In 2016 I pottered around Sulawesi setting up forest plots. The first results of which have been published in Biotropica (link to pdf below). The paper describes the tree flora of our sites in eastern Sulawesi.

The first site is Mount Tompotika, the highest point on the exposed central eastern peninsula. It’s a basalt mountain with cloud forest at about 500 m and an area of grassland and large boulders at a similar elevation. The surrounding foothills are ultramafic giving way to limestone.

The next location was Wawonii, a small island off Sulawesi’s southeastern peninsula – where despite some flooding (and Brexit and being knocked out of the footy by Iceland) we setup plots on sand and ultramafic soils. Ultramafic soils are heavy metal rich – see photo below of ultramafic rock.

The final sites were in Morowali Nature Reserve in the armpit of the central and south-eastern peninsulas where we established plots in the ultramafic foothills rising out of a large alluvial flatland.

Across six months I collected specimens which we shipped backed to the herbarium in Bogor. Duplicate specimens were then shipped on to Kew, where I was able to pick the brains of taxonomists – who pointed me toward decent species identifications.

It was hard to draw firm conclusions on how the environment shapes the flora with just our ten plots. However, the data we collected alongside other datasets should give us a chance to get to grips with how the environment affects tree communities in the Indonesian archipelago.

I’m enormously indebted to the many field guides I worked alongside – they made fieldwork both possible and a laugh.

The ms is here: trethowan_et_al_floristics_sulawesi

West Sumbawa

In 2018 Tim Utteridge and colleagues from RBG Kew, Herbarium Bogoriense, Universitas Nusa Cendana and Universitas Surya were awarded a NERC/Newton Fund grant to study Indonesia’s Lesser Sunda Island chain.

In October fieldwork got underway on the island of Sumbawa. The first target was the village of Mataiyang. Gateway to the largest tract of intact forest across the islands. One reason for this is it is honey country – locals rely on good quality forest for the product (which is delicious!!).

According to the maps these forests cover a largely mafic area north of a large copper mine. As we ascended and descended the rolling hills and ridges the large mafic boulders and low slung soils were reminiscent of the mafic Mount Tompotika on Sulawesi’s Central/Eastern peninsula.

We set up camp as darkness descended. We were a team of 13 by far the largest group I’ve entered a forest with (usually me and a couple of guides). With such large numbers, the issue we had at the campsite is the same issue that the plants have to deal with in these seasonal forests. Not enough water.

As we began to survey the forests the effects of the months of draught are clear. A rather stunted canopy around 10-12 m with occasional emergents reaching 30 m (rather similar to forests on the harsh soils of Sulawesi). It was also clear in the phenology, where individuals around the almost dry riverbeds were those in flower whereas in the interior flowers and fruits were rarely seen. Unlike the trees however we were able to up sticks and find a campsite with a plentiful water supply.

After 10 days in the forest I waved goodbye to the rest of the team from both Herbarium Bogoriense and the Indonesian conservation department (BKSDA) and returned to the forest to continue to pursue my main aim of setting up forest plots.

With the help of my four guides from Mataiyang, over the next three weeks we established plots at a far faster rate than I had been able to achieve in Sulawesi (less species, LESS RAIN). Other observations that marked these forests as different from Sulawesi were the occasional tree without leaves or with a spiny trunk.

Having finished in Mataiyang, the next stop was Pedauh nature reserve on the coast. Here I was joined by Dr Himmah Rustiami (who also joined me in Mataiyang) and Kew’s Dr Gemma Bramley and Dr Carmen Puglisi. The soils here were sandier and deeper than those inland. The canopy was still fairly stunted however, rarely reaching 20 m. Large diameter trees greater than 100 cm were more frequently seen. The presence of large Garcinia and Syzygium trees also marked these forests as different from those in Mataiyang.

We are indebted to Azim, Ghani, Jhon, Mus, Wira and Manunggal from BKSDA and Himmah, Debi, Gede, Mega and Wahyu from Bogor. Thanks go to Carmen and Gemma for putting up with their neighbours. Huge thanks go to Muis, Dola, Jaya, Suhar and Gepeng from Mataiyang.