Estimating Stand Volume and Above-Ground Biomass of Urban Forests Using LiDAR

Vincenzo Giannico,Lucia Pesola,Ranjeet John,Jiquan Chen,Raffaele Lafortezza,Giovanni Sanesi

doi:10.3390/rs8040339

Abstract

Assessing forest stand conditions in urban and peri-urban areas is essential to support ecosystem service planning and management, as most of the ecosystem services provided are a consequence of forest stand characteristics. However, collecting data for assessing forest stand conditions is time consuming and labor intensive. A plausible approach for addressing this issue is to establish a relationship between in situ measurements of stand characteristics and data from airborne laser scanning (LiDAR). In this study we assessed forest stand volume and above-ground biomass (AGB) in a broadleaved urban forest, using a combination of LiDAR-derived metrics, which takes the form of a forest allometric model. We tested various methods for extracting proxies of basal area (BA) and mean stand height (H) from the LiDAR point-cloud distribution and evaluated the performance of different models in estimating forest stand volume and AGB. The best predictors for both models were the scale parameters of the Weibull distribution of all returns (except the first) (proxy of BA) and the 95th percentile of the distribution of all first returns (proxy of H). The R2 were 0.81 (p < 0.01) for the stand volume model and 0.77 (p < 0.01) for the AGB model with a RMSE of 23.66 m3·ha−1 (23.3%) and 19.59 Mg·ha−1 (23.9%), respectively. We found that a combination of two LiDAR-derived variables (i.e., proxy of BA and proxy of H), which take the form of a forest allometric model, can be used to estimate stand volume and above-ground biomass in broadleaved urban forest areas. Our results can be compared to other studies conducted using LiDAR in broadleaved forests with similar methods.

Highlights

In recent decades, considerable amounts of afforestation and reforestation projects have been undertaken to address the increasing environmental issues related to climate change effects, urban sprawl, soil reclamation, soil sealing and degradation, biodiversity loss, water and air purification, etc., in most cities [1,2,3]
Light Detection and Ranging (LiDAR)-based applications can be used in connection with urban forest inventories, to derive information about the amount of carbon stored in the above-ground biomass
Assessing forest stand conditions in urban and peri-urban areas is essential to support ecosystem service planning and management, as most of the ecosystem services provided are a consequence of forest stand characteristics

Summary

Introduction

Considerable amounts of afforestation and reforestation projects have been undertaken to address the increasing environmental issues related to climate change effects, urban sprawl, soil reclamation, soil sealing and degradation, biodiversity loss, water and air purification, etc., in most cities [1,2,3]. These “new” forests, namely urban forest plantations, are normally established over abandoned lands (e.g., former industrial sites) to enhance ecosystem services (ESS) for local communities [4,5]. Remote Sens. 2016, 8, 339; doi:10.3390/rs8040339 www.mdpi.com/journal/remotesensing

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