Historical Disturbance Trends: Initial Results

First round of results from the historical disturbance trends project
Author
Published

May 29, 2023

Parameter Values and Thresholds

Tuning: LT - GEE Defaults

Minimum Magnitude: 50

Minimum Patch size: 0.27 ha (3 pixels)

Land Acquisition

Cumulative area of state ownership for Adirondack Forest Preserve land from 1990 - 2022. NYS currently owns 1,000,598 ha of land within the park boundaries based on our maps.

Man Kendall Test Results for Patch Level Metrics

Metric Man Kendall Statistic Normalized Test Statistic p Value Trend Sens Slope
area 262 4.2325 0.0000 increasing 0.0144
cai 294 4.7514 0.0000 increasing 0.0533
circle 294 4.7514 0.0000 increasing 0.0533
contig 294 4.7514 0.0000 increasing 0.0533
core 300 4.8487 0.0000 increasing 0.0064
enn 200 3.2271 0.0013 increasing 0.9019
frac -132 -2.1244 0.0336 decreasing -0.0001
gyrate 198 3.1946 0.0014 increasing 0.1235
ncore 230 3.7136 0.0002 increasing 0.0044
para -240 -3.8757 0.0001 decreasing -0.0001
perim 196 3.1622 0.0016 increasing 3.5452
shape -34 -0.5351 0.5926 no trend -0.0004
mean_mag 118 1.8973 0.0578 no trend 0.7423
percent_area_dist -50 -0.7946 0.4268 no trend -0.0166

Metric Plots

All patch metrics derived from the landscape metrics package in r. Descriptions of the patch metrics can be found here.

Average disturbance patch size annually from 1990 - 2022.

Average core area index for disturbance patches from 1990 - 2022

Average size of smallest circumscribing circle for disturbance patches 1990 -2022

Average contiguity index for disturbance patches 1990 - 2022

Average size of patch core area from 1990 - 2022

Average distance to closest neighboring patch annually from 1990 - 2022

Average fractal dimension index from 1990 - 2022

Average radius of gyration for disturbance patches from 1990 - 2022

Average number of core areas in one disturbance patch from 1990 - 2022

Average perimeter to area ratio for disturbance patches 1990 - 2022

Average length of disturbance patch perimeter from 1990 - 2022

Average shape index for disturbance patches 1990 - 2022

Average disturbance magnitude of disturbance 1990 - 2022

Percentage of forest preserve land disturbed annually from 1990 - 2022