Please use this identifier to cite or link to this item: http://hdl.handle.net/11667/158
Appears in Collections:University of Stirling Research Data
Title: Mt Hehuan treeline ecotone change
Creator(s): Morley, Peter J
Contact Email: morley.pete@gmail.com
Keywords: Climate change
Densification
Forest change
Treeline
Date Available: 27-Jul-2020
Citation: Morley, PJ (2020): Mt Hehuan treeline ecotone change. University of Stirling. Faculty of Natural Sciences. Dataset. http://hdl.handle.net/11667/158
Publisher: University of Stirling. Faculty of Natural Sciences
Dataset Description (Abstract): This dataset details landcover change interpreted from historic aerial photography from the treeline ecotone of Mt. Hehuan, Taiwan, enabling change in the position and area of montane forest to be calculated at the elevational limit of the montane forest of Taiwan. The associated R files can be run to calculate change statistics presented in the paper 'Montane forest expansion at high elevations drives rapid reduction in non-forest area despite no change in mean forest elevation.' published in Journal of Biogeography - DOI: 10.1111/JBI.13951.
Dataset Description (TOC): The dataset is interpreted from four sets of aerial photography (P1-4) collected in 1963(P1), 1980(P2), 2001(P3) and 2016(P4) across a study are measuring 4072 ha from the Mt hehuan area of the Taiwanese Central Mountain Range. A proportional stratified random sampling design was used to assess change in forest distribution at the treeline ecotone. Sample plots were created that measure 15 x 15 m and slope orientation was used as a basis for stratification using 12 categories of slope aspect and incline attributes calculated from a high-resolution TanDEM-X Digital Elevation Model. Strata were based on four cardinal compass directions (± 45° in either direction) and three inclination classes (0-20°, 21-45° and > 46°). The number of samples taken in each stratum was proportional to the area of the study region occupied by the aspect-incline combination and a total of 2,785 sample plots were interpreted, equivalent to 1.54 % of the study area. Each sample is assigned one of four vegetation classes for each year in the change survey. Areas that meet the FAO Global Forest Resources Assessment (2018) criterion of a forest as an area with at least 10 % canopy cover and trees greater than 5 m in height are classified here as forest. Areas with small trees present within the plot that do not meet the thresholds of a forest as set out by the FAO definition were categorised as establishing forest. The scale of the aerial photography (≤0.5 m pixel size) is sufficient to discriminate differences in tree size based on crown size. Areas with partial removal of the forest canopy between time periods are categorised as disturbed and treeless areas are categorised here as non-forest areas. The R files provided carry out the change assessment for the results presented in the paper publised in Journal of Biogeography (DOI: 10.1111/JBI.13951 ). R files should be run from the master script to as this will set up the change analysis to account for the stratification of sample plots and will then subsequently calculate change statistics for the study area as a whole and by each aspect or incline class.
Type: dataset
Funder(s): NERC - Natural Environment Research Council
Contract/Grant Number: NE/L002590/1
Geographic Location(s): Taiwan, Mt. Hehuan
Time Period: 1963-2016
URI: http://hdl.handle.net/11667/158
Rights: Rights covered by the standard CC-BY 4.0 licence: https://creativecommons.org/licenses/by/4.0/
Affiliation(s) of Dataset Creator(s): University of Stirling (Biological and Environmental Sciences)

Files in This Item:
File Description SizeFormat 
HehuanChangeSample_P1P2P3P4.csv167.87 kBUnknownView/Open
ChangeAnalysisSetup.R11.6 kBUnknownView/Open
ChangeBySlope.R11.95 kBUnknownView/Open
ChangeByAspect.R12.28 kBUnknownView/Open
HehuanChangeAssessment_master.r2.13 kBUnknownView/Open
StudyAreaChangeP1P2P3P4.R15 kBUnknownView/Open


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