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Tree phenology from Lanjak Entimau Wildlife Sanctuary (Sarawak, Malaysia) October 2016-January 2020

Citation

Cosby, Olivia (2022), Tree phenology from Lanjak Entimau Wildlife Sanctuary (Sarawak, Malaysia) October 2016-January 2020, Dryad, Dataset, https://doi.org/10.5061/dryad.n8pk0p2x3

Abstract

Community-managed forests (CF) bordering protected areas are critical to conservation in Borneo. Iban-managed CF retain tree species characteristic of primary forests within pulau, remnant old growth forests conserved for harvesting forest products. However, the selective felling of large trees, and proximity to surrounding mixed-use mosaic habitat, likely influence pulau structure and composition. Tropical Asian forests exhibit supra-annual mast fruiting (3-7 yrs) and extended periods of fruit scarcity, but fruit trees encouraged and planted by communities, in mixed-use mosaic bordering pulau, may benefit wildlife during periods of food scarcity.

This data was used to investigate the seasonal availability of foods (fruits and seeds) important to wildlife within protected forest (predominately primary mixed-dipterocarp forest) and community-managed Iban pulau (selectively logged primary forest remnants) at the boundary of the Lanjak Entimau Wildlife Sanctuary (LEWS), in Sarawak, Malaysia (Borneo). We documented the presence of fruits and seeds, comparing relative composition and fruiting activity between forests, using bimonthly phenology surveys across 50 locations (October 2016-2019). We also documented fruit presence along walking transects within LEWS and the mixed-use mosaic bordering pulau within Iban territories.

Methods

This study was conducted using forest plots established within and adjacent to Lanjak Entimau Wildlife Sanctuary (LEW) in Sarawak, Malaysia (a portion of Borneo) (111°53'E to 112°281'E and 1°19'N to 1°51'N). In October 2016, we established 40 research plots within the sanctuary’s protected forest (PF) and within the Iban managed pulau (CF pulau). Plot selection was subject to accessibility, minimum spacing between plots, and presence of fruit trees (wild unplanted). We defined fruit trees as any tree that produces fruits or seeds eaten by mammals or birds, whether fleshy or hard, excluding trees with toxic properties. We also excluded trees that produce small seeds, or berries, of a size eaten mostly by small birds or rodents, as these would be overly challenging to detect through visual surveys. Over subsequent trips (February 2017, November 2017, and January 2018), our team established 10 additional plots to increase sampling effort. All plots were ≥20 m from the forest edge and 350-500 m from all other plots. Within each plot, we tagged every fruit tree ≥10 cm in diameter at breast height (DBH) within a 20 m radius. DBH of each tagged tree were recorded and leaf specimens were collected for species identification. Over subsequent surveys, additional specimens of fruits and flowers were collected to further improve species identification. Once established, each plot was divided into quarters, patches of dense vegetation and the relative spacing of trees was sketched, and our botany team qualitatively assessed the understory density. The understory of a plot was categorized based on this qualitative assessment as: “dense”, “medium”, or “open”. Of 50 research plots, 29 were within the PF and 21 within the CF pulau. All forest plots within the CF pulau were bordered by a mixed-use mosaic. Starting in our second year of surveys (November 2017), we divided regularly-used trails between plots into transects (350-500 m stretch of forest per transect) to compare availability of fruits and seeds in areas between PF plots to those within the CF mixed-use mosaic. We monitored plots every two months for three years (October 2016-January 2020). On each bi-monthly visit, we stood at the base of each tagged tree and visually surveyed for fruits-on-the- ground and, with binoculars, presence of flowers, young fruits, and mature fruits within the canopy. From November 2017-October 2019, field teams also recorded presence of flowers, young fruits, and mature fruits (ground or canopy), along select trails between plots. Photographs and voucher specimens, collected from plots and along the transects, were sent to local botanists at the Sarawak Herbarium for species confirmation using the most up-to-date sources for identification and nomenclature.

Usage Notes

Datasets:

1) phenology_treeplots_LEWS: Comparison of LEWS forest (PF) vs. community forest plots (CF) (aka protected forest vs. Iban pulau) represented by tagged trees in fruit tree plots monitored for 3-years.

2) phenology_transects_LEWS: Walking transects between plots. Comparison of LEWS forest (PF) vs. community forest (CF) (aka protected forest vs. mixed-use mosaic bordering pulau) represented by observations of fruits along transects during our 2nd and 3rd year of surveys.

3) treeplots_LEWS: location information for each tree plot

The second tab of each excel dataset includes meta-data. If you have additional questions, please contact corresponding author for more details regarding this study, as some information has been omitted from original datasets e.g. information not needed for present analysis.