TemperateReefBase Geonetwork Catalogue
Light-driven tipping points in polar ecosystems - Casey Station, Antarctica
Some ecosystems can undergo abrupt transformation in response to relatively small environmental change. Identifying imminent "tipping points" is crucial for biodiversity conservation, particularly in the face of climate change. Here we describe a tipping point mechanism likely to induce widespread regime shifts in polar ecosystems. Seasonal snow and ice cover periodically block sunlight reaching polar ecosystems, but the effect of this on annual light depends critically on the timing of cover within the annual solar cycle. At high latitudes sunlight is strongly seasonal, and ice-free days around the summer solstice receive orders of magnitude more light than those in winter. Early melt that brings the date of ice-loss closer to midsummer will cause an exponential increase in the amount of sunlight reaching some areas per year. This is likely to drive ecological tipping points in which primary producers (plants and algae) flourish and out-compete dark-adapted communities. We demonstrate this principle on Antarctic shallow seabed ecosystems, which our data suggest are sensitive to small changes in the timing of sea-ice loss. Algae respond to light thresholds that are easily exceeded by a slight reduction in sea-ice duration. Earlier sea-ice loss is likely to cause extensive regime-shifts in which endemic shallow-water invertebrate communities are replaced by algae, reducing coastal biodiversity and fundamentally changing ecosystem functioning. Modeling shows that recent changes in ice and snow cover have already transformed annual light budgets in large areas of the Arctic and Antarctic, and both aquatic and terrestrial ecosystems are likely to experience further significant change in light. The interaction between ice loss and solar irradiance renders polar ecosystems acutely vulnerable to abrupt ecosystem change, as light-driven tipping points are readily breached by relatively slight shifts in the timing of snow and ice loss.
This archive contains data and statistical code for the article:
Graeme F. Clark, Jonathan S. Stark, Emma L. Johnston, John W. Runcie, Paul M. Goldsworthy, Ben Raymond and Martin J. Riddle (2013) Light-driven tipping points in polar ecosystems. Global Change Biology
Data and code are organised into folders according to figures in the article. See the article for a full description of methods. Statistical code was written in R v. 2.15.0. In data files, rows are samples and columns are variables. Details for numerical variables in each data file are listed below. Figures 7 and 8 were made in MATLAB and code is not provided.
Figure 1: rad_data.csv
Solar irradiance data derived from:
Suri M, Hofierja J (2004) A new GIS-based solar radiation model and its application to photovoltaic assessments. Transactions in GIS 8: 175-190.
Figure 2: Fig. 2c.1.csv
Light: Measured light at the seabed per day (mol photons m-2 d-1).
Figure 2: Fig. 2c.2.csv
Light: Measured light at the seabed per day (mol photons m-2 d-1).
Light.mod.p: Light at the seabed per day (mol photons m-2 d-1) predicted from modeled seasonal variation.
Figure 2: Fig. 2d.csv
Light: Measured light at the seabed per day (mol photons m-2 d-1).
Figure 3: Fig. 3a.csv
Irradiance: Mean irradiance (micro mol photons m-2 s-1).
P/R: Productivity/respiration ratios (micro mol photons O2-1 gFW-1 h-1).
Figure 3: Fig. 3b.csv
Light: Mean irradiance (micro mol photons m-2 s-1) in experimental treatments.
Growth: Thallus growth (mm) of Palmaria decipiens under experimental treatments.
Figure 3: Fig. 3c.csv
Des, Him, Irr, Pal: Ice-free days required for minimum annual light budget
Figure 3: Fig. 3c.bars.csv
Prop: relative cover (sums to 1 per site) of algae and invertebrates, excluding Inversiula nutrix and Spirorbis nordenskjoldi.
Figure 4: Fig. 4.csv
Time: months after deployment
Length: length of thalli (mm)
Figure 5: Fig. 5c and d.csv
Axis 1 and Axis 1: Values from first two axes of principal coordinate analysis
IceCover: proportion of days that each site is free of sea-ice per year.
Beta: Beta-diversity. Calculated as Jaccard similarity between the most ice-covered site (OB1) and each other site.
Figure 5: Fig. 5e and f.csv
IceCover: proportion of days that each site is free of sea-ice per year.
Value: number of species per boulder (for Metric=Diversity), or percent cover per boulder (for Metric=Cover).
Figure 6: Fig. 6a.csv
Sites.lost: number of sites removed from dataset due to sea-ice loss.
Ice: maximum ice-free days within the region (d yr-1).
S: Total species richness across each subset of sites.
Effort: relative sampling effort (number of sites sampled).
Simple
Identification info
- Alternate title
- Light-driven tipping points in polar ecosystems - Casey Station, Antarctica
- Date (Publication)
- 2013-07-04
- Edition
- 1
- Citation identifier
-
Dataset DOI
- Title
- Information and documentation - Digital object identifier system
- Date (Publication)
- 2012-04-23
- Citation identifier
- ISO 26324:2012
- Citation identifier
- doi:10.4225/15/51D4D578E62B3
Originator
Publisher
Principal investigator
Principal investigator
Principal investigator
Principal investigator
Principal investigator
Principal investigator
Principal investigator
Collaborator
Collaborator
Collaborator
Collaborator
Collaborator
Collaborator
Collaborator
- Name
- CAASM Metadata
- Status
- Completed
Custodian
- Topic category
-
- Climatology, meteorology, atmosphere
- Oceans
Extent
))
Extent
- Description
- Temporal Coverage
Temporal extent
- TimePeriod
- 1998-01-01 2008-12-31
- Title
- Light-driven tipping points in polar ecosystems.
