Carbon stock estimation of mixed-age date palm (Phoenix dactylifera L.) farms in northeastern Ethiopia

Mulugeta Betemariyam,Tamiru Kefalew

doi:10.1016/j.heliyon.2022.e08844

Abstract

The date palm (Phoenix dactylifera) is a fruit tree that grows from 392 to 1500 m above sea level. In addition to their socioeconomic, traditional, and religious value, it is a tree that tolerates high temperatures, drought, and salinity better than many other fruit crop plant species and plays an important role in the balancing and sequestration of atmospheric carbon. Date palm has been cultivated by agro pastoralists in Northeastern Ethiopia since ancient times, but no research has been done on the carbon stock of date palm farms (DPF) in the region. Therefore, the focus of the current study was to examine the carbon storage capacity in the biomass and soil of a DPF in the Aysaita and Afambo Districts of Northeastern Ethiopia. The ages of recorded date palm on the plot were classified into three age classes using information collected from the farm owners: 1st age class (for plantations less than 10 years), 2nd age class (for plantations between 10 and 20 years), and 3rd age class (for plantations older than 20 years). In the DPF, 45 main plots (20 m × 20 m) were established for tree species inventory. In the main plots, three 1 m × 1 m subplots were set up to collect soil samples. A total of 360 soil samples were collected; 180 for soil organic carbon fraction analysis and 180 for bulk density determination. The total carbon stock was calculated by adding the carbon stocks in biomass and soil (0–60 cm depth). Date palm trees accounted for 98.79% of total biomass carbon stocks in the date palm farm. The average aboveground biomass carbon stock of date palm trees older than 20 years was 1.55 and 1.36 times higher than the first and second age classes, respectively. Date palm trees between the ages of 5 and 20 years contributed 69.45% of total biomass carbon stocks (Mg C ha−1). Soil organic carbon made for 32.9% of total carbon stocks. Our research found that the date palm farm of this study would contribute to emission reduction and carbon sink enhancement, as well as improving local livelihoods in the study area.

Highlights

The date palm (Phoenix dactylifera) is a fruit tree that can be found in a wide range of geographic, soil, and climatic conditions around the world
In most agro pastoralist farms, there are less than 30 date palm trees
Prosopis juliflora is a woody plant that grows alongside date palm trees

Summary

Introduction

The date palm (Phoenix dactylifera) is a fruit tree that can be found in a wide range of geographic, soil, and climatic conditions around the world. It grows from 392 m below to 1500 m above sea level [1]. It tolerates high temperatures, drought and salinity more than many other fruit crop plant species [2]. Drought and salinity more than many other fruit crop plant species [2] It is a large tree with very dense leaves (nearly 4–5 m), and each leaf has approximately 150 leaflets (each leaflet is around 30 cm in length and 2 cm in width) [3]. The amount of CO2 absorbed is, proportional to the size of the plant's green component; the absorption of CO2 and carbon stocks in the trunk and roots of Date palms are higher than those of other tree species [4]

Methods

Discussion

Conclusion