Condo or cuisine? The function of fine woody debris in driving decomposition, detritivores, and their predators
Data files
Sep 17, 2024 version files 374.21 KB
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All_Data_for_SELL_Publication_9-10-24.xlsx
346.70 KB
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README.md
27.51 KB
Abstract
Community structure and ecosystem function may be driven by the size or the energy within a given habitat, but these metrics (space and energy) are difficult to separate, especially in systems where the habitat itself is also food such as detritus. Only a handful of studies have attempted isolate potential mechanisms experimentally, which has left a notable knowledge gap in understanding the drivers of community structure and function. Here we tested whether fine woody debris (FWD) affects leaf litter communities primarily as a source of space or energy. We used a crossed factor design to isolate the effects of fine woody debris as space and energy, with four treatments: (1) no fine woody debris, (2) only energy-providing fine woody debris (sawdust), (3) only space-providing synthetic wood debris, and (4) a combination of both space and energy. We hypothesized that the highest levels of diversity, carnivore-to-detritivore ratio, and decomposition rate would occur on plots supplied with sawdust (representing energy), synthetic woody debris (representing space), or a combination of both, depending on the relative significance of fine woody debris as a source of either energy and space. After 7 months, FWD as a source of energy but not space led to decreased decomposer abundance and richness. Conversely, increased proportion of carnivores and labile substrate decomposition was primarily driven by FWD as a source of space. However, the fastest decomposition of more recalcitrant substrates required both space and energy (additive), and the synergy of space and energy supported the greatest proportion of carnivores. These results suggest that the presence of FWD in forest ecosystems supports increased diversity and decomposition through a synergistic interaction of space and energy and the maintenance of deadwood like FWD in forest ecosystems can thus significantly contribute to forest ecosystem function.
README: Condo or cuisine? The function of fine woody debris in driving decomposition, detritivores, and their predators
https://doi.org/10.5061/dryad.c866t1ggh
Description of the data and file structure
Here, we tested the relative importance of FWD as either a source of space or energy on BFW invertebrate community structure, relative abundance of low and high trophic levels (e.g., detritivores:carnivores), and decomposition of leaf litter. We separated the effects of FWD as a source of space and energy using a crossed factor design where FWD was either added to plots as (1) no FWD present (-Space, -Energy), (2) solely energy using FWD as sawdust (-Space, +Energy), (3) solely space using synthetic wood debris (+Space, -Energy), or (4) their combination (+Space,+Energy). Additionally, BFW community structure and function on experimental treatments were compared to natural plots that received no manipulation other than removal of new FWD inputs. We took site measurements of litterfall, standing fine woody debris stock, leaf litter standing stocks. We additionally measured decomposition over 7 months using artificial substrates (monthly) and natural substrates (once after 7 months). Leaf litter invertebrate communities were collected, identified, and their abundances recorded.
Files and variables
File: All_Data_for_SELL_Publication.xlsx
Description: All variables are described on the 'MetaData' sheet of the file and below.
Variables
Treatment Codes: | Treatment Code Description |
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FWD Addition (+S,-E) | Represents treatment where natural space and energy (FWD) were removed and only artificial space (synthetic materials) were added |
Full Removal (-S,-E) | Represents treatment where natural space and energy (FWD) were removed and no artificial space or energy were added |
Control (+S,+E) | Represents treatment where natural levels of natural space and energy (FWD) were unmanipulated at the start of the experiment |
FWD Removal SD Addition (-S,+E) | Represents treatment where natural space and energy (FWD) were removed and energy was added through sawdust created from FWD in the experiment site |
FWD Addition SD Addition (+S,+E) | Represents treatment where natural space and energy (FWD) were removed and artificial space (synthetic materials) and energy were added through sawdust created from FWD in the experiment site |
Notes | N/A Description |
N/A | When present in the data file means these data were not collected |
