7 g. The phenom enon of global w arm ing affect ing seasons and cult ivat ing process t hrough
rot at ional farm ing - t he villagers have discussed about shift ing t he cult ivat ion season and short ening t he period for grow ing seeds by one m ont h t o com ply w it h t he governm ent ’s
regulat ion of 100 days non-burning period.
B. Carbon stock accounting in rotational farming 1. Structure and succession rate of plant society in rotational field system
Based on t he dat a gat hered from sam pling plot of 8-year rot at ional age class syst em , it is found t hat aft er slash-and-burn, t he nat ural succession rat e is rat her fast . The regenerat ion of sapling
and young plant s is high during t he first t hree years. Alt hough in year one, none of t he t rees w it h diam et er larger t han 4.5 cent im et ers is ident ified, over 2,300 saplings per rai regenerat ed
from exist ing st em s and 1,981 young t rees are found. Inferior plant cover is w idespread w hich helps reduce t op-soil erosion in rot at ional field aged year one and t w o. In t he 3
rd
year, t he t ree cover is visible w it h larger t rees in succession of younger ones. The densit y of young t rees is
reduced. At t he age of 7-8, t he crow n and t op-soil cover are height ened as seen in Table 1.
Table 1. St ruct ure and Succession Rat e of Plant Societ y in Rot at ional Field
Rem arks: None of t he t rees w it h diam et er larger t han 4.5 cent im et ers is found in t he 1
st
year of rot at ional field.
Age Crow n
cover Soil cover
densit y of t ree t ree per rai
Succession Rat e of
Sapling per rai Succession
Rat e of Seeding per
rai Year 1
50-60 1,981
2,300 Year 2
NA NA
NA NA
NA Year 3
50-60 90-95
206 867
3,400 Year 4
70-95 90-100
100 1,531
6,800 Year 5
50-80 50-70
155 962
7,100 Year 6
NA NA
460 793
11,000 Year 7
60-70 70-80
460 560
3,900 Year 8
70-95 95-100
982 982
3,800
8
Figure1 : Tree densit y of size class
50 100
150 200
250 300
N o.
of T
re e
p er
R a
i
Size class by GBH cm.
Tree density of size class
year 3 Year 4
Year 5 Year 6
Year 7 Year 8
15 15-25 26-35
36-45 46-55
9 Pict ure: Carbon monit oring act ivit y in Baan M ae Lan Kham, Chiang M ai, Thailand IKAP
In reference t o t he graph, t he 2
nd
range of size class 15-25 cent im et ers is abundant in t he rot at ional fields of all age class as a result of succession of sapling in t he area. At t he age of 7-8
years, t he size of t rees found can be used for const ruct ion. The carbon can also be st ocked in t he form of w ood product s t o avoid t he burning of large w ood. The em ission of carbon from
rot at ional agricult ure can be reduced w it h t he effect ive t ree m anagem ent planning.
2. Amount of carbon storage in rotational cropping system
The dat a collect ion from t he plot indicat es grow t h size of t he t ree. This dat a is used in calculat ing and assessing t he am ount of carbon st orage in rot at ional fields of each age class
from year t hree onw ards. The t rees w it hin t his age class are adequat ely large for carbon calculat ion using algom et ric equat ion as elaborat ed in Table 2.
Table 2. Carbon st ock in rot at ional field
Rem arks: In rot at ional field of age class year 1-2, t he calculat ion is not possible because t he diam et er is less t han 4.5 cent im et ers.
Age class Area rai
Am ount of Carbon per rai t on
Carbon increment t on per rai per
year Tot al carbon st ock
t on 1 year
145 2 year
203 NA
NA NA
3 year 150
1.65 0.55
247.50 4 year
162 1.38
0.35 223.56
5 year 211
3.07 0.61
647.77 6 year
119 3.32
0.55 395.08
7 year 114
7.83 1.12
892.62 8 year
87 7.36
0.92 640.32
10
Figure 2. Carbon st orage in rot at ional field of different age classes
The st udy show ed t hat each age class of rot at ional field has diverse capacit y for carbon st orage. The rot at ional field of t hree years onw ards can be used in carbon calculat ion because t he
diam et er of t rees is larger t han 4.5 cent im et ers. The carbon st orage capacit y is divided int o 3 periods: for year 3-4 t he carbon st orage am ount ed t o 1.3-1.6 t on per rai; for year 5-6, 3.0-3.3
t ons per rai; and for year 7-8 t he carbon st orage capacit y doubled due t o t heir high grow t h rat e. The st ruct ure of t ree num bers and size class averagely increased t he annual carbon st orage of
1.02 t on per rai per year in t he rot at ional field. In com parison t o carbon em ission from slash-and-burn during t he plant ing season in 2013 in 87-
rai rot at ional fields aged eight years, 640 t ons of carbon w ere em it t ed in t he case of com plet e burning, t he w ood cannot be processed int o ot her product s. The rot at ional fields aged 3-7 years
can st ore an aggregat ed carbon of 572.69 t ons, excluding t he carbon in sm all t rees w it h t he diam et er sm aller t han 4.5 cent im et ers. The carbon em ission and st orage cycle in rot at ional fields
covers eight years t o m aint ain t he balance of carbon in it s int ernal syst em . M ore in-dept h st udy is required.
