Geospatially Mapping Traditional Hawaiian
Cropping Systems Across the Pae ‘Āina
Natalie Kurashima
Cultural Resources Intern, Wahi Kūpuna Program
Kamehameha Schools, Land Assets Division
Society for Hawaiian Archaeology Conference 2012
Research Problem
• The known distribution of traditional agricultural
systems in Hawai‘i is incomplete
• Critical in estimating population, production,
carrying capacity, surplus; assessing societal
dynamics and sustainability indigenous
agriculture
Previous Study
• In 2009, Ladefoged et al.
modeled the two dominant
intensive traditional
agriculture systems in
Hawai‘i
• Assessed production, labor,
and surplus, which drove
sociopolitical dynamics
across regions
Objectives
• Extend GIS model, mapping the distribution and
production of the three main traditional Hawaiian
agricultural systems
• Include “colluvial-slope” agricultural system
• Inform management and restoration of traditional
agriculture today
GIS Model Parameters
Irrigated Pondfield, Lo‘i
Intensive system
Dominant cultigen: Taro
(Colocasia esculenta; kalo)
Dates to 1200 AD
Practiced at the largest scale in
Polynesia
Localities: flooded terracing (lo‘i)
in alluvial plains of windward
valleys
High initial labor inputs, but
substantial yields Figure 2: A pondfield system in Hanalei,
Kaua‘i.
1. Streams: buffered certain streams by 350 meters
2. Soil type: “Alluvium” + Colluvium (“Kl” series,
“colluvial land,” “stony colluvial land”)
3. Slope: 0 to 10 degrees
4. Elevation: 0-300 meters
Rain-fed Dryland Agriculture
Intensive system
Dominant cultigen: Sweet
potato (Ipomoea batatas;
‘uala)
Dates to AD 1400
Localities: mainly on leeward
areas of younger islands
Highly dependent and
bounded by rainfall
High labor inputs and lower
yields per unit area than taro Figure 1: An ariel photograph of the remnants of the
dryland field system in Kohala, Hawai‘i Island.
1. Slope: < 12 degrees
2. Elevation: 0-900 meters
3. Rainfall: 750-1600 mm/yr*
4. Substrate age: 4-700 ky old
5. Inland from the coast: > 100 meters
Dominant cultigens: dryland taro, sweet
potato, yams (Dioscorea sp.; ‘uhi), banana
(Musa hybrids; mai‘a), breadfruit
(Artocarpus altilis; ulu), olonā (Touchardia
latifolia), paper mulberry (Broussonetia
papyrifera; wauke), kava (Piper
methysticum; ‘awa), arrowroot (Maranta
arundinacea; pia), candlenut (Aleurites
molaccana; kukui), and ti (Cordyline
fruticosa; tī), ‘ape (Alocasia macrorrhiza)
Slope Agriculture
Extensive mixed cropping/arboriculture system
Probably developed as early as lo‘i, 1200 AD
Slope Agriculture
Localities: fertile lower slopes of
valleys on the older islands
Soil rejuvenation through fluvial
erosion and colluvial transport
Some initial labor requirements,
but low labor inputs and short
fallow
1. Soil type: “Alluvium” + “Old Alluvium” + Colluvium (“Kl” series, “colluvial land,” “stony colluvial land”)
2. Slope: < 30 degrees
3. Elevation: 0-900 meters
4. Rainfall: > 750 mm/yr
5. Extract Pondfield Area
Final Model
Ethnographic and Archaeological Accuracy
Figure 6: Comparison of (a) model results with (b) archeological evidence of the
Kalaupapa dryland field system (McCoy, 2007).
b) a)
b) a)
Figure 5: Comparison of (a) model results with (b) archeological evidence of pondfield agriculture in Hālawa Valley (Kirch and Kelly, 1975); evidence
of slope agriculture on the gentle slopes of the valley was also observed in the same study; c) a photograph of Hālawa today showing the valley’s broad
alluvial plain and gentle slopes.
c)
Moloka‘i
Figure 3 : Ethnohistoric distribution of Moloka‘i agriculture as
described by Lewis et al (1970).
Figure: 4: Distribution of population by district for 1853, ° = 20 people,
estimated by Coulter (1931).