- Citation identifier
- 19
- Citation identifier
- https://doi.org/10.1111/gcb.12337
Author
- Name
- Global Change Biology
- Issue identification
- 12
- Page
- 3749-3761
- NASA/GCMD Earth Science Keywords
-
- EARTH SCIENCE > ATMOSPHERE > ATMOSPHERIC RADIATION > SOLAR IRRADIANCE
- EARTH SCIENCE > BIOSPHERE > ECOSYSTEMS > MARINE ECOSYSTEMS > BENTHIC
- EARTH SCIENCE > CRYOSPHERE > SEA ICE > ICE GROWTH/MELT
- EARTH SCIENCE > CRYOSPHERE > SEA ICE > SEA ICE CONCENTRATION
- EARTH SCIENCE > CRYOSPHERE > SNOW/ICE > SNOW COVER
- EARTH SCIENCE > OCEANS > SEA ICE > ICE GROWTH/MELT
- EARTH SCIENCE > OCEANS > SEA ICE > SEA ICE CONCENTRATION
- EARTH SCIENCE > BIOLOGICAL CLASSIFICATION > PLANTS > MACROALGAE (SEAWEEDS)
- EARTH SCIENCE > BIOLOGICAL CLASSIFICATION > PLANTS > MICROALGAE
- EARTH SCIENCE > BIOSPHERE > ECOSYSTEMS > MARINE ECOSYSTEMS > COASTAL
- Keywords
-
- Irradiance
- Light
- Tipping Points
- NASA/GCMD Earth Science Keywords
-
- USIM > Underwater Spectral Irradiance Meter
- FLUOROMETERS
- PAR SENSORS > Photosynthetically Active Radiation Sensors
- NASA/GCMD Earth Science Keywords
-
- FIELD INVESTIGATION
- FIELD SURVEYS
- NASA/GCMD Earth Science Keywords
-
- AMD/AU
- AMD
- CEOS
- NASA/GCMD Earth Science Keywords
-
- CONTINENT > ANTARCTICA
- OCEAN > SOUTHERN OCEAN
- GEOGRAPHIC REGION > POLAR
Resource constraints
- Use limitation
- This metadata record is publicly available.
Resource constraints
- Access constraints
- licence
- Other constraints
- These data are publicly available for download from the provided URL.
Resource constraints
- File type
- Portable Network Graphic
- Title
- Attribution 4.0 International (CC BY 4.0)
- Website
-
https://creativecommons.org/licenses/by/4.0/legalcode
Legal code for Creative Commons by Attribution 4.0 International license
- Use constraints
- licence
- Other constraints
- This data set conforms to the CCBY Attribution License (http://creativecommons.org/licenses/by/4.0/). Please follow instructions listed in the citation reference provided at http://data.aad.gov.au/aadc/metadata/citation.cfm?entry_id=Light_Tipping_Points when using these data.
- Language
- English
- Character encoding
- UTF8
Distribution Information
Distributor
Distributor
Distributor
- Fees
- Free
- Planned available datetime
- 2013-07-04T00:00:00
- Units of distribution
- MB
- Transfer size
- 7.6
- Distribution format
-
- csv, r, word
- OnLine resource
-
GET DATA
Download point for the data
- OnLine resource
-
PROJECT HOME PAGE
Public information for ASAC project 2201
- OnLine resource
-
PROJECT HOME PAGE
Public information for ASAC project 2566
- OnLine resource
-
PROJECT HOME PAGE
Public information for ASAC project 2691
- OnLine resource
-
PROJECT HOME PAGE
Public information for ASAC project 2696
- OnLine resource
-
VIEW RELATED INFORMATION
Citation reference for this metadata record and dataset
Resource lineage
- Statement
- See the download document for details on methods used in collecting these data.
- Hierarchy level
- Dataset
- Maintenance and update frequency
- As needed
- Maintenance note
- 2013-07-04 - record created by Dave Connell from a template provided by Graeme Clark. 2013-08-12 - record updated by Dave Connell to alter the DOI format. 2019-01-15 - record updated by Dave Connell - basic updates.
Metadata
- Metadata identifier
- string/Light_Tipping_Points
- Language
- English
- Character encoding
- UTF8
Author
Sponsor
Owner
Type of resource
- Resource scope
- Dataset
Alternative metadata reference
- Title
- gov.nasa.gsfc.gcmd
- Citation identifier
- 028d582a-b3d5-4b67-8076-7ad44ec59c73
Alternative metadata reference
- Title
- gov.nasa.gsfc.gcmd
- Date (Last Revision)
- 2019-01-15T15:35:05
Identifier
- Description
- metadata.extraction_date
Alternative metadata reference
- Title
- gov.nasa.gsfc.gcmd
- Citation identifier
- 8.6
- Metadata linkage
-
http://data.aad.gov.au/metadata/records/Light_Tipping_Points
Point of truth for the metadata record
- Date info (Creation)
- 2013-07-03T00:00:00
- Date info (Last Update)
- 2019-01-15
Metadata standard
- Title
- ISO 19115-3
- Edition
- 2014
- Other citation details
- Version 1
- Title
- DIF to ISO 19115-1 Profile
Overviews
Spatial extent
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