New study reveals larger insects' critical role in decomposition in arid ecosystems

The Hebrew University of Jerusalem

 

image: 

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

view more 

Credit: Viraj R Torsekar

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.

Link to pictures: https://drive.google.com/drive/folders/19a7FbAw4DvYeg5_GdvFJzc6p-0gMuBqp?usp=sharing

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.

A millipede foraging for plant litter in a semiarid landscape. 

  

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

Credit

Nevo Sagi

---

Journal

eLife

DOI

10.7554/eLife.93656.3 

Method of Research

Experimental study

Subject of Research

Animals

Article Title

Contrasting responses to aridity by different-sized decomposers cause similar decomposition rates across a precipitation gradient