5 10
1 2
3 4
5 6
7 8
1.65 1.38
3.07 3.32
7.83 7.36
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Age of rotational field Amount of Carbon in Tree
Ton per rai
11
VI. Conclusions
To conclude, indigenous know ledge and pract ices on f orest land m anagem ent , such as rot at ional farm ing, have proven t o be sust ainable and in line w ith clim at e change adapt at ion and m it igat ion
st rat egies even t hough com m unit ies are not aw are or conscious of ‘clim at e change’ causes and effect s. Their t radit ional pract ices, based on t his st udy, have show n t o help m aint ain t he balance bet w een
carbon st orage and em ission from slash and burn farm ing.
A. Indigenous Know ledge IK and Local know ledge or LAAM As
In general, t he body of know ledge on ecology relat ed t o t he w ay of life of t he Pgaz K’ Nyau is a result of accum ulat ed experiences in ecological m anagem ent spanning several generations, and
ext ract ed in t he form of TajDuf const raining rules based on beliefs t hat regulat e t he relat ionship bet w een people and ecological syst em . Such rules guide t he people’s every life
pract ice in ut ilizing or t aking care of t he ecological syst em in a suit able and balanced w ays.. The belief t hat hum ans and nat ure have t o coexist wit h each ot her has been reflect ed in m any Pgaz
K’ Nyau sayings such as, “ t hose w ho follow t he rules ar e t hose w ho are free from danger.”
M eanw hile, Pgaz K’ Nyau w ho live in different ecological condit ions w ould assign t he significance of t he condit ion in different w ays. The rules and regulat ions have been based on t he
cust om s and t radit ions w hich serve as t he spirit ual foundat ion connect ing t o holy beings t hat
affect people’s life in every dim ension. To t hem , the cultural landscape w as designat ed as
sacred based on t heir pract ices and cult ural values. Consequent ly, t hey have est ablished rules and regulat ions adapt ed from t radit ions and cust om s t o cont rol, regulat e, and m anage it
t hroughout t he com m unit y’s hist ory. M ae Lan Kham com m unit y is est im at ed t o have been inhabit ed 300– 400 years ago. The t im e period is long enough t o assure t he sust ainabilit y of t he
sacred area. From t he perspect ive of carbon reduct ion, t he com m unit y’s m anagem ent of t he forest is very relevant . When t he forest is conserved, t he t rees release oxygen w hile absorbing
t he carbon dioxide. As long as t he forest exist s, t his chem ical process cont inues leading t o t he decrease of carbon em issions, event ually decreasing global w arm ing.
B. Carbon stock accounting in rotational farming
The rot at ional cropping w it h t he cycle of eight years is likely t o m aint ain t he balance bet w een carbon st orage in t he field for t he period of 3-7 years and carbon em ission from slash-and-burn.
The effect ive carbon m anagem ent such as t he use of w ood w it hout burning helps reduce em ission, leading t o carbon-balanced com m unit ies and st ock enhancem ent . The rot at ional
cropping field w it h carbon-balanced cycle m ust be prom ot ed. The challenge rem ains of how t he reduced cycle affect s carbon balance. The shift t o m onocult ure has not only led t o t he loss of
carbon balance but also ot her environm ent al problem s such as soil erosion, chem ical pollut ion in upst ream ecosyst em , loss of biodiversit y and local food plant species, et c. Therefore, t he
policies should priorit ize and prom ot e t he rot at ional cropping syst em m anagem ent , a sust ainable agro-forest ry t hat int egrat es local pract ices and cult ural dim ension.
