Biodiversity loss reduces global terrestrial carbon storage – Nature Communications

Abstract

Natural ecosystems store significant amounts of carbon globally, which is absorbed from the atmosphere by organisms to build structures such as tree bark or root systems. The potential for carbon sequestration in an ecosystem is closely linked to its biological diversity. However, many carbon sequestration models overlook the role of biodiversity in carbon storage when making future projections. This report assesses the impact of plant biodiversity loss on carbon storage under various climate and land-use change scenarios. By integrating a macroecological model that projects changes in vascular plant richness with empirical data on biodiversity and biomass relationships, we find that declines in biodiversity due to climate and land use changes could lead to a global loss of between 7.44-103.14 PgC (global sustainability scenario) and 10.87-145.95 PgC (fossil-fueled development scenario). This suggests a feedback loop where higher levels of climate change result in greater biodiversity loss, leading to increased carbon emissions and further climate change. Conversely, conserving and restoring biodiversity can aid in achieving climate change mitigation goals.

Introduction

Climate change and biodiversity loss are interconnected crises that are most effectively addressed together. Studies consistently show that more diverse plant assemblages result in higher biomass production and carbon sequestration. Various mechanisms explain this phenomenon, such as different species utilizing resources more efficiently, reducing competition, and increasing facilitation. Biodiversity loss can significantly impact productivity within ecosystems, comparable to elevated carbon dioxide levels or drought effects. While climate change affects biodiversity, biodiversity loss also influences climate change by altering carbon sequestration and storage. Despite the contribution of biodiversity to carbon sequestration, initiatives often focus on increasing the extent of natural ecosystems rather than their diversity or composition.

Ecosystem service models do not always consider the effects of biodiversity. Models projecting changes in biodiversity, ecosystem functioning, and services typically operate independently without accounting for interactions or feedbacks. For example, Earth System Models (ESMs) often use a limited number of plant functional types and exclude biodiversity-productivity mechanisms, leading to potentially inaccurate projections of ecosystem function and services. Incorporating biodiversity-ecosystem function relationships could improve model accuracy over long timescales as biodiversity effects become stronger.

Results

Under the global sustainability scenario, ecoregions lost an average of 16.0% of plant species, leading to an average biomass loss of 4.4%. Under the fossil-fueled development scenario, ecoregions lost an average of 20.8% of plant species, resulting in an average biomass loss of 5.9%. Biodiversity and biomass losses were particularly high in the tropics, southern Australia, eastern Europe, and parts of South America.

Overall vegetation carbon loss was greatest in tropical regions of South America, central Africa, and Southeast Asia. Biodiversity loss projections and vegetation carbon were both high in the Amazon, making it a hotspot for biodiversity-driven carbon loss. Biodiversity declines led to a long-term loss of 7.40-102.68 PgC of vegetation carbon under global sustainability and 10.83-145.32 PgC under fossil-fueled development.

Discussion

This study predicts that biodiversity loss can reduce global carbon storage potential significantly. Greater loss is projected under intense climate change and land-use change scenarios, but even sustainability scenarios carry high risks. This creates a positive feedback loop where higher levels of climate change lead to greater biodiversity loss, resulting in increased carbon emissions.

Priority areas for biodiversity conservation and climate change mitigation could change by accounting for the role of biodiversity in promoting carbon storage. Our analysis points to the important role that maintaining and enhancing plant species diversity within natural vegetation areas can play in addressing climate change.

Methods

1. Use the BILBI model to estimate the proportion of plant species expected to persist in each ecoregion under different climate and land-use scenarios.
2. Use empirical relationships to link changes in species richness to changes in biomass.
3. Estimate total changes in carbon storage and compare to other global change drivers.

Data Availability

Data used in this study are available from various sources detailed within the article.

Code Availability

R scripts used for analysis are included as supplementary files.

Author Information

• Sarah R. Weiskopf – U.S. Geological Survey National Climate Adaptation Science Center, Reston, VA, USA; Department of Environmental Conservation, University of Massachusetts, Amherst, MA, USA
• Forest Isbell – Department of Ecology, Evolution and Behavior, University of Minnesota, Saint Paul, MN, USA

Ethics Declarations

The authors declare no competing interests.

Peer Review Information

This article was peer-reviewed by Rob Alkemade, Eduardo Gomes, and Aafke Schipper.

Rights and Permissions

This article is licensed under a Creative Commons Attribution 4.0 International License.

About this Article

Cite this article as: Weiskopf, S.R., Isbell, F., Arce-Plata, M.I., et al. Biodiversity loss reduces global terrestrial carbon storage. Nat Commun 15, 4354 (2024).

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