kleinhovia hospita), and bilit (Tristira triptera).

Mulauin (Vitex parviflora) and malabayabas (T. philippinensis) are preferred less by the community to be utilized as alternative fuelwood since these woods are good materials for lumber and furniture. Meanwhile, tood (drift stump) and trimmings of mulauin, madre-cacao (Fig. 6), aroma, and dried kauayan-tinik (Bambusa blumeana) are collected by the locals from stream bank forest are often reserved as fuelwood in cooking bulk foods during social gatherings such as birthdays, family reunions, fiestas, weddings, and Christmas celebrations.

Plants for Wooden Boats

The long coastline from Batangas City to Lobo to San Juan, Batangas along the Verde Island Passage Marine Corridor (VIPMC) is a well-known fishing ground. In Lobo alone, there were 730 registered bancas; 592 of which were motorized and 137 are small non-motorized used for fishing (MA-LGU Boat-R List, 2016). The Loboano fisherfolks (among the FGD/KIIs participants) revealed some 11 plant names that are locally harvested from the ridge to coastal woodlands in Lobo. These plants, popularly used as poles, are purchased from landowners and then brought to a lone local boatbuilder in lagadlarin (meaning: lagarian or lumberyard — a village near Lobo River where during the Spanish conquest of Batangas, the forest logs harvested from the mountains were rafted and sawn before rafting again to the other side of the river — in a modern-day village; Fabrica — a small port in Lobo where boats were built).

The most commonly used plants (UVI: 0.08-2.27) for building small wooden boats (Table 3 & Fig. 7) were the lauans (Shorea spp.), kauayan-tinik (B. blumeana), himbabao (Broussonetia luzonica), yemane (Gmelina arborea), guijo (Shorea guiso), mulauin(Vitex parviflora), santol (Sandoricum koetjape), anonang (Cordia dichotoma), kamatsile (Pithecelobium dulce), malibayo(Berrya cordifolia), dungon (Heritiera sylvatica).

Except for guijo and the lauan (lauan pula and puti — red and white lauan as revealed by the community) — the rest of the mentioned plants are still abundant in Lobo. Raw materials such as kauayan-tinik were used as katig (balancer or floater pole) for all boats, which can be shared by landowners at a very affordable price of Php 100-150. The guijo and the lauan are imported and rafted to Lobo by big motorboats from Mayagao, Baco, Oriental Mindoro. These dipterocarps woods — light, floaters, and easy to uplift — are used in certain parts of the boat called batiula, kasko, and roda. Accordingly, the woods of dungon, malabayabas and mulauin should not be used in large proportion due to their inherent heaviness, hence the boat will sink during fishing. Specifically, the inner woods of T. philippinensis can easily absorb water and this will not become heavy-duty for long time fishing.

Based on the local ecological knowledge of Loboanos, the Philippine teak forest (or malabayabas) is one of their important forest resources (Fig. 8). From the 1940s to the latter part of the 1990s, the landscape used to contain abundant forest resources — a mosaic of different natural vegetation matrixes (NVMs) such as beach, mangroves, bamboos, dipterocarps, dungon, mulauin, peat, century palm, and kalumpit. All these resources are becoming moderate to minimal and diminishing in the present time (Fig. 8).

Loboanos also learned that the diminishing forest resources are caused by increasing population, road infrastructure, and conversion of forest lands into farming ates, coconuts, bananas, vegetables and root crops (Fig. 9). During the 1940s to early 1980s, where the human population in the area were few, the forests were their source of woods for housing and fuel. There were also abundant foods caught from the river, stream and the sea. Flooding events were uncommon. The river was known to be clear with a deep channel. Today, they experience extreme flooding as their waters are silted. By then, the dry and wet season comes normally. In recent times, shorter but extreme wet seasons and longer dry seasons can be observed, resulting in moderate to minimal harvests in their farms. Moreover, in the Batangas City side, it was reported that land use has changed remarkably. From 1946 to 1981, the former agricultural land rapidly developed into major urban centers. From 1981 up to the present time, the land has been transforming into major urban commercial and industrial centers. The area allocated for ecological development comprised only 389.86ha (1.41%) for forests and while a large proportion, 5,584.37ha (20.21%) for agriculture. Marginal forest lands can be found mostly in villages at lower slopes of Mt. Banoy along the boundary line with the municipality of Lobo (Batangas City Zoning Division-OCPDC, 2017).

Discussion

The Philippine Teak Forest and people in the lasang-baybay landscape: A framework for a harmonious interaction

Knowing the importance of the Philippine teak forest to the humans of Batangas province (Table 2, Figs. 3-7), there is a need to design a framework for harmonious interaction between the two opposing sectors of this lasang-baybay forests and agroscape. In the early times, when human populations were low, the relationship was somewhat mutualistic. The forest resources, the coastal resources, and the villagers were one. However, with the recent population explosion, this has not been the case anymore. Resources are dominated by humans, as in the case of so many satoyama (lasang) and satoumi (baybay) throughout the world.

