Home > GHCN > Olson Ecosystem Complex: Grilled Veggies

Olson Ecosystem Complex: Grilled Veggies

2010 March 28

Introduction

The GHCN station inventory includes two vegetative descriptions. The first is a two character marker stveg which is described as “general vegetation near the station based on Operational Navigation Charts; MA marsh; FO forested; IC ice; DE desert; CL clear or open;”. The second is grveg which is described as “gridded vegetation for the 0.5×0.5 degree grid point closest
to the station from a gridded vegetation data base.”
The gridded vegetation appears to have been is derived directly from the Olson World Ecosystem Complexes data.*

The Olson World Ecosystem Complexes data is available from the Carbon Dioxide Information Analysis Center at the Oak Ridge National Laboratories. The dataset has a long history with portions of it originating from a Jerry Olson project from 1970.
http://cdiac.ornl.gov/epubs/ndp/ndp017/ndp017.html

Methods

The Olson Ecosystem NDP data is available in two formats: a table formatted as an ARC/INFO interchange file (*.e00) and a long format where each row represents one lat/long cell (ndp017_g.dat). This later data file included the ecosystem label in the lat/lon row data. Since my toolkit does not yet include a utility for reading or converting the ARC/INFO interchange data, I wrote a custom Java data reader class for the long file. The data resolution is 30′.

The following is the Olson Ecosystem map that is included in the NDP017 dataset.

Results

Match between GHCN and Whiteboard station gridded vegetation types:
Match: 6885
Mismatch: 395
94.5% match rate

A new GHCN-type station inventory built using the Olson data set is available here: v2.olson.inv

A “stacked” comparison file is available here (the GHCN data is on the top line, my reproduction on the second): v2.compare.inv

In the following graph, the ‘white’ bar on top is the GHCN count for the vegetation type, the ‘grey’ bar is the count from the NDP Data Reader for the GHCN stations.

Olson Vegetation GHCN Count Whiteboard Count
ANTARCTICA 16 17
BOGS, BOG WOODS 19 19
COASTAL EDGES 127 131
COLD IRRIGATED 1 0
COOL CONIFER 363 365
COOL CROPS 380 376
COOL DESERT 81 82
COOL FIELD/WOODS 113 116
COOL FOR./FIELD 273 279
COOL GRASS/SHRUB 271 271
COOL IRRIGATED 36 40
COOL MIXED 162 155
EQ. EVERGREEN 50 46
E. SOUTH. TAIGA 12 12
HEATHS, MOORS 19 19
HIGHLAND SHRUB 127 128
HOT DESERT 161 156
ICE 8 9
LOW SCRUB 2 2
MAIN TAIGA 134 133
MARSH, SWAMP 60 60
MED. GRAZING 121 123
NORTH. TAIGA 64 63
PADDYLANDS 169 172
POLAR DESERT 7 5
SAND DESERT 41 42
SEMIARID WOODS 36 35
SIBERIAN PARKS 9 8
SOUTH. TAIGA 38 35
SUCCULENT THORNS 58 59
TROPICAL DRY FOR 107 104
TROP. MONTANE 61 62
TROP. SAVANNA 140 135
TROP. SEASONAL 108 109
TUNDRA 147 152
WARM CONIFER 63 61
WARM CROPS 967 979
WARM DECIDUOUS 149 144
WARM FIELD WOODS 305 302
WARM FOR./FIELD 381 386
WARM GRASS/SHRUB 592 600
WARM IRRIGATED 101 98
WARM MIXED 175 173
WATER 999 988
WOODED TUNDRA 27 29

Remarks

What’s there to say? While still working on mastering the DMSP/RC data, it was nice to find a dataset that instantly lined up with data in the GHCN v2.temperature.inv even if I had to write my own data reader to handle the columnar format of ndp017_g.dat. 95% match.

One small oddity is that the max length of the ecosystem labels were one character shorter than those in the GHCN inventory. I modified the affected labels as part of the data reader.

It seems unlikely that anybody is using the metadata components in the GHCN inventory that are unrelated to urbanity, population, and satellite brightness. I expect that v3 won’t include these at all.

Other Land Cover products are available, although the recent ones tend to be oriented more towards carbon cycles than the literal description of vegetation types. These include >Murai and Honda, NDVI and MODIS products.

