Societal Impact Statement: Rafflesia is the genus that contains the world's largest flowers. Despite their global appeal, most of the 42 known species are now at risk of extinction. Urgent action is needed to protect these remarkable flowers. A combined approach to conservation is recommended, including a greater level of habitat protection and support for local community action groups. Rafflesia is a suitable new icon for conservation in the Asian tropics.Summary: The genus Rafflesia, which includes the world's largest flowers, has aroused curiosity among scientists for centuries and features prominently in local culture across Southeast Asia. The plant has long been used in ethnobotanical medicine and, more recently, as a source of revenue from ecotourism. But despite its acclaim, Rafflesia remains poorly understood in many respects. Taxonomy is disputed, new species are described each year, and the plant has proven recalcitrant to cultivation. This has hindered conservation, and most of the 42 known species are now severely threatened, yet only one is listed by the International Union for Conservation of Nature (IUCN). We estimate that 60% of Rafflesia species face a severe risk of extinction (equivalent to Critically Endangered [CR]). Moreover, we predict that at least 67% of known habitats fall outside protected areas, exacerbating their vulnerability. Alarmingly, recent observations suggest taxa are still being eradicated before they are even known to science. We present recent scientific discoveries and probable extinctions and highlight case studies of conservation success, with a focus on the role of local people. We propose a multi‐pronged conservation approach combining strengthened taxonomy, ex situ propagation, ecotourism, and an extension of protected areas. We suggest action devolved to local communities and awareness campaigns linked to social media networks will be crucial outside of protected jurisdictions. Finally, we propose to establish Rafflesia as a new icon for plant conservation in the Asian tropics. A combined approach might just save some of the world's most remarkable flowers, most of which are now on the brink of being lost.
10 February 2021 in International Journal of Remote Sensing
In tropical and subtropical countries, the awareness on the importance of bamboos to the environment and economy is increasing and so is the demand for spatial bamboo information. However, mapping bamboos especially those naturally grown has been challenging, as these grasses are often mixed with other land-use and land-cover (LULC). In this study, we used Sentinel 1 and Sentinel 2 remote sensing (RS) images, and their vegetation indices to accurately map the bamboos of Iloilo province in the Philippines using: (1) pixel-based method that mapped bamboos and other LULC at 10 m resolution, and (2) fractional cover method that mapped bamboo cover at 100 m resolution (% ha−1). A random forest model was trained for each method and then validated per hectare basis using a 50:50 training-validation ratio of a stratified random sample. The fractional cover method showed 0.34 higher Nash-Sutcliffe Efficiency (NSE) and 5.10% lower Root Mean Square Error (RMSE) than the pixel-based method. Further validation within upland and lowland sites also favoured the fractional cover method, but the results of the two methods were closer in the upland site (bamboo plantation). Errors at 10 m resolution especially in the lowlands were mostly commission errors, likely because of the spectral similarity and proximity between bamboos and > 14 vegetations. Averaging the RS inputs into 100 m resulted in at most 12% separation of reflectance values among bamboos, forests, and other vegetations. Using the bamboo cover map, a total of 14,795 (± 1,283) ha bamboos and 7.45 (± 4.20) million harvestable culms (poles) were estimated for the whole province, where 54% come from the lowland. We suggest using the fractional cover method for nationwide baselining of bamboo resources.
The Southeast Asian genus Rafflesia (Rafflesiaceae) is famous for possessing the world's largest flowers. All species are rare or threatened, so understanding taxonomic diversity in the genus is crucial for informing effective conservation practice. Here we examine R. banaoana, a poorly known taxon from the remote montane rainforests of the Kalinga Province in the Philippines. This species has been treated as conspecific with R. leonardi, and overlooked in systematic studies. Using stable yet hitherto neglected features such as the stigmatic fascia surface, disk shape, process structure, annulus interior and exterior distinction, and ovary shape, we demonstrate that R. banaoana is morphologically as well as ecologically distinct from R. leonardi, and requires reinstatement at the specific rank. We present our findings in the broader context of complexity in the genus Rafflesia in the Philippines, now considered the center of diversity, with 15 species described to date. We highlight the taxonomically confused R. banaoana as a case for careful observation of previously unexamined morphological characters, as well as ecology, to avoid overlooking cryptic taxa or species complexes and to inform representative sampling in systematic treatments. Such an approach will be essential for enhancing our understanding of the diversity of this enigmatic yet poorly understood genus at a time of unprecedented anthropogenic change and species extinction. In light of our findings, we recommend a holistic approach to the conservation of Rafflesia in the Philippines.
Forest and tree cover loss decreases the ecosystem services that they may provide such as food and livelihood, protection from calamities, oxygen to breathe, and storing of carbon. This study assessed the diversity, species composition, and carbon stock potential of trees located in Aurora, Philippines. Two areas were surveyed to represent preserved and developed ecosystems. The preserved ecosystem was represented by the ultramafic forest in Baler, Aurora, whereas the developed ecosystem was represented by the urbanizing portion of Dipaculao, Aurora. The sampling site in Baler included 27,400 m2 plots and the site surveyed in Dipaculao had a total of 72.72 hectares of developed area. Results showed a higher tree diversity in Baler (H′ = 4.096) than in Dipaculao (H′ = 3.278). Species composition assessment also revealed a higher number of ecologically important species in Baler. Ecologically important species in Baler included 100% natives, 34.5% endemics, and 20.86% threatened. Dominant species in Baler were the native, endemic, and threatened Xanthostemon philippinensis Merr. and the native Teijsmanniodendron ahernianum (Merr.) Bakh. On the other hand, the developed ecosystem had 54.4% native, 4.41% endemic, and 11.76% threatened species. Dipaculao was dominated by introduced and invasive species such as Swietenia macrophylla King and Gmelina arborea Roxb. ex Sm. For the tree carbon stock assessment, a tremendous difference was found wherein the preserved ecosystem had 272.28 tons/ha carbon whereas the developed ecosystem had 16.28 tons/ha carbon. This study revealed ideal forest ecosystem characteristics in preserved forests with high diversity, the presence of many important species, and a large amount of carbon stock. This calls for immediate action from the government to continuously protect the natural forests and prioritize proper land use planning and the right choice of species to be integrated with developed areas to improve the ecosystem’s capacity to provide vital ecological services.
1 January 2016 in Journal of Environmental Science and Management
Calauit island is one of the islands in the Calamian Group of Islands in northern Palawan. The island is truly blessed with bountiful mangrove resources which provide the Tagbanuas enormous economic and ecological importance. Not known to many, Calauit island became the exit point of typhoon Yolanda causing tremendous damage to mangrove area. The study assessed the extent of damage and the recovery potential of Calauit mangrove forests from the devastation of Typhoon Yolanda. Ten sampling quadrats were established in areas where trees were observed to be 100% defoliated. Individual trees (≥ 1cm diameter) inside each quadrat were measured and evaluated based on the assessment matrix developed in this study. Results of our assessment revealed serious damage of mangroves in Calauit island. About 60% of the mangrove forests was severely affected by Typhoon Yolanda. Eight months after the typhoon, 21% of the trees have fully-recovered crown (all branches were able to develop leaves), 70% are still defoliated and 22% were already dead. Four of the 10 quadrats showed high potential for recovery as evidenced by a lot of seedlings (≥ 25 seedlings) to serve as new regenerations. Conversely, there are four quadrats without any seedling recorded. Three monitoring plots were established for continuous monitoring of the recovery of the mangrove ecosystems. A course of actions was recommended to facilitate the recovery of mangroves in Caluit island, and to bring back the economic benefits from the forest.