Effect of Amazonian Dark Earth on the composition, diversity and density of herbs, ferns, and palms.

Estela Maria Quintero-Vallejo1,2,3, Yannick Klomberg1, Frans Bongers1,Lourens Poorter1,2, Marisol Toledo2, Marielos Peña-Claros1,2 1 Wageningen University (WUR)2 Instituto Boliviano de Investigacion Forestal (IBIF)3 E-mail: estela.quinterovallejo@wur.nl

INTRODUCTIONAmazonian Dark Earth (ADE) or terra preta do indio is the name given to patches of black soils found in the Amazon region. These soils are associated to pre-columbian settlements, and are characterized by presence of pieces of ceramics and charcoal in the soil profile (Sombroek 1966). The fertility of these soils is high: compared with ultisols and oxisols that cover most of the Amazon region (Lehmann et al, 2003), and higher concentrations of charcoal and C are usually found on ADE soils (Glaser et al., 2003)

The effects of ADE on composition of palms and trees on secondary forest are recognized (Junqueira et al 2010), but the effects on understory community are still unknown. Given that distribution of species of Marantaceae, Arecaceae and ferns are correlated with soil properties as texture and nutrients, we wanted to evaluate the effect of ADE on the composition, diversity and density of understory herbs, ferns and palms.

METHODS•Twelve 27 (ha) at La Chonta forestry concession (Fig 1)• Soil sampling at 40cm depth on a 50X50 grid to make soil color maps (Fig 2).• Establishment of 44 transects (150x4m) in ADE and in adjacent soils non-ADE• Presence and abundance of all species of Marantacea, Arecaceae, Costaceae, Heliconiaceae ferns• Presence and abundance of Erythrochiton fallax, an understory shrub that produces dense stands at La Chonta• Measure of environmental variables such as canopy openness, tree and liana cover, and slope

IV from randomized values

Soil type

Species Family Observed indicator value (IV)

Average SD p

NADE Heliconia stricta Heliconiaceae 63.8

43.0 6.25 0.0050

NADE Attalea phalerata Arecaceae 52.0

32.2 6.86 0.0180

NADE Adiantum argutum Pteridaceae 36.4 16.3 5.73 0.0050 NADE Pteris propinqua Pteridaceae 47.0

30.1 6.01 0.0160

ADE Erythrochiton fallax Rutaceae 55.4

37.3 9.32 0.0420

RESULTS• ADE does not have effect on total diversity of species Fig. 3 • ADE has effect on fern diversity. We found more species of ferns on nonADE soils (Fig. 3). • Palms and other groups of understory community was similar on ADE and non-ADE soils • Species composition was very similar on ADE and non-ADE.• Four indicator species for non-ADE soils and one indicator species for ADE soils (Table 1). • Distribution of the common species in transects, such as Bolbitis serratifolia and Heliconia episcopalis seems to be driven by soils and canopy openness (data no shown).

Fig 1 Location of La chonta forestry consession (from Paz 2003)

Fig 2 Soil color map of one of the experimental (27 ha) plots of IBIF produced using the krigin interpolation function in ArcMap Note presence of ceramics and charcoal or both in some points (Klomberg Y., 2012 in prep).

Table 2 Indicator Species on ADE and non-ADE soils. Indicator species analysis: IV indicator value, SD standard deviation and Monte Carlo test with 1000 randomized trials. p represents the proportion of times that indicator value is equal or exceeded the observed value.

CONCLUSIONS

Amazonian Dark earth does not seem to have a strong lasting legacy on understory community after several centuries of forest regrowth.

Competitive exclusion driven by high fertility may explain low frequency of NADE indicator species in ADE areas. Likewise, human management of palms may also explain low frequency of Attalea phalerata on ADE sites

On the other hand, the ADE indicator species (Erytrhochiton fallax) may respond to the elevated nutrients in the Dark ADE sites. This clonal species can form dense stands in the forest that reduce understory light levels, and hence plant establishment.

Species area curves on ADE and non-ADE soils

0

5

10

15

20

25

30

35

40

1 3 5 7 9 11 13 15 17 19 21Samples

Spe

cies

ADE All species

NADE All species

ADE Ferns

NADE Ferns

ADE

NADE

Fig 3. Curves species area created using Stimates®. Dashed lines represent 95% confidence intervals of each curve

Erythrochiton fallax

Heliconia stricta

Photo J.C Licona

Attalea phalerata

Pteris propinqua

Adiantum argutum

AcknowledgmentsField assistants: Bruno Vaca, Lorgio Vaca, Ricardo Mendes, Rudy Payares. Student: Tjalle Boorsma. INREF, The Netherlands,

ReferencesJunqueira, A. B.; Shepard, G. H.; Clement, C. R., Biodiversity and Conservation, (2010) 19, 1933. Lehmann, J.; Kern, D. C.; Glaser, B.; Woods, W., Amazonian Dark Earths: Origin, properties, management, Kluwer Academic Publishers: Dordrecht, (2003). Paz-Rivera, C.; Putz, F. E., Biotropica, (2009) 41, 665. Sombroek, W. G., Amazon Soils, Wageningen, (1966)Glaser, B., Guggenberger, G., Zech, W., Ruivo, M.d.L. Soil Organic Matter Stability in Amazonian Dark Earths, in: Lehmann, J., Kern, D.C., Glaser, B., Woods, W.I. (Eds.), Amazon Dark Earths: Origin, properties, Management. Kluwer Academic Publishers, Dordrecht, pp. 141-158. (2003)