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Harvard Forest Data Archive

HF276

Impacts of Climate Warming on Trophic Function at Harvard Forest and Duke Forest 2013

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Data

Overview

  • Lead: Shannon Pelini, Angus Chen, Justine Kaseman, Thomas Crowther
  • Investigators: Audrey Maran
  • Contact: Shannon Pelini
  • Start date: 2013
  • End date: 2013
  • Status: completed
  • Location: Prospect Hill Tract (Harvard Forest), Duke Forest (NC)
  • Latitude: +35.87 to +43.53
  • Longitude: -79.98 to -72.19
  • Elevation: 130 to 340 meter
  • Taxa:
  • Release date: 2016
  • Revisions:
  • EML file: knb-lter-hfr.276.2
  • DOI: digital object identifier
  • Related links:
  • Study type: short-term measurement
  • Research topic: physiological ecology, population dynamics and species interactions
  • LTER core area: organic matter
  • Keywords: arthropods, carbon, climate change, community structure, food webs, insects, soil respiration, trophic structure
  • Abstract:

    Forest floor food webs play pivotal roles in carbon cycling, but they are rarely considered in models of carbon fluxes, including soil carbon dioxide emissions (respiration), under climatic warming. The indirect effects of invertebrates on heterotrophic respiration through interactions with microbial communities are significant and will be altered by warming. However, the interactive effects of invertebrates and warming on microbes and heterotrophic respiration in the field are poorly understood. In this study we combined field and common garden laboratory approaches to examine relationships between warming, forest floor food web structure, and heterotrophic respiration. We found that soil animals can overwhelm the effects of warming (to 5 degrees Celsius above ambient) on heterotrophic respiration. In particular, the presence of higher trophic levels and burrowing detritivores strongly determined heterotrophic respiration rates in temperate forest soils, dictating the ecosystem response to warming. These effects were, however, context-dependent, with greater effects in a lower-latitude site. Without isolating and including the significant impact of invertebrates, climate models will be incomplete, hindering well-informed policy decisions.

  • Methods:

    Duke Forest Common Garden Experiment--Invertebrate

    Soil cores (~20cm diameter, organic layer) were collected from warm ant chambers at Duke Forest on 10 July 2013 and shipped to Harvard Forest, where macroinvertebrates (>1cm) were separated, recorded, and added to mesocosms (20 cm tall x 10 cm diameter PVC columns with rubber bottom cap and covered with black landscape cloth secured with rubber band). Mesocosms contained homogenized soils, with macroinvertebrates removed, collected near Harvard Forest warming chambers. Mesocosms were placed in Shaler basement wood shop. Experiment ran 17 July-19 August 2013. We measured leaf decomposition (round leaf litter bags course enough for invertebrate access on the topside; leaves were plucked and air dried from one Harvard Forest maple tree). Mesocosms were harvested at the end of the experiment and all living and dead invertebrate bodies were recorded. Respiration measurements were taken on a LI-6400 (LICOR, Lincoln, NE). Invertebrates were identified broadly into the following categories: spider, centipede, beetle larva morph 1, beetle larva morph 2, millipede, fly larva, caterpillar, earthworm, ant, leaf beetle, beetle. NA's represent missing or not relevant data.

    Harvard Forest Common Garden Experiment--Microbe

    Same as “Duke Forest Common Garden Experiment—Invertebrate”, but soil cores (~20cm diameter, organic layer) were collected from warm ant chambers at Harvard Forest on 1 June 2013. Invertebrates were not included in any mesocosms.

