New study reveals that in arid ecosystems, larger arthropods such as termites and beetles play a crucial role in decomposition, challenging the traditional view that microbial activity dominates this process in dry environments. By demonstrating that macro-decomposition can peak during the summer in arid sites and that overall decomposition rates in these regions can be similar to or even exceed those in wetter climates, the research provides new insights into how decomposition functions in drylands and its implications for global carbon cycling and ecosystem management.

 

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Researchers from The Hebrew University of Jerusalem have discovered a potential solution to the long-standing "desert decomposition conundrum" in a new study in eLife. Led by Dr. Viraj Torsekar, Dr. Nevo Sagi and Professor Dror Hawlena from Hebrew University, the study challenges conventional beliefs about decomposition processes across different climate gradients. Traditionally, it was thought that decomposition rates were primarily driven by microorganisms and would decrease in drier environments. However, this new research uncovers that larger arthropods play a crucial and previously underappreciated role in arid ecosystems.

Key Findings:

• Decomposers of different sizes respond distinctively to precipitation levels.
• Microbial decomposition increases with precipitation during winter months.
• Macro-decomposition, driven by larger arthropods such as termites and beetles, peaks in arid sites during the summer.
• These contrasting responses result in similar overall decomposition rates across most of the precipitation gradient.

The researchers conducted their study across seven sites in Israel, ranging from hyper-arid to Mediterranean climates. They utilized innovative litter baskets with varying mesh sizes to isolate the effects of different-sized decomposers.

"Our findings show that the contrasting climate dependencies of micro- and macro-fauna decomposers lead to unexpectedly high decomposition rates in arid environments," says Dr. Torsekar. "This provides a plausible explanation for why plant litter decomposition in drylands occurs faster than previously thought—a puzzle that has challenged scientists for decades."

"This research highlights the overlooked role of larger arthropods in dry ecosystems," adds Dr. Sagi. "By revealing that arid regions can support decomposition rates similar to or higher than wetter areas, we hope to inspire new strategies for conserving these vulnerable ecosystems."

Professor Hawlena concludes, "Understanding the dynamics of decomposition in drylands is essential for conserving and restoring critical ecosystem processes, particularly as these regions expand globally. Our findings also have significant implications for global carbon cycling and climate change models."

The study's implications reach beyond ecology, potentially influencing climate change models and conservation strategies for arid ecosystems worldwide.

The research paper titled “Contrasting responses to aridity by different-sized decomposers cause similar decomposition rates across a precipitation gradient” is now available at eLife and can be accessed at https://elifesciences.org/articles/93656

 DOI 10.7554/eLife.93656.3

 

Pictures

A Macrodecomposer Foraging in Dryland

An isopod, well-adapted to the harsh conditions of arid-lands, crawls on the desert floor in search of plant litter. Credit – Viraj R Torsekar

 

Beetles

Beetles account for most biomass of macrodecomposers across most landscapes and play a crucial role in plant litter decomposition. Credit - Nevo Sagi

 

A millipede foraging for plant litter in a semiarid landscape. Credit - Nevo Sagi

 

Researchers:

Viraj Torsekar^1,2, Nevo Sagi¹, J Alfred Daniel³, Yael Hawlena¹, Efrat Gavish-Regev³, Dror Hawlena^1,3

Institution:

1. Risk-Management Ecology Lab, Department of Ecology, Evolution & Behavior, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem
2. Theoretical Ecology and Evolution Lab, Centre for Ecological Sciences, Indian Institute of Science
3. The National Natural History Collections, The Hebrew University of Jerusalem

 

The Hebrew University of Jerusalem is Israel’s premier academic and research institution. With over 23,000 students from 90 countries, it is a hub for advancing scientific knowledge and holds a significant role in Israel’s civilian scientific research output, accounting for nearly 40% of it and has registered over 11,000 patents. The university’s faculty and alumni have earned eight Nobel Prizes, two Turing Awards a Fields Medal, underscoring their contributions to ground-breaking discoveries. In the global arena, the Hebrew University ranks 81st according to the Shanghai Ranking. To learn more about the university’s academic programs, research initiatives, and achievements, visit the official website at http://new.huji.ac.il/en