Anahulu Valley
(Kirch and Salins, 1992: 50, Figure 2.12)
Ka‘ū Field System
“…most of the population dwelling in the windswept and
relatively dry coastal plains of Kau subsisted on the sweet
potato….most of the land, stretching for over 5 miles inland
from the coast over the districts named Kamaoa and Pakini,
was given over to sweet potato cultivation.” (Handy, 1940:
165-166)
O‘ahu
Discrepancies
Deforestation
o Movement of
rainfall
gradients
o Loss of fog-drip
inputs
Climate change
o Largest decline
of rainfall on
Maui
Conclusions
Conclusions
1. The model’s results correspond with ethnographic and
archeological evidence; discrepancies highlight land-
use change and climate change
2. The area of colluvial agriculture was large, 35% of
Hawai‘i’s total agricultural area
0
20000
40000
60000
80000
100000
120000
Kauai Oahu Molokai Lanai Maui Hawaii All islands
Area (ha) of Agricultural Systems by Island
Loi
Colluvial
Dryland
0
200000
400000
600000
800000
1000000
1200000
Kauai Oahu Molokai Lanai Maui Hawaii Allislands
Production (mt/yr) by Agricultural System
Lo'i
Colluvial
Dryland
3. Colluvial agriculture likely produced around 30%
of Hawai‘i’s food; higher on the older islands
o Further heightens the differences of agricultural
potential between older and younger islands
Production (All Islands)
Area
(ha)
Production
per area
(mt/ha/yr)
Production
(mt/yr) Percent of production
Lo‘i 12,883 25 257,354 24
Dryland 56,202 10 505,820 48
Colluvial 36,247 11 299,035 28
Total 105332 1,065,692 100
Conclusions
Conclusions
Labor (All Islands)
Area (ha)
Labor per area
(workers/ha)
Labor required
(workers/yr)
Average Annual Production per
Worker (mt/worker/yr)
Lo‘i 12,883 1.45 18,680 13.8
Dryland 56,202 2.9 162,986 3.10
Colluvial 36,247 1 36,247 8.25
Total 105332 217,912
12,912
39,557
5,283 306
33,663
126,191
217,913
0
50000
100000
150000
200000
250000
300000
Kauai Oahu Molokai Lanai Maui Hawaii All Islands
Labor Inputs (workers/year) by Island
Loi
Colluvial
Dryland
Conclusions
4. The pre-contact theoretical carrying capacity is
calculated as 1,270,000 people
Carrying Capacity
Caloric output (cal/100 g) Kcal Yielded (kcal/yr)
Carrying Capacity
(people/yr)
Percentage of Population
Fed
Lo‘i 145 373,598,840 341,186 27
Dryland 128 647,449,061 591,278 47
Colluvial 123 367,813,439 335,903 26
Total 1,388,861,339 1,268,367 100
400,000
242,000 262,160
142,050 130,313
300,000 250,000
800,000
1,270,000
0
200,000
400,000
600,000
800,000
1,000,000
1,200,000
1,400,000
King (1778) Bligh (1778) Youngson(1805)
Census(1823)
Census(1831-1832)
Emory Schmitt Stannard MaximumCarryingCapacity
Pe
op
le p
er
year
Authority
Various Population Estimates and Carrying Capacity
400,000
242,000 262,160
142,050 130,313
300,000
250,000
800,000
1,270,000
0
200,000
400,000
600,000
800,000
1,000,000
1,200,000
1,400,000
King (1778) Bligh (1778) Youngson(1805)
Census (1823) Census (1831-1832)
Emory Schmitt Stannard MaximumCarryingCapacity
Pe
op
le p
er
year
Authority
Various Population Estimates and Carrying Capacity
5. Lo‘i and colluvial systems are shown to have
much higher caloric efficiency than dryland
agriculture
Conclusions
Labor and Efficiency
Labor required
(workers/yr)
Average Annual Production per
Worker (mt/worker/yr)
Ratio of Carrying Capacity
to Labor
Lo‘i 18,680 13.8 18.3
Dryland 162,986 3.10 3.6
Colluvial 36,247 8.25 9.3
Total 217,913
Management Implications
• Strategic Agriculture Plan (SAP), Goal 3: “Restore
and revitalize traditional agricultural systems, lo‘i,
loko i‘a, and dryland field systems.”
• Cultural Resource
Management Plan (CRMP),
priority project: “Restoration of
Traditional Agricultural Systems”
• Model results can better direct and supplement
ethnohistoric and archaeological studies
• Inform Asset Managers about which areas are
environmentally suitable to grow traditional crops
o Suitability Analysis
Management Implications
• Dr. Patrick Kirch, UC Berkeley
• Jason Jeremiah, Kamehameha Schools
Mahalo to…
Contact Information:
Natalie Kurashima
