Dear All,

A new version of the RAINFOR-GEM manual is now out and here is the link: http://www.tobymarthews.com/rainfor-gem-manual-v30.html (it'll move across to the permanent URL at http://gem.tropicalforests.ox.ac.uk/page/resources very soon).

I hope this is useful!

Best regards,
Toby

Dear All,

Measuring tree heights. About a week ago a CTFS paper came out about measuring tree heights by Markku Larjavaara and Helene Muller-Landau (see http://ctfs.arnarb.harvard.edu/Public/pdfs/Measuring%20tree%20height,%20a%20quantitative%20comparison%20of%20two.pdf ).

Apologies if other people have seen this before me, but I think it is important to stress that in RAINFOR we measure STEMLENGTH for our tree heights (see section 1.5 of the GEM manual) but in CTFS they measure vertical height to crown top. For leaning trees these are not the same so please don't use the methods proposed in that paper in RAINFOR-GEM plots (neither their tangent method nor their sine method).

Best,
Toby

Hi Jhon,
I put a schematic of the adapter ring in Appx. II of the RAINFOR-GEM manual (footnote, p.72). If you extract that image and blow it up, you get the attached. With that, you should be able to get an adapter ring made up in any workshop (best to take an SRC-1 with you to the workshop so that they can make it fit exactly).
Saludos,
Toby

After a meeting yesterday at the OUCE in Oxford, we all suggest to add a Replacement Rotation to the in-growth core protocol in the manual:

As has been discussed here before (Terhi, Chris and Dan Aug/Sep 2012: http://gem.tropicalforests.ox.ac.uk/postings?resource=ingrowth-cores ), over the course of time, in-growth cores become degraded: some soil is lost at each excavation and repeated searching through the core fragments the soil structure. So, we suggest to arrange a rotation so that 25% (i.e. 4 under the standard protocol) of the in-growth cores are replaced with new cores (at least 1 m away) every three months. At changeover, excavate the old core as before but discard the soil into the old core hole, dig a new hole and set up a new in-growth core there using the same cage. This has the added advantage of giving regular root stock data from new locations each time.

Does anyone have any comments about this new requirement? Is anyone already doing this? Any suggested modifications?

Toby

Dear All,

Just FYI: the journal Current Opinion on Environmental Sustainability has just published an issue dedicated to REDD+. The issue includes 17 review articles on REDD+ from different perspectives and disciplines. The overview article "Will REDD+ work?" is publicly-downloadable.

http://www.sciencedirect.com/science/journal/18773435/4/6

Toby

New GEM plots in Mato Grosso

The plots are located in the transition zone between Cerrado and Amazon Forest biomes, eastern Mato Grosso, Brazil. One plot was established in a cerrado stricto sensu (savanna) and other in cerradão (savanna forest). The study is conducted at Parque Municipal do Bacaba of the Universidade do Estado de Mato Grosso (UNEMAT), located in Nova Xavantina (14°42′S, 52°21′W) in partnership with Project PELD-Transição Cerrado Floresta-Amazônica (CNPq/Long-term Ecological Projects).

Bacaba park present different vegetation types (cerrado stricto sensu, cerrado rupestre, cerradão and gallery forests) which has been monitored since 1995. The basal area (~21 m2ha-1) and the mean heights (6.4 m) of the cerradão are greater than that of the cerrado stricto sensu (~15 m2ha-1 and 3.7 m). The most important species in cerradão are Hirtella glandulosa, Tachigali vulgaris and Xylopia aromatica, and in the cerrado stricto sensu are Qualea parviflora, Davilla elliptica and Roupala montana. The soils of both areas are acid (pH < 5.0) and dystrophic (Ca2+ < 0.4 cmolc kg-1) with high concentration of exchangeable aluminium (Al3+ > 1.3 cmolc kg-1). The soil fertility do not differ between the aareas. However, the cerradão soil showed higher percentages of clay than the cerrado at all depths up to 2 m, which could result in a higher availability of water throughout the year for the trees. The mean annual temperature is around 24.4°C and the mean annual rainfall is 1600 mm, with the dry season between May and September.