- | Sheet | Column | Description | | :--------------------------- | :-------------------------------------- | :--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | Inverts | Medium Extracted From | Leaflitter represents the litter collected from experimental plots; Synthetic FWD represents extractions from just the experimental fine woody debris (plastic) added to plots | | Inverts | Plot | The plot ID number samples were taken from | | Inverts | Treatment | The treatment applied to each plot; See Treatment Codes on Meta Data Sheet for information about treatments | | Inverts | Order | The highest taxonomic level of identification | | Inverts | Family | The lowest taxonomic level of identification | | Inverts | Number | The abundance of each taxon extracted from media | | Detritus | Plot | The plot ID number samples were taken from | | Detritus | Treatment | The treatment applied to each plot; See Treatment Codes on Meta Data Sheet for information about treatments | | Detritus | Corner 1 | Litter depth measurement in cm taken from one of the corners of 0.5m x 0.5m experimental plots at the end of the experiment | | Detritus | Corner 2 | Litter depth measurement in cm taken from one of the corners of 0.5m x 0.5m experimental plots at the end of the experiment | | Detritus | Corner 3 | Litter depth measurement in cm taken from one of the corners of 0.5m x 0.5m experimental plots at the end of the experiment | | Detritus | Corner 4 | Litter depth measurement in cm taken from one of the corners of 0.5m x 0.5m experimental plots at the end of the experiment | | Detritus | FWD Mass g | Total fine woody debris mass on each plot at the end of the experiment | | Detritus | Soil Initial Wet Mass (g) | Soil wet mass measured upon collection from field; a few samples were lost and are represented with N/A | | Detritus | Soil Final Dry Mass (g) | Soil dry mass measured after dried; a few samples were lost and are represented with N/A | | Detritus | ll Mass g | Total leaf litter mass on each plot at the end of the experiment | | Decomposition | Decomposition Substrate | The substrate used in litterbags to measure decomposition on each plot | | Decomposition | Collection Date | The date the litterbag with decomposition substrates were collected | | Decomposition | Plot # | The plot ID number samples were taken from | | Decomposition | Treatment | The treatment applied to each plot; See Treatment Codes on Meta Data Sheet for information about treatments | | Decomposition | Initial Mass (g) | Mass of the decomposition substrate prior to deployment in field | | Decomposition | Final Mass (g) | Mass of the decomposition substrate after collection from the field | | Chemistry | Substrate | Substrate on which chemistry analysis was conducted | | Chemistry | Plot | The plot ID number samples were taken from | | Chemistry | Treatment | The treatment applied to each plot; See Treatment Codes on Meta Data Sheet for information about treatments | | Chemistry | Carbon % | Carbon % | | Chemistry | Nitrogen % | Nitrogen % | | Chemistry | Aluminum, ppm | Aluminum, ppm | | Chemistry | Boron, ppm | Boron, ppm | | Chemistry | Calcium % | Calcium % | | Chemistry | Copper, ppm | Copper, ppm | | Chemistry | Iron, ppm | Iron, ppm | | Chemistry | Magnesium % | Magnesium % | | Chemistry | Manganese, ppm | Manganese, ppm | | Chemistry | Molybdenum, ppm | Molybdenum, ppm | | Chemistry | Phosphorus % | Phosphorus % | | Chemistry | Potassium % | Potassium % | | Chemistry | Sodium, ppm | Sodium, ppm | | Chemistry | Sulfur % | Sulfur % | | Chemistry | Zinc, ppm | Zinc, ppm | | Leaf Litterfall Data | Date | Date the leaf litter fallen in baskets were collected | | Leaf Litterfall Data | Basket Number | The specific identification number of each basket | | Leaf Litterfall Data | Tree Spiecies | Post oak or loblolly pine leaf litter measured; no other litter was measured | | Leaf Litterfall Data | Mass (g) | total mass of the litter collected in baskets for the specific species | | Initial Oak & Pine Estimates | Plot | The plot ID number samples were taken from; these refer to the initial quantification of fine woody debris and not experimental plots; Note: 2 samples were lost and are entered as N/A | | Initial Oak & Pine Estimates | Total Loblolly Pine Straw Mass (g) | The total mass of loblolly pine needles collected from non-expeimental plots used to estimate fine woody debris and leaf litter mass | | Initial Oak & Pine Estimates | Total Post Oak Mass (g) | The total mass of post oak leaves collected from non-expeimental plots used to estimate fine woody debris and leaf litter mass | | Initial Oak & Pine Estimates | Total Other Leaf Litter Debris Mass (g) | The total mass of just leaf litter (not fine wood debris) collected from non-expeimental plots used to estimate