Ecological Archives A025-006-A4
Elizabeth A. Law, Brett A. Bryan, Erik Meijaard, Thilak Mallawaarachchi, Matthew Struebig, and Kerrie A. Wilson. 2015. Ecosystem services from a degraded peatland of Central Kalimantan: implications for policy, planning, and management. Ecological Applications 25:70–87. http://dx.doi.org/10.1890/13-2014.1
Appendix D. Methods to model potential value of crops from smallholder agriculture.
Table D1. Classification and regression tree model specifications for crop yield, with explanatory variables selected including hydrology (hydro), the Euclidean distance from the major rivers (dist.), annual mean temperature (temp.), physiography (phys.), and (log)peat depth (log(peat)).
Crop |
Variables |
Number of terminal nodes |
Misclassification rate (%) |
Horticulture |
Hydro, temp, phys, log(peat) |
9 |
28 |
Rice |
Hydro, temp, phys, log(peat) |
11 |
18 |
Maize |
Hydro, dist, temp, phys, log(peat) |
15 |
29 |
Soy |
Hydro, dist, temp, phys, log(peat) |
14 |
29 |
Rubber |
Hydro, temp, phys, log(peat) |
10 |
35 |
Table D2. Crop revenue calculations. Maximum potential yield and price per ton were retrieved from FAOSTAT Production and Annual Producer Prices for 2008, available at http://faostat.fao.org/, accessed 1/6/2012). Revenue cost ratios were derived from the literature. For horticulture, we calculated the average maximum gross revenue for the horticultural crops listed in Table D3. Coconut yield was assumed to be 100% in areas in which it is currently grown, and zero otherwise.
|
Rice |
Maize |
Soy |
Horticulture |
Rubber |
Coconut |
Source |
Maximum potential yield (t/ha) |
5 |
4.24 |
1.35 |
17.92 |
0.71 |
6.55 |
FAOSTAT |
Price (USD/t) |
209 |
265 |
638 |
541 |
564 |
155 |
FAOSTAT |
Maximum gross revenue (USD/ha) |
1045 |
1124 |
861 |
7767 |
400 |
1015 |
Yield * Price |
Revenue cost ratio |
1.83 |
1.07 |
1.99 |
2.68 |
4.20 |
1.65 |
Rubber: Yamamoto and Takeuchi (2012) Coconut: Waney and Tujuwale (2002) Other crops: Jagau et al. (2008) |
Maximum net revenue (USD/ha) |
676 |
581 |
573 |
5656 |
323 |
632 |
Gross revenue – (gross revenue/(revenue cost ratio +1)) |
Table D3. Crops included in horticulture calculations.
Horticulture crops |
Bananas |
Green beans |
Cucumbers and gherkins |
Eggplants (aubergines) |
Mangoes, mangosteens, guavas |
Oranges |
Papayas |
Pineapples |
Tomatoes |
Watermelons |
Avocados |
Cabbages and other brassicas |
Carrots and turnips |
Cassava |
Chilies and green peppers |
Garlic |
Groundnuts |
Onions |
Potatoes |
Spinach |
Table D4. Crop contributions to each farming system (Jagau et al. 2008).
Crop proportion to revenue |
Potential net revenue if all crops had 100% suitability (USD / ha) |
||||||
Farming system |
Rice |
Maize |
Soy |
Horticulture |
Rubber |
Coconut |
|
Rice |
0.75 |
0.1 |
0.1 |
0.05 |
0 |
0 |
905 |
Rubber mosaic |
0.55 |
0.05 |
0.05 |
0.05 |
0.3 |
0 |
809 |
Rubber tree crop |
0.3 |
0 |
0 |
0.05 |
0.65 |
0 |
696 |
Coconut tree crop |
0.3 |
0 |
0 |
0.05 |
0 |
0.65 |
896 |
Literature Cited
Jagau, Y., M. Noor, and J. Verhagen. 2008. Technical report number 5: Agriculture in the Ex-Mega Rice Project area in Central Kalimantan.in Euroconsult Mott MacDonald / Deltares | Delft Hydraulics, editor. Master Plan for the Rehabilitation and Revitalisation of the Ex-Mega Rice Project Area in Central Kalimantan.
Waney, N. F., and J. Tujuwale. 2002. Traditional versus intensive coconut production in North Sulawesi. Sam Ratulangi University. Accessed June 2014 at http://www.stanford.edu/group/FRI/indonesia/research/coconutreport.pdf
Yamamoto, Y., and K. Takeuchi. 2012. Estimating the break-even price for forest protection in Central Kalimantan. Environmental Economics and Policy Studies 14:289–301.