The age of the DBH How much time tropical trees need to attain

1.3 m height

Simone Vieira (CENA)

Susan Trumbore (UCI)Plínio Camargo (CENA) Luiz Martinelli (CENA)

Diogo Selhorst (SETEM) Niro Higuchi (INPA)

Asner et al. 2005

Asner et al. 2005

Eco

syst

em

Fu

nct

ion

Time

Elasticity

Disturbance

Inertia

System stability

Function range

•Forest Structure and dynamics

•Age structure

Background

Precipitation

0

50

100

150

200

250

300

350

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Decmonth

mm

Manaus Rio Branco Santarém

2200 mm1900 mm

1960 mm

Differences between forests

Forest structure

0

100

200

300

400

500

600

10-30 30-50 >50

DBH Size Class (cm)

Ste

m h

a-1

Manaus Santarém Catuaba Humaitá

Manaus has more biomass overall, in smaller trees, than sites with a more pronounced dry season

Vieira et al., 2004

Manaus

DBH 10-30 cm33%

DBH 30-50 cm37%

DBH >50 cm

30%

Rio Branco

DBH 10-30 cm32%

DBH 30-50 cm24%

DBH >50 cm

44%

Santarém

DBH 10-30 cm26%

DBH 30-50 cm19%

DBH >50 cm

55%

Humaitá

DBH 10-3027%

DBH 30-5024%

DBH >5049%

Not all forests in the Amazon are alike

Site Stem/ha MgC/haManaus 626 180Santarém 460 141Rio Branco 466 95Humaitá 399 103

0

50

100

150

200

250

10-30a 30-50a >50a 10-30b 30-50b >50b 10-30c 30-50c >50c

DBH size class (cm)

Ste

m/h

a

0-5050-100100-300300-500>500

Age Class

Age structure simulated - Manaus

0.04cm/year 0.65* stdev

0.02cm/year stdev

0.02cm/year 0.65* stdev

Trees >300 years old50%

Trees >300 years old50%

Trees >300 years old45%

Vieira et al. 2005

0

50

100

150

200

250

10-30a 30-50a >50a 10-30b 30-50b >50b 10-30c 30-50c >50c

DBH size class (cm)

Ste

m/h

a

0-5050-100100-300300-500>500

Age Class

Age structure simulated - Rio Branco

0.04cm/year 0.65* stdev

0.02cm/year stdev

0.02cm/year 0.65* stdev

Trees >300 years old32%

Trees >300 years old38%

Trees >300 years old27%

Vieira et al. 2005

0

50

100

150

200

250

10-30a 30-50a >50a 10-30b 30-50b >50b 10-30c 30-50c >50c

DHB size class (cm)

Ste

m/h

a

0-5050-100100-300300-500>500

Age Class

Age structure simulated - Santarém

0.04cm/year 0.65* stdev

0.02cm/year stdev

0.02cm/year 0.65* stdev

Trees >300 years old18%

Trees >300 years old27%

Trees >300 years old17%

Vieira et al. 2005

Manaus

Santarém Rio Branco

Individuals/ha 626 460 466Biomass C MgC/ha 180 141 95Growth MgC/ha/yr 1.6-2.1 2.2 -3.0 3.3-3.4Mean age of C (yr)* 119 103 80 MRT of C (stock/growth)** 95 37 94 Mean Tree Age (yr)* 422 332 255* From monte carlo simulations **biomass-weighted Data from Vieira et al. 2004

C dynamics differ with forest location

• Radiocarbon and dendrometer based estimates of growth agree

• Big trees grow more rapidly than small trees

• Trees in Manaus (central Amazon) grow much more slowly than other areas

Field sites

• Terra firme forest• Oxisols (Distrophic and Eutrophic)• Variation in dry season length• Shortest in Manaus, longer in Rio Branco

(Catuaba and Humaitá), Santarém• Water Table – Deep (Manaus, Santarém)

– Shallow (Acre)

Sampling

• 2 plots by site (2.5 X 2.5 m)

• Recent gap and not recent gap

• All trees smaller than 10 cm DBH

• Tress with 1.3m heigth

• Radiocarbon dating – Base and DBH (center)

1.3m

0

100

200

300

400

500

600

700

800

900

1950 1960 1970 1980 1990 2000 2010

Time (years)

D1

4 C ‰

NH mean

SH mean

-30 to +30

No recent gap

0

2

4

6

8

10

12

Catuaba Humaita Manaus Santarém

Ste

m

>45

30 to 45

10 to 30

1 to 10

~ 14000 stem/ha

Recent gap

0

2

4

6

8

10

Catuaba Manaus SantarémStem

>45

30 to 45

10 to 30

1 to 10

• Although biomass may recover quickly through fast-growing pioneer species, slow growing species (therefore biodiversity) will take centuries to recover from disturbance

Implications of low growth rates: