Necromass Carbon Stock in a Secondary Atlantic Forest Fragment in Brazil

Paulo Henrique Villanova,Samuel José Silva Soares Da Rocha,Carlos Pedro Boechat Soares,José Cola Zanuncio,Liniker Fernandes Da Silva,Carlos Moreira Miquelino Eleto Torres,Laércio Antônio Gonçalves Jacovine,Bruno Leão Said Schettini

doi:10.3390/f10100833

Paulo Henrique Villanova, Samuel José Silva Soares Da Rocha + Show 6 more

Open Access

https://doi.org/10.3390/f10100833

Copy DOI

Abstract

Necromass has a relevant role to play in the carbon stock of forest ecosystems, especially with the increase of tree mortality due to climate change. Despite this importance, its quantification is often neglected in tropical forests. The objective of this study was to quantify the carbon storage in a secondary Atlantic Forest fragment in Viçosa, Minas Gerais, Brazil. Coarse Woody Debris (CWD), standing dead trees (snags), and litter were quantified in twenty 10 m x 50 m plots randomly positioned throughout the forest area (simple random sampling). Data were collected during 2015, from July to December. The CWD and snags volumes were determined by the Smalian method and by allometric equations, respectively. The necromass of these components was estimated by multiplying the volume by the apparent density at each decomposition classes. The litter necromass was estimated by the proportionality method and the average of the extrapolated estimates per hectare. The carbon stock of the three components was quantified by multiplying the necromass and the carbon wood content. The total volume of dead wood, including CWD and snag, was 23.6 ± 0.9 m3 ha−1, being produced mainly by the competition for resources, senescence, and anthropic and climatic disturbances. The total necromass was 16.3 ± 0.4 Mg ha−1. The total carbon stock in necromass was 7.3 ± 0.2 MgC ha−1. The CWD, snag and litter stocked 3.0 ± 0.1, 1.8 ± 0.1, and 2.5 ± 0.1 MgC ha−1, respectively. These results demonstrate that although necromass has a lower carbon stock compared to biomass, neglecting its quantification may lead to underestimation of the carbon balance of forest ecosystems and their potential to mitigate climate change.

Highlights

The Atlantic Forest is the most degraded biome in Brazil with most of its remaining forest fragments being smaller than 50 ha [1,2,3]
The apparent density and carbon content for the quantification of necromass and carbon stock, respectively, varied according to the type of component and the decomposition class of the dead wood (Table 2)
Necromass found in the secondary Atlantic Forest can store large amounts of carbon and should be included in studies that aim to quantify the forest ecosystem carbon balance

Summary

Introduction

The Atlantic Forest is the most degraded biome in Brazil with most of its remaining forest fragments being smaller than 50 ha [1,2,3]. The main driver responsible for this fragmentation was the pressure exerted by human activities, such as agriculture, logging, and urban growth [4,5,6]. These activities together with climate change have affected forest dynamics, altering carbon storage and the tree mortality rate [7,8,9]. This increase in tree mortality leads to a greater accumulation of necromass (dead organic matter) that can remain on tropical forest soil for more than 30 years [10]. Forests for invertebrates and vertebrates [13], integration of forest nutrient cycling [14,15], and storing carbon phase of the forest ecosystem, providing food for saproxylic organisms [11,12], habitat for invertebrates [16,17,18].

Objectives

Methods

Results

Discussion

Conclusion