    Harvard Forest Common Garden Experiment--Invertebrate

    Soil cores (~20cm diameter, organic layer) were collected from warm ant chambers at Harvard Forest on 1 June 2013. Macroinvertebrates (>1cm) were separated, recorded, and added to mesocosms (20 cm tall x 10 cm diameter PVC columns with rubber bottom cap and covered with black landscape cloth secured with rubber band). Mesocosms contained homogenized soils left over from soil cores upon macroinvertebrate extraction. Mesocosms were placed in Torrey greenhouse. Experiment was moved on 25 June 2013 into Shaler greenhouse, where temperatures spiked, causing nearly 100 % mortality, thus ending the experiment. We measured leaf decomposition (round leaf litter bags course enough for invertebrate access on the topside; decomposing maple and birch leaf mix was collected near the warming chambers. Measurements as described in “Duke Forest Common Garden Experiment—Invertebrate.” Invertebrates were identified broadly into the following categories: beetle larva, beetle small ambrosia-like, beetle-rove, beetle-other, tiger beetle morph1, tiger beetle morph2, beetle black, beetle firefly, beetle-Japanese, beetle-weevil, spider-large, spider-medium, spider-small, spider-jump, hemiptera,ant- myrmica, ant-formica, ant- aphaenogaster, ant-tapinonma sessile, ant- temnothorax, ant-lasius, ant-camponotus, opilones (harvestman), homoptera (aphid), millipede, centipede, slug, caterpillar. NA's represent missing or not relevant data.

    Harvard Forest Field Mesocosm Experiment

    We filled mesocosms (19 L buckets, 30 cm diameter, 44 cm height) to 10 cm height with topsoil (O and A horizons, Canton loam) that we collected ~100-200 yards away from the chambers, from which we removed roots and macrofauna (e.g., beetles, ants, spiders, millipedes) via sieving (1mm mesh), and homogenized across all mesocosms. We had 5 treatments: 1: no fauna present; 2: only micro/mesofauna present; 3: only macroinvertebrates present; 4: micro/mesofauna and macroinvertebrates present; and 5: micro/mesofauna, macroinvertebrates, and a vertebrate predator present. We removed micro- (e.g., fungi, bacteria) and meso- (e.g., mites, springtails) fauna (Treatments 1 and 3) by autoclaving soil described above at 120°C for 30 minutes. We used red back salamanders (Plethodon cinereu) as the top predator in this experiment (Treatment 4). For treatments that included macroinvertebrates (Treatments 3 and 4), we used ~1.5 g each of live earthworms (Megadrilacea), a common invertebrate engineer and food source for salamanders, and mealworms (Tenebrionidae). Mesocosms were placed in the warm ants warming chambers (1.5-5.5 degrees C above ambient) at Harvard Forest Prospect Hill Tract.

    Into each mesocosm, we also installed a 10 cm diameter, 4.5 cm high, PVC collar, inserted approximately 1 cm into the soil. Within these collars we collected weekly soil efflux (RH) measurements using a LiCor 6400 (Lincoln, Nebraska). We counted and weighed all surviving macroinvertebrates at the end of the experiment. Mesocosms were present in the chambers for 6 weeks during June-August 2013.

    Within a few days of being placed in the field, micro/mesofauna removal mesocosms (Treatments 1 and 3) had dense surface fungal colonization while those with fauna (Treatments 2, 4 and 5) did not. We visually estimated the amount of fungal coverage in each mesocosm using a qualitative scale from 0 (no visible fungus) to 10 (no bare soil visible).

  • Use:

    This dataset is released to the public under Creative Commons license CC BY (Attribution). Please keep the designated contact person informed of any plans to use the dataset. Consultation or collaboration with the original investigators is strongly encouraged. Publications and data products that make use of the dataset must include proper acknowledgement.

  • Citation:

    Pelini S, Chen A, Kaseman J, Crowther T. 2016. Impacts of Climate Warming on Trophic Function at Harvard Forest and Duke Forest 2013. Harvard Forest Data Archive: HF276.

