Rapid Assessment of Plant Diversity in Ultramafic Soil Environments in Zambales and Surigao del Norte, Philippines

Abstract

This study covers the vegetation composition and diversity in two heavy metal sites with distinct climatic and edaphic environments in the Philippines, Zambales, and Surigao del Norte in the northern and southern regions, respectively, Tree density and basal area were higher in Zambales than in Surigao del Norte. Species diversity, however, was higher in Surigao del Norte site (H'=1.1071) than in Zambales, which may be attributed to high water and nutrient availability and unique geologic formations. Soil properties also varied, with higher organic matter concentration in Surigao del Norte. Twenty-one out of 35 taxonomic families in both sites were common in serpentine soils. Nine families were recorded to have a large number of individuals on both sites. A total of 11 species were known metallophytes of which four are Ni hyperaccumulators and seven are endemic to both sites. These Ni hyperaccumulators have a high potential for phytoremediation, phytostabilization, and rhizofiltration. However, due to the scarce information on Ni hyperaccumulators, conservation statuses of most of them are unknown. Agricultural interference, site destruction and excessive mining are some of the factors contributing to the diminishing fate of metallophytes. Thus, it calls for its prioritization in biodiversity conservation.

Short Communication: New distributional record of Phyllanthus securinegoides Merr. (Phyllanthaceae) and Rinorea niccolifera Fernando (Violaceae) of Homonhon Island, Philippines

“…The two metallophytes are Rinorea niccolifera Fernando and Phyllanthus securinegoides Merr., which are often seen and documented in the islands of Luzon and Mindanao (Merrill 1912;Fernando et al 2013Fernando et al , 2014Quimado et al 2015;Ata et al 2016) (Table 1). Our study revealed a new distributional record of metallophyte species found in the barangays of Casuguran and Habag, of Homonhon Island, Philippines.…”

Floristic study of an ultramafic formation in Sitio Magarwak, Sta. Lourdes, Puerto Princesa City, Palawan Island, Philippines

“…Pulgar, Mount Bloomfield and Mt. Victoria Range as well as other parts of the country (Reeves 1992;Proctor 2003;Fernando et al 2008;Amoroso et al 2009;Van der Ent 2015;Aribal et al 2016;Ata et al 2016;Lillo et al 2018;Ocon et al 2018;Sarmiento 2020). In particular, the presence of species such as Xanthostemon speciosus Merr., Scaevola micrantha C. Presl, and Brackenridgea palustris ssp.…”

“…Likewise, Evenness (E) Index for overstorey (0.885) and ground cover (0.840) concur with the results of the other diversity indices giving an overall impression that ultramafic soil is highly productive and stable. However, it should be pointed out that there is an array of factors that influence diversity in an ultramafic environment (Ata et al 2016). Soil chemistry, particularly soil pH and organic matter content has been considered as the most critical factor for the survival of the vegetation in the ultramafic forest.…”

“…In addition, geologic events related to the formation of an ultramafic also accounts for the difference in the diversity of ultramafic formations. A comparison of species diversity in ultramafic forest of Zambales and Surigao del Norte noted the difference in the species composition which was partly attributed to the ultramafic complexes' ages and possible lithospheric sources (Ata et al 2016). Ultramafic formations regardless of location may share a distinct suite of chemical and physical features but tropical ultramafic soils are unique in elemental content, moisture, organic matter content, and soil pedology (Lewis andBradfield.…”

“…Further works confirmed that this is due to low nutrient availability, high Mg/Ca quotients, nickel and manganese toxicity, inadequate water supply, and frequent fire occurrences (Proctor 2000a, Proctor 2003. Consequently, this initial efforts inspired more botanical explorations that resulted in the documentation of more ultramafic environments in the various parts of the country (Amoroso et al 2009;Claveria et al 2010;Fernando et al 2013;Fernando et al 2014;Aribal et al 2016;Ata et al 2016;Sarmiento and Demetillo 2017;Lillo et al 2018;Ocon et al 2018;Agoo and Evardone 2020;Sarmiento 2020). These local efforts confirmed the presence of distinctively stunted vegetation and the high degree of endemicity of ultramafics which also led to the discovery of new hyperaccumulator plants most of which are associated with nickel.…”