Litchfield Savanna Wood Block Decomposition Data 2019 

Wood block decomposition assessment at the Litchfield Savanna site is part of a global program looking at the influence of microbes and invertebrates on wood decay. A common protocol was developed exposing small (~400 cm3) pieces of a wood-substrate (untreated Pinus radiata) to the environment excluding and not-excluding macroinvertebrates (e.g. termites) by the use of a plastic mesh. 

We at TERN acknowledge the Traditional Owners and Custodians throughout Australia, New Zealand and all nations. We honour their profound connections to land, water, biodiversity and culture and pay our respects to their Elders past, present and emerging. Since 2016 this project has been part of the Australian SuperSites Network (SuperSites). SuperSites is a Facility within the Terrestrial Ecosystem Research Network (TERN). TERN is supported by the Australian Government through the National Collaborative Research Infrastructure Strategy. NSFDEB-NERC Collaborative Research #1655759: Tropical deadwood carbon fluxes: Improving carbon models by incorporating termites and microbes. Investigator(s): Amy Zanne (Principal Investigator), Paul Eggleton (Co-Principal Investigator). Decomposer interactions and carbon flux: termite influences on microbial wood decay within the Australian SuperSite Network, J. Powell. Western Sydney University. The Thomas Davies Research Grant for Marine, Soil and Plant Biology, 2016. 

This will provide baseline information on the relative rates of decomposition that can be ascribed to saprotrophic microbes and invertebrates in different ecosystems across Australia and the world. The use of a common wood substrate allows for direct comparison among studies. Note: This data is part of the NSFDEB-NERC Collaborative Research #1655759: Tropical deadwood carbon fluxes: Improving carbon models by incorporating termites and microbes. Investigator(s): Amy Zanne (Principal Investigator), Paul Eggleton (Co-Principal Investigator). Decomposer interactions and carbon flux: termite influences on microbial wood decay within the Australian SuperSite Network, J. Powell. Western Sydney University. The Thomas Davies Research Grant for Marine, Soil and Plant Biology, 2016. 

Wood block bait preparation is described in detail in Cheesman et al., 2017. Relative roles of termites and saprotrophic microbes as drivers of wood decay: A wood block test. Austral Ecology. (supplementary appendix 2) https://doi.org/10.1111/aec.12561 Control Baits: Control Baits were made of planed planks of chemically untreated Pinus radiata with a total volume of ~400 cm3 (dried at 120˚ C for 48 h and allowed to cool to room temp under air conditioned lab environment before weighing) wrapped in nylon mesh material to exclude macrofauna. Control baits were labelled with aluminium tags T01 - T60 Termite Baits: Termite Baits are the same as Control baits but have 10 holes (5 mm diameter) punched into the nylon mesh with a hole punch to allow termite access on the underside of the bait – termite foraging is from below. An aluminium tag is included in each bag with the Bait ID. Termite baits were labelled with aluminium tags T01 - T60. Twenty bait stations were established in a linear transect (E-W selected for convenience) over 95 m with 5 m spacing, in close proximity, but external to the Litchfield Savanna core 1 ha vegetation plot. Stations were relocated off the line transect if the designated point was <0.5m from coarse woody debris, an existing termite mound, exposed rocks or substantial water flow paths, as these features were considered likely to alter termite behaviour. The area immediately under the baits had intact leaf litter removed and duff layer homogenised by scraping. Where there was a fire risk, the grass fuel load in an area surrounding (approx. 1 m) may be reduced by cutting. Baits were staked into the ground using individual pegs at the uphill edge of any surficial gradient (i.e., the top edge of where water would flow across the block in that landscape) with the side of the bait with holes (on Termite baits) in contact with the soil. As a minimum, 4 baits (2 Control, 2 Termite exposed baits) were set out at each station and covered by a 0.5 x 0.5 m square of 70% green shade cloth, which is itself pegged to the ground to reduce UV degradation and disturbance by fauna. Ten (alternate) bait stations had baits 4 baits (2 Control, 2 Termite exposed) deployed for microbial assessments. After 12 months, 2 baits (1 Control, 1 Termite exposed) were recovered from each of 20 bait stations for mass loss assessment. Two baits (1 Control, 1 Termite exposed) were recovered from each of 10 (alternate) bait stations for microbial assessments. After 12 months, baits (1 Control, 1 Termite exposed) were recovered from each of 20 bait stations for mass loss assessment. Whole (unopened) baits were placed in sealed plastic bags and kept in the dark until assessment. For mass loss assessments, wood block baits were unpacked and assessed for fungal and termite damage (following Davies et al., 1999. Successional response of a tropical forest termite assemblage to experimental habitat perturbation. J. Appl. Ecol. 36, 946-62.), presence of imported carton or soil, presence/absence of termites, other insects, fungal fruiting bodies, plant roots. Bait were photographed before drying at 105°C for 72 h then weighed. Fungal and termite damage ratings Fungal and termite damage, was rated 0-4 following Davies et al. 1999. When termite damage is high, it becomes impossible to determine fungal damage and thus a value of NA (Not Applicable) was recorded. 0 = sound wood 1 = perceptible but very limited damage 2 = clear changes to a moderate extent 3 = severe changes 4 = breakage of the wood block Fungal Damage 0 = No perceptible fungal attack or softening 1 = Discolouration and very superficial degradation or softening up to 1 mm in depth 2 = Softening to a depth of 2 - 3 mm deep over all or part of the block 3 = Marked decay in wood to a depth of 3-5 mm over a wide surface area or by softening to a greater depth (10-15 mm) over a smaller area. 4 = Breakage due to fungal attack and softening. Termite Damage 0 = No perceptible termite attack 1 = Very superficial deterioration to 1-2 mm in depth at some points or over several cm2 2 = Damage from 2 to 5 mm in depth over several cm 2, or with scattered points down to a depth exceeding 5 mm, or by different combinations of the two types. 3 = Extended and deep destruction from 5 to 10 mm in depth, or tunnels reaching the centre of the block, or by different combinations of the two 4 = Breakage due to extent of termite tunneling Any termites or insect collected from within nylon bags or wood blocks were transferred to 70% ethanol for storage. Any fungal fruiting bodies were air dried and weighed. Any ingrown plant roots were collected and scanned, then dried at 65˚C for 24 h and weighed.