Detailed Metadata

hf276-01: Duke Forest common garden experiment -invertebrate

  1. date: date of CO2 efflux measurement
  2. week: week of the experiment
  3. tag: unique identifier number on metal tag attached to each decomposition bag
  4. efflux: soil efflux (μmol CO2 mol-1) measured using LI-6400 (unit: dimensionless / missing value: NA)
  5. temp: mean air temperature delta (difference between chamber and average of 3 ambient reference stations) of Duke Forest warming chambers between April 2010 and July 2013 from which soil cores/invertebrates were extracted (unit: celsius / missing value: NA)
  6. chamber: DF ant warming chamber from which the invertebrates originated
  7. subsample: A-D, from 4 opposite sides of each chamber
  8. mesocosm: identifier derived from chamber and subsample
  9. core.depth: depth of extracted soil core (unit: centimeter / missing value: NA)
  10. leaf.decomp: percent leaf mass lost from decomposition bag (unit: dimensionless / missing value: NA)
  11. invert.biomass.i: total mass of macroinvertebrates extracted from soil core and placed in mesocosm (unit: gram / missing value: NA)
  12. invert.abundance.i: total number of macroinvertebrate individuals extracted from soil core and placed in mesocosm (unit: number / missing value: NA)
  13. invert.richness.i: total richness, at a broad morphological/order scale, of macroinvertebrates extracted from soil core and placed in mesocosm (unit: number / missing value: NA)
  14. invert.biomass.f: total mass of macroinvertebrates that survived to the end of the mesocosm experiment (unit: gram / missing value: NA)
  15. invert.abundance.f: total number of macroinvertebrate individuals that survived to the end of the mesocosm experiment (unit: number / missing value: NA)
  16. invert.richness.f: total richness, at a broad morphological/order scale, of macroinvertebrates that survived to the end of the mesocosm experiment (unit: number / missing value: NA)
  17. microbial.biomass.c: microbial biomass (organic) carbon, using chloroform fumigation method in the lab of M Weintraub. TOC ug-C/g dry, calculated as difference between fumigated and K2SO4 extracted sample (unit: dimensionless / missing value: NA)
  18. microbial.biomass.n: microbial biomass nitrogen, using chloroform fumigation method in the lab of M Weintraub. TN ug-N/g dry, calculated as difference between fumigated and K2SO4 extracted sample. (unit: dimensionless / missing value: NA)
  19. spider: number of spiders extracted from soil core and placed in mesocosm (unit: number / missing value: NA)
  20. centipede: number of centipedes extracted from soil core and placed in mesocosm (unit: number / missing value: NA)
  21. millipede: number of millipedes extracted from soil core and placed in mesocosm (unit: number / missing value: NA)
  22. maggot: number of diptera larva extracted from soil core and placed in mesocosm (unit: number / missing value: NA)
  23. caterpillar: number of caterpillars extracted from soil core and placed in mesocosm (unit: number / missing value: NA)
  24. earthworm: number of earthworms extracted from soil core and placed in mesocosm (unit: number / missing value: NA)
  25. ant: number of ants extracted from soil core and placed in mesocosm (unit: number / missing value: NA)
  26. beetle: number of beetles extracted from soil core and placed in mesocosm (unit: number / missing value: NA)

hf276-02: Harvard Forest common garden experiment - invertebrate

  1. date: date of CO2 efflux measurement LI-6400
  2. week: week of the experiment
  3. tag: unique identifier number on metal tag attached to each decomposition bag
  4. efflux: soil efflux (μmol CO2 mol-1) (unit: dimensionless / missing value: NA)
  5. temp: mean air temperature delta (difference between chamber and average of 3 ambient reference stations) of Harvard Forest warming chambers between April 2010 and July 2013 from which soil cores/invertebrates were extracted (unit: celsius / missing value: NA)
  6. chamber: ant warming chamber invertebrates originated from at HF
  7. subsample: A-D, from 4 opposite sides of each chamber
  8. mesocosm: identifier derived from chamber and subsample
  9. core.depth1: depth of extracted soil core (unit: centimeter / missing value: NA)
  10. core.depth2: depth of second extracted soil core taken due to error in collection of first core. If core.depth2 is provided, this was the depth of the core used for the experiment, otherwise core.depth1 was used. (unit: centimeter / missing value: NA)
  11. leaf.decomp: percent leaf mass lost from decomposition bag (unit: dimensionless / missing value: NA)
  12. invert.biomass.i: total mass of macroinvertebrates extracted from soil core and placed in mesocosm (unit: gram / missing value: NA)
  13. invert.abundance.i: total number of macroinvertebrate individuals extracted from soil core and placed in mesocosm (unit: number / missing value: NA)
  14. invert.richness.i: total richness, at a broad morphological/order scale, of macroinvertebrates extracted from soil core and placed in mesocosm (unit: number / missing value: NA)
  15. beetle: number of beetles extracted from soil core and placed in mesocosm (unit: number / missing value: NA)
  16. spider: number of spiders extracted from soil core and placed in mesocosm (unit: number / missing value: NA)
  17. hemiptera: number of hemipterans extracted from soil core and placed in mesocosm (unit: number / missing value: NA)
  18. ant: number of ants extracted from soil core and placed in mesocosm (unit: number / missing value: NA)
  19. opilones: number of opilones extracted from soil core and placed in mesocosm (unit: number / missing value: NA)
  20. homoptera: number of homopterans extracted from soil core and placed in mesocosm (unit: number / missing value: NA)
  21. millipede: number of millipedes extracted from soil core and placed in mesocosm (unit: number / missing value: NA)
  22. centipede: number of centipedes extracted from soil core and placed in mesocosm (unit: number / missing value: NA)
  23. slug: number of slugs extracted from soil core and placed in mesocosm (unit: number / missing value: NA)
  24. caterpillar: number of caterpillars extracted from soil core and placed in mesocosm (unit: number / missing value: NA)

