DOI: 10.5061/dryad.0zpc8678x
title: Utilizing 360° photography to assess forest recovery seven years after hurricane impact

description: Many forestry studies rely on obtaining measurements on forest vertical
 structure, canopy closure, ground cover, and other data types through the
 use of manual labor, which is time-consuming, expensive, labor-intensive,
 and may not be feasible following a major hurricane. We established a
 total of 75 survey points across the trails of Las Casas de la Selva, a
 sustainable forestry plantation located in Patillas, Puerto Rico. The
 property took a direct hit from Hurricane Maria, a Category 4 storm with
 winds of up to 241 kph, on September 20, 2017. We took 360° photos at each
 survey point seven years later, which were then analyzed within a virtual
 reality environment to quantify forest vertical structure and transformed
 them into two batches of hemispherical photos, with one set focused on the
 canopy and the other on the ground. Collecting data in this way opens up
 the possibility for monitoring forest/vegetation health over time, as
 sites at trails are easy to access, and only 360° photos are needed. We
 computed the Vertical Habitat Diversity Index (VHDI) from the amount of
 foliage in 4 strata: herbaceous, shrub, understory, and canopy.
description: <strong>Assessment of Forest Vertical
 Structure:</strong> To assess the forest's
 vertical structure, we analyzed our 360° photos within an Oculus Go
 Virtual Reality Headset. For each photo, the presence of four layers was
 determined, which includes (1) Herbaceous Layer, (2) Shrub Layer, (3)
 Understory Layer, and (4) Canopy Layer. The different layers were
 primarily determined by the height of the vegetation. The herbaceous layer
 consisted of vegetation that had no woody stems, which included grass,
 ferns, and vines. For the herbaceous layer, the height ranged from 0.15 to
 1.3 meters. The shrub layer consisted of plants with woody stems, such as
 shrubs and small trees. This layer's height ranged from 1.3 to 4.3
 meters. The understory layer consists of vegetation in a wooded area where
 shrubs and trees are growing between the forest canopy and the forest
 floor. In this layer, the height ranged from 4.3 meters up to just below
 the canopy. Finally, the canopy layer consists of the top layer of a
 forest, which makes up the crowns of all the trees that overlap to form
 the roof over the rest of the forest. To determine the presence of these
 layers within the VR headset, Caslin first selected a landmark location
 (e.g., a tree or landscape feature). Next, turning clockwise, he recorded
 the presence of foliage in each of the 4 layers within 30° slices of the
 360° view to capture the entire image. Throughout the analysis for each
 photo, the PI recorded himself and then listened to the recording later to
 enter the data within a spreadsheet. Following Bai’s (2024) method, we
 calculated a Vertical Habitat Diversity Index (VHDI) by applying the
 Shannon-Weiner Index to these data, using layer for “species” and
 frequency of each layer as “abundance”. 
 <strong>Assessment of Ground Cover
 Vegetation</strong>:  To analyze the ground
 cover, we transformed each 360° photo into a hemispherical photo focusing
 on the ground, using GIMP version 2.10.12. We batch processed images
 within GIMP using an additional plugin called BIMP (Batch Image
 Manipulation Plugin). Next, we created a systematic point sampling grid
 utilizing Krita version 5.2.6. A total of 51 sample points were overlaid
 on each hemispherical photo. The ground cover type was then determined at
 each of the 51 systematic point locations in each photo.
 <strong>Assessment of Forest Canopy
 Closure</strong>:  To measure canopy closure, we
 again transformed the 75 360° photos into hemispherical images pointing up
 rather than down, i.e., only focusing on the canopy and excluding the
 ground. Each photo was then separately analyzed utilizing the % Cover app.
