Rubber

Hevea braziliensis, the source of Pará rubber, is one of the most ubiquitous trees in almost every place I have worked. It grows wild in the flooded forests of Peru where I was studying native fruits (see Regeneration Surveys, and Grias Predated), and was also quite common in the Dayak tembawangs of West Kalimantan (see Tembawang). Tapping the latex from these trees, whether cultivated or wild, provides an important source of income for rural populations throughout the tropics. [NOTE: The historical information about Pará rubber in the Wikipedia link is (embarrassingly) incorrect. Better to find a copy of J.W. Purseglove's Tropical Crops: Dicotyledons (ISBN 9780470702512) and read his thorough and extensive treatment of this important economic tree.]

Field Crews

In the early 1990's, I was involved with some extensive forest inventories in the northern part of Sanggau in West Kalimantan, Indonesia.  The sample area was kind of remote and hard to get to, and once you arrived, it was best to just camp out and finish the work.  Which is what three crews of local Dayaks, two cooks,  and I did for eight days. It only rained once. [NOTE: I remember one exceptional day we ran two kilometers of line through mixed Dipterocarp forest on terrain as flat as a football field.  The area, apparently, had never been logged and we didn't record a single stump.]  

Growth Rings

Because of the aseasonality of the climate in which they grow, the great majority of tropical trees do not produce growth rings.  The few species that do exhibit visible discontinuities in their secondary xylem have rarely produced these on a reliable, annual basis.  The lack of growth rings in tropical trees causes a lot of problems for ecologists and foresters. Foresters cannot easily determine how fast their trees are growing, and ecologists are left with no way of accurately determining tree age or reconstructing forest dynamics. 

Myrciaria dubia (see Camu-camu), a riparian shrub from lowland Amazonia, spends a large part of the year underwater. Once the floodwaters recede, the tree has three to four months to grow, flower, and fruit before being submerged again.  Not surprisingly, cross sections of the wood from this species (shown above) exhibit well-defined growth rings. And given that the Amazon River rises and falls only once a year, these growth rings are produced annually.

You can determine the age and growth history of Myrciaria dubia by counting rings and carefully measuring ring widths.  The species produces larger rings during years with low flooding (i.e. it is out of the water for a longer period of time), and smaller rings during years of heavy flooding. [NOTE: The trunk of a large adult may contain up to 40 years of floodpeak data].

Pneumatophores

Xylocarpus granatum, an important timber species in Papua New Guinea (see Palms of Kikori), develops an abundance of aerial roots called pneumatophores. We don't really know why some trees (e.g. bald cypress, mangroves) produce these things. Some researchers think pneumatophores help trees get oxygen in flooded environments; others suggest that these aerial roots provide stability and structural support in mushy soils.  All I know is that they make walking through the forest extremely tricky when its flooded (see Wet Feet). [NOTE: The fact that  a tree doesn't die after its pneumatophores are removed would suggest that the stability in mushy soils hypothesis provides the most reasonable explanation for these structures].

Street Food in Chetumal

The city of Chetumal in Quintana Roo, Mexico is the entry point to the Selva Maya (see Selva Maya, Selva Maya II, Selva Maya III, and Selva Maya Interrupted).  Lot of delicious food available on the street at night.  The elotes smeared with mayonaise, queso fresco, and chili powder are my favorites. [NOTE: In spite of what the lady said, the chili habanero powder was - of course - killer hot.]

Jungle Gym

This is pretty self-explanatory. A group of Dayak kids from the village of Tae in West Kalimantan climbing up the trunk of an illipe nut tree (see Illipe Nut, Illipe Nut II, and Illipe Nut III) in one of the local tembawangs (see Tembawang). [NOTE: The young man on the left in the brown shirt is Susanto, who worked in the camat's office in Batang Tarang and helped a lot with the research in Tae (thx Susanto)]

Where'd all those durian trees come from?

Simple question with, in this case, an obvious answer.  The image below was taken behind a small lean-to ("pondok") in a managed forest orchard (see tembawang) in Bagak, West Kalimantan (see Bapaks from Bagak) during durian season. Villagers would stay in the orchard all night picking up the durian fruits that had fallen - and eating a large number of them. They'd throw the woody husks and seeds into a heap behind the pondok.

The next photo was taken behind the pondok a year later.  Every one of the plants shown in the foreground is a durian seedling. These will be selectively weeded every couple of years, and, eventually, at least one of them will make it up to the canopy and start producing fruit. [NOTE: There were dozens of pondoks scattered throughout the tembawangs of Bagak during durian season.  A wonderful place to spend an evening regenerating the forest].

Climbing on the Ponies

Happens all over the world.  Even with priceless ancient statues. Two little boys climbing on the carved horses at a Buddhist shrine in Kathmandu. The stone saddles on the horses were worn smooth from constant use.

Wet Feet

During the forest inventory work at Kikori (see Living on a Log Raft and Chain of Custody), the tide would occasionally catch us in the middle of a transect and we had to count and measure trees in water up to our waist.  The villager on the left is estimating tree height with a clinometer, while his colleague on the right has measured back 20 meters from the sample tree with a fiberglas tape. Kind of fun, actually, although I always worried about snakes. [NOTE: The main problem was keeping my camera out of the water.  Most of the time, it and the clipboard with the tally sheets were balanced on top of my head].

Chain of Custody

All the logs that came into the mill at Kikori (see Living on a Log Raft and Palms of Kikori) had to be labeled with a code showing the species, the felling cycle/date, and the site of origin. This was done to insure that the communities weren't cutting more than they should, i.e. that they were only harvesting the annual growth of merchantable timber in their forests. This type of log labeling represents one step in the chain of custody process required for forest certification by the Forest Stewardship Council.