fine woody debris and leaf litter mass | | Initial FWD Collection Mass | Plot | The plot ID number samples were taken from; these refer to the initial quantification of fine woody debris and not experimental plots | | Initial FWD Collection Mass | Softwood (g) | The mass of all Non-bark softwood fine woody debris collected from plots at the start of the experiment | | Initial FWD Collection Mass | Hardwood (g) | The mass of all Non-bark hardwood fine woody debris collected from plots at the start of the experiment | | Initial FWD Collection Mass | Softwood Bark (g) | The mass of all softwood bark fine woody debris collected from plots at the start of the experiment | | Initial FWD Collection Mass | Hardwood Bark (g) | The mass of all hardwood bark fine woody debris collected from plots at the start of the experiment | | Initial FWD Collection Mass | Softwood Total (g) | The total mass (bark and non-bark) of all softwood fine woody debris collected on plots at the start of the experiment | | Initial FWD Collection Mass | Hardwood Total (g) | The total mass (bark and non-bark) of all hardwood fine woody debris collected on plots at the start of the experiment | | Initial FWD Collection Size | Plot | The plot ID number samples were taken from; these refer to the initial quantification of fine woody debris and not experimental plots | | Initial FWD Collection Size | Hardwood/Softwood | whether the fine woody debris substrate was hardwood (angiosperm) or softwood (gymnosperm) | | Initial FWD Collection Size | FWD Type | Whether the fine woody debris was bark or non-bark (twigs, small branches, etc.) | | Initial FWD Collection Size | FWD Weight (g) | mass of the fine woody debris substrate | | Initial FWD Collection Size | FWD Diameter 1 (cm) | The first measurement made on a piece of FWD to calculate average diameter. This measurement was done on one end of the FWD | | Initial FWD Collection Size | FWD Diameter 2 (cm) | The second measurement made on a piece of FWD to calculate average diameter. This measurement was done in the middle of FWD | | Initial FWD Collection Size | FWD Diameter 3 (cm) | The third measurement made on a piece of FWD to calculate average diameter. This measurement was done on the opposite end of FWD compared to Diameter 1 | | Initial FWD Collection Size | FWD Length (cm) | The length measurement of FWD | | Initial FWD Collection Size | Diameter 4 (cm) | The fourth measurement made on a piece of FWD to calculate average diameter. This measurement was only made on pieces that were not cylindrical in shape follow the same area as Diameter 1, but the piece was rotated approximately 90˚ | | Initial FWD Collection Size | Diameter 5 (cm) | The fifth measurement made on a piece of FWD to calculate average diameter. This measurement was only made on pieces that were not cylindrical in shape follow the same area as Diameter 2, but the piece was rotated approximately 90˚ | | Initial FWD Collection Size | Diameter 6 (cm) | The sixth measurement made on a piece of FWD to calculate average diameter. This measurement was only made on pieces that were not cylindrical in shape follow the same area as Diameter 3, but the piece was rotated approximately 90˚ | | Initial FWD Collection Size | Notes | Notes explain genereal information about pieces or why they may have extra measurements (Diameters 4-6) | | Monthly FWD Collection | Date | Date the FWD was measured | | Monthly FWD Collection | Plot | Plot the FWD was taken from | | Monthly FWD Collection | Softwood/Hardwood | Denotes whether FWD is softwood or hardwood | | Monthly FWD Collection | Bark/Non-Bark | Signifies whether FWD is catagorized as Bark or solid wood (branch, twig, etc.) | | Monthly FWD Collection | Size Class | Explains the general diameter of FWD. Class 1 ≤ 1cm; Class 2 = 1-3cm; Class 3 = 3-6cm, Class 4 = 6-9cm; Class 5 = 9-10cm | | Monthly FWD Collection | mass (g) | The mass of each piece of FWD collected after drying to a constant mass |
Methods
We measured site characteristics such as standing stocks of fine woody debris, leaf litter and litterfall. We then set up an experiment to test whether fine woody debris primarily serves as space or energy for leaf litter invertebrates and their function (decomposition rate). Litterbags were placed on plots, with standard substrates collected monthly for 7 months and natural substrates collected at the end of the experiment. Fine woody debris was either added as just space (synthetic fine woody debris) or just energy (ground fine woody debris). Leaf litter invertebrates were collected and identified at the end of the experiment. Chemistry measurements were analyzed for soils and initial chemistries of natural substrates. Data were collected from the field and laboratory components of the project.