The fieldwork is leaded by Ben Hur Marimon-Junior, Beatriz Schwantes Marimon, Amintas Nazareth Rossete and Ricardo Keichi Umetsu (UNEMAT). The research goals are to understand the dynamic processes involved in the characterization and functioning of ecosystems in the transition between Cerrado and Amazon forest. We will install measurements for below-ground, above-ground NPP monitoring and also CO2 efflux measurements.

We are monitoring: litterfall, titter bag decomposition and release of nutrients, litter layer, soil moisture, soil density, penetrability and infiltrability.
We will install: ingrowth cores, total and component of soil CO2 efflux, stem CO2 efflux, foliage (leaf area index, LAI), dendrometers and coarse woody debris.

Hi Terhi, Good question about the ingrowth cores. There's certainly nothing magical about the 4 retrievals in my paper. If anything, it would be nice to have them in a bit longer (5, 6) just to reassure ourselves that the production in the 5th 3-month interval is similar to the first interval, which it should be if the soil fertility/texture change is not a big problem. It would be good to change holes every once in a while, the challenge then will be to align the production estimates from the old set of holes with the new ones (i guess there be some divergence just due to chance spatial variation). Maybe one way will be to have one overlapping period when both the new and old holes are running. This would then allow you to zero the production estimates from the new holes to the pre-existing time series from the old holes. This could be quite a lot of extra work, though you may only have to do it every year or few years, also you could perhaps just do it on a subset of the cores. Does that make sense?

Dear All,

You may be interested to know that there's now a spreadsheet on http://gem.tropicalforests.ox.ac.uk/page/resources (scroll down a bit) giving a full list of all equipment used in the RAINFOR-GEM plots along with potential suppliers and prices. It's up to date as of August although of course it will require updating from time to time.

If you have alternative suppliers or you have experience of some of these items and wish to say they are no good and propose alternatives, please post a comment on GEM http://gem.tropicalforests.ox.ac.uk/postings .

Best,
Toby

More photos of the Gabon team installing plots at Mondah

Hi Friends of Roots,

I think this is a good question: how long can we use an in-growth core? In Dan's paper (Metcalfe et al. 2008, Plant Soil) they installed cores and reported the results of 4 retrievals (=12 months) but there was no implication that that was the maximum lifetime of an IC core.

What is the longest amount of time a single IC core has been used and repeatedly excavated across the RAINFOR-GEM plots?

Toby

Dear Friends of Roots,

I have a question about in-growth cores. How long do you keep using the same soil and the same hole? I think the soil gets impoverished over time, when nutrients are removed along with the roots, and the texture might also change through the repeated searches. On the other hand, digging a new hole and establishing a new core every time is a lot of effort.

It would be great to hear you thoughts on this.
Cheers,
Terhi

The RAINFOR-GEM manual has had a write-up on the ECI website: check it out at http://www.eci.ox.ac.uk/news/articles/120622-rainfor.php (text courtesy Deborah Strickland).

Apologies for cross-posting: After much debate and revisions between here and Leeds, the new version (2.2) of the RAINFOR-GEM Intensive Plots manual has now been uploaded on a new subpage of http://gem.tropicalforests.ox.ac.uk/ (see "Resources" on the left).

This replaces the version 2.0 uploaded on GEM in February and also Dan Metcalfe's original v1.0 of the manual uploaded on http://www.geog.leeds.ac.uk/projects/rainfor/pages/manuals_eng.html (under “Measuring tropical forest carbon allocation and cycling”) and http://www.eci.ox.ac.uk/research/ecodynamics/carbon-balance.php (under “Online Materials” halfway down).

Hope this is useful for everyone!
Toby