hf276-03: Harvard Forest common garden experiment - microbe

  1. date: date of CO2 efflux measurement
  2. week: week of the experiment
  3. temp: temperature of the soil at approximately 8 cm deep (unit: celsius / missing value: NA)
  4. tag: unique identifier number on metal tag attached to each decomposition bag
  5. chamber: HF ant warming chamber from which the invertebrates originated
  6. subsample: A-D, from 4 opposite sides of each chamber
  7. mesocosm: identifier derived from chamber and subsample
  8. core.depth: depth of extracted soil core (unit: centimeter / missing value: NA)
  9. leaf.decomp: percent leaf mass change in decomposition bag. Negative values indicate leaf mass was gained. (unit: dimensionless / missing value: NA)
  10. leaf.gain.loss: indicates if leaf mass was lost or gained
    • loss: leaf mass lost
    • gain: leaf mass gained
  11. microbial.biomass.c: microbial biomass (organic) Carbon, using chloroform fumigation method in the lab of M Weintraub. TOC ug-C/g dry soil, calculated as difference between fumigated and K2SO4 extracted sample. (unit: dimensionless / missing value: NA)
  12. microbial.biomass.n: microbial biomass nitrogen, using chloroform fumigation method in the lab of M Weintraub. TN ug-N/g dry soil, calculated as difference between fumigated and K2SO4 extracted sample. (unit: dimensionless / missing value: NA)
  13. efflux: soil efflux (μmol CO2 mol-1) measured using LI-6400 (unit: dimensionless / missing value: NA)

hf276-04: Harvard Forest field mesocosm experiment

  1. date: date of the of CO2 efflux measurement
  2. week: week of the experiment (e.g. week 1 is the first week of measurements)
  3. treatment: treatment for the mesocosm
    • IM: macroinvertebrates, microinvertebrates and microbes present (soil not autoclaved)
    • M: microbes and microinvertebrates (soil not autoclaved, no macroinvertebrates added)
    • S: salamander, macroinvertebrates, microinvertebrates and microbes present (soil not autoclaved)
    • SI: sterile soil with macroinvertebrates only (soil autoclaved)
    • SS: sterile soil (soil autoclaved, nothing added)
  4. chamber: HF ant warming chamber from which the invertebrates originated
  5. mesocosm: unique identifier for each mesocosm
  6. temp: average temperature over the course of the experiment for this mesocosm (unit: celsius / missing value: NA)
  7. warming: mean air temperature delta (difference between chamber and average of 3 ambient reference stations) of Harvard Forest warming chamber over course of experiment (unit: celsius / missing value: NA)
  8. sal.pa: salamander presence
    • 1: present
    • 0: absent
  9. invert.pa: macroinvertebrates presence
    • 1: present
    • 0: absent
  10. microbe.pa: whether or not soil was autoclaved to remove microbes and microinvertebrates
    • 0: soil autoclaved to remove microbes and microinvertebrates
    • 1: soil not autoclaved
  11. efflux: soil efflux (μmol CO2 mol-1) measured using LI-6400 (unit: dimensionless / missing value: NA)
  12. fungal.cover: fungus colonization of mesocosm. Qualitative scale from 0 (no visible fungus) to 10 (no bare soil visible)
  13. invert.mor: number of surviving macroinvertebrates/macroinvertebrate number added to mesocosm at start of experiment (unit: dimensionless / missing value: NA)