Results in this study illustrated a diminishing trend towards the depletion of biodiversity resources (Figs. 1, 8 and 9), causing potential local extinction of various plant resources and loss of ecological services from the PTF landscape. Thus, the authors proposed a conservation framework, as shown in Figure 10. This was constructed through systems thinking, illustrating the synergy of the conservation roles of various stakeholders or actors (subsystems): (1) the policy and regulating institutions (e.g.DENR, PGENRO, LGUs), (2) private institutions and individuals, research and educational institutions (e.g. BatStateU, UPLB, and other HEIs), and most importantly, (3) the local communities as important conservation allies. The framework also shows the anthropocentric drivers that can have impacts on the PTF. These pressures, together with the actors can influence the state of the PTF.

At the bottom of this framework (Fig. 10), the in situ and ex situ conservation efforts are listed in the species and landscape levels. These varying efforts are mainly localized, allowing the subsystems to be involved in conservation efforts firsthand. At the local level, there were already identified conservation initiatives that must be supported continuously to perpetuate the intergenerational ecological services of the Philippine teak and other plant resources. Integrating these approaches will harmonize the interaction among the ecosystem and human actors towards the conservation of PTF.

The outputs of the analysis on the local ecological knowledge show that the Philippine teak forest was one of the mosaics of locally valuable resource types in Batangas Province. Unfortunately, urbanization, infrastructure development, and agricultural expansion have affected these resource base and pose major challenges for reconciliation ecology.

Given today’s continuing fragmentation resulting in patchy occurrences of T. philippinensis, there are still local practices that may serve as practical models of human-forest interaction. The existence of the Philippine teak forests within the agricultural zone from ridges to coast shows the ecological integration of this forest in the lasang-baybay landscape. Reconciliation ecology should not only save the threatened species in the landscape level; it should also nurture existing socio-ecological interaction outside (ex situ) the remaining area where there are humans, i.e. Philippine teak trees associated with swidden patches, forage plantations, native pineapple plantations, grazing patch, rice paddies, in backyard woodlots, near sports facility, along village roadside, and in beach resorts. These are some evidences showing that the Philippine teak, apart from its dry wildland habitat can co-exist with the caring local humanity. The members of the local community are important social allies that must be tapped for long-term conservation programs.

In the proposed framework (Fig. 10), understanding the local drivers of threats to the PTF will allow the policy, regulatory, and research institutions to address these challenges and do restoration efforts for both the species level and forest ecosystem. According to Adams et al. (2016), conservation approaches can be highly varied but localized, building from local knowledge, stakeholder values and peculiarities of natural systems. While there is competition for resource use by anthropocentric players and ecocentric conservation practitioners (Burkhard et al., 2012), the policy and regulatory approaches and solution-based science still play an essential role for effective policy development, decision-making and implementation of conservation actions (Adams et al., 2016).

Conclusion and Recommendations

The local community has valuable knowledge about the diverse plant resources, not only from the Philippine teak forest but also from the lasang-baybay (satoyama-satoumi) landscape. Cultivated plants are the best alternatives to sustained exploitation of some indigenous ones (mulauin and malabayabas) that are used for essential livelihoods and material necessities of the local population. Since the old times, molave trees have been used to build houses, as seen in the century-old dwellings, suggesting the earlier cause of its dwindling abundance in the wild until the present time. This could be the reason for the dominance of T. philippinensis in a limestone habitat in Lobo, Batangas, where V. parviflora is expected naturally to have overlapped. As soon as other plant resources in the landscape are exhausted for dwellings, firewood and boat makings, anticipated misuse of other locally lesser-preferred species (T. philippinensis and Terminalia polyantha) is expected soon. Hence, there is a need for the local community to be given institutional encouragement to preserve natural patches of native plants from the ridge to coast, and at the same time, continue integrating the indigenous flora in their farms and homegardens for posterity use values.

As Janzen (1988) puts it to address ecological restoration of the tropical dry forest: “The frontier is gone. The audience is local. The power is local. In the near future, almost all members of tropical societies living on dry forest soils will be settled on firmly titled land and will be leading a real or vicarious urban life with amenities such as good roads. Survival of a wildland will depend on regional policy decisions by government institutions and planning commissions, and those decisions will be made in conjunction with the local community”.

Acknowledgements

This research is part of the PhD Dissertation of the first author. The authors would like to thank the following: (1) Department of Science and Technology Science Education Institute (DOST-SEI) for providing financial assistance for the conduct of this study through the Accelerated Science and Technology Human Resource Development Program — National Science Consortium (ASTHRDP-NSC); (2) University of the Philippines Los Baños School of Environmental Science and Management (UPLB-SESAM) and (3) Batangas State University (BatStateU) for providing facilities for the authors; (4) the Municipal Government of Lobo, Batangas for their assistance in the logistics of the conduct of FGD and KII; and (5) the Municipal Planning and Development Office (MPDO) of Lobo, Batangas and providing the CLUP map of Lobo, Batangas.

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