References

Jerry S. Olson, Julia A. Watts, and Linda J. Allison, 1985, rev 2001Major World Ecosystem Complexes Ranked by Carbon in Live Vegetation: A Database, NDP-017 DOI: 10.3334/CDIAC/lue.ndp017

Holly K. Gibbs, 2006Olson’s Major World Ecosystem Complexes Ranked by Carbon in Live Vegetation: An Updated Database Using the GLC2000 Land Cover Product , NDP-017b DOI: 10.3334/CDIAC/lue.ndp017.2006

(A different Olson but a quick look into similar land cover data and its use)
RJ Olson, KR Johnson, DL Zheng, JMO Scurlock, 2001,Global and regional ecosystem modeling: Databases of model drivers and validation measurements, ORNL/TM-2001/196,

* Update: 2010 04 25
Peterson and Vose 1997 clearly state that Olson is used for the gridded vegetation filed (grveg)

Vegetation. If the station is rural, the vegetation for that location is documented. The classifications used on the ONC are forested, clear or open, marsh, ice, and desert. Not all ONC had complete vegetation data, so these metadata are not available for all stations. An additional source of vegetation data is included in GHCN metadata: the vegetation listed at the nearest grid point to each station in a 0.5° ´ 0.5° gridded vegetation dataset (Olson et al. 1983). This vegetation database creates a global vegetation map of 44 different land ecosystem complexes comprising seven broad groups. These metadata do not indicate the exact vegetation type at the station location, but they do provide useful information. In particular, an ecosystem classification can be used to some degree as a surrogate for climate regions since vegetation classes depend, to a large extent, on climate.

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  1. 2010 March 28 at 10:52 pm

    Another oddity – the station whose vege data I questioned in “Hand Grenades” thread, ADRAR, retains its unexpected reading: COOL FOR./FIELD

    10160620000 ADRAR 27.88 -0.28 263 264S 20FLxxno-9x-9COOL FOR./FIELD C
    10160620000 ADRAR 27.88 -0.28 263 264S 20FLxxno-9x-9COOL FOR./FIELD A

    P.S. Ignore the changes in the brightness data. Just experimentation at this time.

  2. 2010 March 29 at 1:17 am

    Cool,

    I’ve found some other neat products as well. I’ll shoot you a list when time permits.

  3. 2010 March 29 at 1:32 am

    neat stuff at sage,, especially for the usa

    Is there any way to get a simple file of GHCN id # and then the new vegatative type you compiled

  4. 2010 March 30 at 3:57 pm

    Cool thx

  5. 2010 March 30 at 10:45 pm

    I think you can see where I’m going with this. Eventually I will have a “v2.temperature.inv” built from nothing but published datasets for (hopefully) everything but station ids, lat and long. Indeed, input those three things, and you will be able to build a full station record for any set of coordinates.

  6. 2010 March 31 at 8:53 am

    Ron,

    Have you taken a look at impermeable surfaces by chance? I think it might be yet another urbanity proxy.

  7. 2010 March 31 at 2:58 pm

    Did you have a particular data set in mind?

    The SAGE data and NDVI products includes impermeable as part of its urban definition (Land Cover type 13).

    Also see here:
    http://neo.sci.gsfc.nasa.gov/Search.html?group=20

  8. 2010 March 31 at 3:56 pm

    Ron,

    I was thinking of http://www.mrlc.gov/nlcd_multizone_map.php for the U.S., but there might be something more up-to-date.

    I’ve been reaching out to a group at Yale that is working on measuring changes in urban form via remote sensing; hopefully they will have some good insights into the best datasets to use.

  9. 2010 April 3 at 10:48 am

    I am abjectly ashamed to reveal my ignorance but I am not a scientist and I haven’t got the foggiest idea what is being revealed here. But I think I really want to know.

    In the past two years vegetation, most noticeably trees, has been in rapidly accelerating dieback certainly on the US east coast and quite likely elsewhere. It is obvious to me in any cursory inventory that trees of every single species, whether old or young, are all terminally afflicted by exposure to toxic greenhouse gas emissions. They are losing limbs and bark, and falling over in droves.

    I am certain that this must be reflected in instruments such as satellite photos, because it’s perfectly plain to see from the ground that the volume of trees in the woods has decreased by close to 50% in some areas.