 The % Cover app is an environmental application that was designed to be
 used on iOS devices and provides a direct estimate of canopy
 closure.
description: # Utilizing 360° photography to assess forest recovery seven years after
 hurricane impact Dataset DOI:
 [10.5061/dryad.0zpc8678x](10.5061/dryad.0zpc8678x) ## Description of the
 data and file structure Data is from “Utilizing 360° photography to assess
 forest recovery seven years after hurricane impact” This dataset consists
 of 360° photos taken to assess the recovery of different components of a
 mixed sustainable Tabonuco/plantation forest. We established 75 survey
 points along the trails of *Las Casas de la Selva*, a sustainable forestry
 project located in Patillas, Puerto Rico. This site was directly impacted
 by Hurricane Maria—a Category 4 storm with wind speeds reaching up to 241
 km/h—on September 20, 2017. Seven years after the hurricane, we captured
 360° images at each survey point. These images were later analyzed in a
 virtual reality environment to assess vertical forest structure and were
 processed into two sets of hemispherical photographs: one focused on the
 forest canopy and the other on ground-level vegetation. This method of
 data collection offers a practical approach for long-term monitoring of
 forest and vegetation health. Because survey points are positioned along
 accessible trails and only require 360° images, repeated monitoring can be
 conducted with minimal disruption. From these images, we calculated the
 Vertical Habitat Diversity Index (VHDI) by estimating the proportion of
 foliage present across four vegetation strata: herbaceous, shrub,
 understory, and canopy. Number of Photos: 75 File Size: 304 MB Data was
 derived from the following sources: * Ricoh Theta V 4k 360 Spherical
 Camera ## 360° Photos Listed in Order Photo1_R0011537.JPG
 Photo2_R0011541.JPG Photo3_R0011545_Cropped.JPG
 Photo4_R0011359_Cropped.JPG Photo5_R0011354.JPG
 Photo6_R0011349_Cropped.JPG Photo7_R0011342.JPG
 Photo8_R0011337_Cropped.JPG Photo9_R0011271_Cropped.JPG
 Photo11_R0011276.JPG Photo12_R0011282.JPG Photo14_R0011289.JPG
 Photo15_R0011294.JPG Photo16_R0011299.JPG Photo18_R0011305.JPG
 Photo19_R0011311.JPG Photo20_R0011319.JPG Photo22_R0011322.JPG
 Photo23_R0011335.JPG Photo24_R0011365.JPG Photo25_R0011369.JPG
 Photo26_R0011375_Cropped.JPG Photo27_R0011380_Cropped.JPG
 Photo28_R0011386_Cropped.JPG Photo30_R0011447_Cropped.JPG
 Photo31_R0011416_Cropped.JPG Photo32_R0011410.JPG Photo33_R0011405.JPG
 Photo34_R0011400_Cropped.JPG Photo35_R0011395.JPG
 Photo36_R0011390_Cropped.JPG Photo37_R0011442.JPG
 Photo38_R0011437_Cropped.JPG Photo39_R0011432.JPG
 Photo40_R0011428_Cropped.JPG Photo41_R0011421.JPG
 Photo42_R0011549_Cropped.JPG Photo43_R0011554_Cropped.JPG
 Photo44_R0011559.JPG Photo45_R0011562_Cropped.JPG
 Photo46_R0011602_Cropped.JPG Photo47_R0011522.JPG
 Photo48_R0011477_Cropped.JPG Photo49_R0011472.JPG Photo50_R0011467.JPG
 Photo51_R0011462.JPG Photo52_R0011457.JPG Photo53_R0011452_Cropped.JPG
 Photo54_R0011597_Cropped.JPG Photo55_R0011593_Cropped.JPG
 Photo56_R0011584_Cropped.JPG Photo57_R0011589_Cropped.JPG
 Photo58_R0011501_Cropped.JPG Photo59_R0011497.JPG
 Photo60_R0011492_Cropped.JPG Photo61_R0011487_Cropped.JPG
 Photo62_R0011482.JPG Photo63_R0011580.JPG Photo64_R0011575_Cropped.JPG
 Photo66_R0011519_Cropped.JPG Photo67_R0011515_Cropped.JPG
 Photo68_R0011510_Cropped.JPG Photo69_R0011505.JPG
 Photo73_R0011571_Cropped.JPG Photo74_R0011566.JPG Photo78_R0011625.JPG
 Photo79_R0011621.JPG Photo80_R0011639.JPG Photo81_R0011642_Cropped.JPG
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 Photo88_R0011605_Cropped.JPG Photo89_R0011609_Cropped.JPG
 Photo103_R0011529.JPG Photo104_R0011532_Cropped.JPG