Tree Weights of Avicennia germinans in Mangrove Ecosystems Along the Guyana Coastline

TL;DR

This study compares tree biomass in natural, degraded, and restored mangrove ecosystems along Guyana's coast, finding that natural ecosystems have higher biomass despite restored areas having taller trees.

Contribution

The study introduces a novel comparison of biomass allocation in Avicennia germinans trees across different ecosystem types using plotless sampling and allometric equations.

Findings

Natural ecosystems had higher aboveground, trunk, and root weights compared to restored ecosystems.

Tree biomass allocation is strongly correlated with ecosystem type and disturbance levels.

Restored ecosystems had taller trees but lower biomass per hectare than natural ones.

Abstract

Mangroves are known as highly functional and productive ecosystems despite the numerous human and environmental disturbances they face continuously. These disturbances are known to affect their ecosystem states as well as their biomass allocation in their roots, trunks, stems, and leaves. We utilized a combination of plotless sampling methods and established common allometric equations to examine and compare the aboveground, trunk, and root weights of over 600
Avicennia germinans
trees found along the Guyana coastline in natural, degraded, and restored ecosystems. Our results highlighted that while the restored ecosystems possessed taller trees with greater densities, the natural ecosystems possessed trees with greater aboveground (54396.24 kg/ha), trunk (19127.08 kg/ha), and root weights (20984.44 kg/ha) due to greater diameter at breast height values (> 30–40 cm). Furthermore, positive correlation coefficients (0.97 < r
s < 1.00) and regression values (p < 0.05) yielded compelling evidence in favor of the relationship between biomass allocation through tree organ weights and ecosystem types. Our findings support the notion that the composition and magnitude of disturbances within an ecosystem may affect mangrove tree biomass, hence influencing the net primary productivity of mangrove forests over time. This may have implications for their ability to accumulate and allocate biomass, as well as store carbon in the future. As such, the proactive conservation of existing mangrove forests is crucial for sustaining their productivity and viability, as well as augmenting their significance in biogeochemical cycles and their role in mitigating climate change.

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