    Do you know of data that could measure this loss? I would appreciate any information you could provide me (in plain English!) that I can understand! Thank you.

    Gail (www.witsendnj.blogspot.com)

  10. 2010 April 5 at 8:15 am

    Gail, the original post here doesn’t help you much in what you are looking for, but its an interesting comment and request.

    What you are looking for might be NDVI data which shows changes in the reflectivity of vegetation over time. That’s what was used in the recent drought analysis in the Amazon, for instance. If the area is large enough, the die-off should show up by comparing sat data over the years. I’m working with some NDVI data now – but not in a time series. NDVI can be used to derive carbon production, land cover, leaf cover etc. I’ll see if I can dig up what you are looking for – but it might take a while before I get to it.
    http://neo.sci.gsfc.nasa.gov/Search.html?group=53

    However, I have to take exception to the phrase “toxic greenhouse gas emissions.” While greenhouse climate change could be driving changes in temperature and rainfall patterns detrimental to Eastern woodlands, CO2 and Methane etc are not directly toxic to trees.

    Warmer winters and lower rainfall, for instance, have helped pine beetle populations expand in the Rocky Mountains resulting in death of millions of acres of pine forest. Hopefully this winter included enough prolonged cold-spells to kill off some of the beetle population.

  11. 2010 April 5 at 8:16 am

    Greenhouse gas emissions aren’t toxic per se, at least in the concentrations we are discussing, and up to a point more CO2 will tend to benefit plants (some more than others). Its the secondary effects of GHGs (e.g. rising temperature) or tertiary effects (milder winters allowing pine bark beetles to survive the winter) that are problematic.

  12. 2010 April 5 at 4:25 pm

    No No No! I appreciate your responses and any help you find time to look at the satellite data. But greenhouse gases – not necessarily CO2 or methane, but the “other” greenhouse gases (nitrous oxide, sulphur dioxide, and acetaldehyde from biofuel emissions) are most certainly very toxic to vegetation when they mingle with UV radiation and form ozone. I should have made clear that it is those particular gases I was referring to – although a diet high in CO2 leading to increases in growth for trees seems more analogous to a human diet high in Big Macs and fries extra calories – leading to obesity, heart disease and diabetes…but that’s another story.

    There’s no question that ozone is toxic to vegetation, it has been shown to be true in many many scientific, peer-reviewed, published studies. Crop losses from around the world from ozone damage are estimated in the billions annually. Certainly rising temps and extreme variations in precipitation will be enough to kill trees as climate change progresses.

    Right now though, they are dying in droves from toxic greenhouse gas emissions that are the precursors to ozone – which in addition to damaging foliage directly, encourage insects and disease.

    The Amazon study is a curiosity. I suspect what may happen is that when trees die, more sunlight is let into the understory, and nasty vines quickly grow up on the tree trunks, thus making for the same reflectivity that the satellite pictures pick up. This is what I see happening in the dying woods in the US, and also what researchers on the ground in the Amazon documented.

    Thank you again for any thoughts you can add. If you are interested in documentation or links to research I would be happy to provide whatever I can.

    It’s quite critical that professional scientists that understand atmosphere physics, chemistry and biology begin to collaborate on this existential threat before widespread food shortages lead to famine, even here in the USA.

  13. 2010 April 5 at 9:53 pm

    Thanks for the elaboration, Gail. Zeke and I had obviously jumped to the wrong conclusion. The vines as a substitute for leaves is an angle I hadn’t thought of before. On the other hand, this is all new territory for me.

    A related paper (including CRU/GHCN surface records)
    Impact of vegetation types on surface climate change
    Lim, Kai, Calnay, 2006
    http://www.atmos.umd.edu/~ekalnay/climate_veg_JAMC06.pdf

    And one on deforestation (fires)

    Testing a MODIS Global Disturbance Index across North America
    David J. Mildrexler, Maosheng Zhao, Steven W. Running, 2009
    https://secure.ntsg.umt.edu/publications/2009/MZR09/Mildrexler_et_al_RSE_2009-Final.pdf

  14. 2010 April 6 at 3:04 am

    Great links, I will wade through them, thank you!

  1. 2010 April 25 at 9:26 am
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