Does litter decomposition vary between the foraging pits of two soil‐disturbing mammal species?

Abstract

Soil‐disturbing animals play a critical role in many ecosystem processes. The loss of native soil‐foraging mammals (e.g. greater bilby Macrotis lagotis; burrowing bettong, Bettongia lesueur) throughout vast areas of Australia has altered fundamental soil processes such as decomposition. Little is known about whether surviving native soil‐disturbing animals (e.g. short‐beaked echidna, Tachyglossus aculeatus) produce soil disturbances that are functionally equivalent to those of locally‐extinct native animals. We used a litter bag study to compare abiotic and biotic mechanisms of decomposition within the foraging pits of two native mammal species. We compared decomposition rates between landforms, which we used as a surrogate for soil texture; grass species Austrostipa scabra subsp. scabra and Triodia scariosa subsp. scariosa, which we used as our substrates; and the effects of chemically excluding fungi and/or termites. There were initial differences in the organic mass loss between echidna and bilby/bettong foraging pits, with bilby/bettong pits losing more over 30 days, and echidnas losing more over 63 days. However, over 396 days there was no significant difference between the two pit types. Landform (soil texture) and chemical exclusion of termites and fungi did not affect our measures of decomposition until the final stage of the study. The two grass species lost significantly different amounts of organic material at each collection interval, with Austrostipa losing more at 30, 63 and 130 days and Triodia losing more at the final 396 day collection. This provided the most consistent effect on decomposition. Our results highlight the temporal idiosyncrasies in the various drivers of decomposition in this dune‐swale system. Overall, this study provides evidence that the foraging pits of the short‐beaked echidna do not differ markedly from those of the locally extinct greater bilby and burrowing bettong in terms of their capacity to maintain rates of decomposition at an annual scale. Copyright © 2015 John Wiley & Sons, Ltd.

Soil erodibility as impacted by vegetation restoration strategies on the Loess Plateau of China

“…The PR of the slope farmland was greater than that of the five restored lands. Notable differences were found among the five restored lands (Figure 7) due to the differences in BD and LD, driven by different vegetation types and their microenvironment (Wang et al, 2014a;Sun et al, 2016;Travers and Eldridge, 2016;Wang et al, 2018a).…”

Contrasting effects of two mammalian soil engineers on microbial communities

“…The shallower but wider echidna pits (Eldridge ) trapped substantially more litter (Fig. ; Travers & Eldridge ), and have been shown to retain more moisture than the soil surface, even after extended dry periods (Eldridge & Mensinga ). This would likely extend the period over which decomposition and mineralization occur.…”

Rainfall‐dependent impacts of threatened ecosystem engineers on organic matter cycling

“…Digging mammals are thus likely to have a greater effect in water‐limited ecosystems than in mesic systems. Although the role of digging mammals in organic matter decomposition has seldom been measured (but see Coggan et al, ; Travers & Eldridge, ), digging mammals contribute to important ecosystem services by altering soil conditions while foraging (Whitford & Kay, ). Pits and burrows created by mammals accumulate organic matter, seeds and water, creating resource‐rich pools for soil invertebrates (e.g.…”