Chronosequences

Baisden WT, Amundson R, Brenner DL, Cook AC, Kendall C, Harden JW (2002) A multi-isotope C and N modeling analysis of soil organic matter turnover and transport as a function of soil depth in a California annual grassland soil chronosequence. Global Biogeochem Cycles 16 1135. doi 10.1029/2001GB001823... 

Table 5. Inorganic N concentrations, mineralization and nitrification rates, and turnover rates ofNH% and NOJ in a chronosequence before and after forest clearing at Nova Vida, Brazil (after Neill et al., 1999).

The degree of transformation can be quantified analytically through the ratio of Fe in the oxides (commonly extracted with the strong reductant sodium dithionite (Fed)) to the total amount of Fe (Fct) and also by the ratio of Fe"/Fe ", because the iron located in the primary minerals of the parent rock is predominantly Fe". With age, the ratio Fea/Fct gradually approaches unity and the total Fe"/Fe " approaches zero (Leigh, 1996). Therefore, both can serve as an indicator of the maturity of a soil as a function of time (chronosequence) (e.g. Italy Arduino et al., 1984 Nepal Baum-ler et al. 1991, Spain Simon et al. 2000 USA Barret, 2001 Egli et al. 2001). The... 

Leigh, D.S. (1996) Soil chronosequence of Brasstown Creek, Blued Ridge Mountains, USA. Catena 26 99-114 Leland, J.K. Bard, A.J. (1987) Photochemistry of colloidal semiconducting iron oxide polymorphs. J. Phys. Chem. 91 5076-5083 Lengweiler, H. Buser.W. Feitknecht, W. 

Poage, M.A. Sjostrom, D.J. Goldberg, J. Chamberlain, C.P. G. Fumiss (2000) Isotopic evidence for Holocene climate change in the northern Rockies from a goefhite-rich fer-ricrete chronosequence. Chem. Geol. 166 327-240... 

Egli M, Mirabella A, Fitze P (2003) Formation rates of smectites derived from two Holocene chronosequences in the Swiss Alps. Geoderma 117 81-98... 

Marques, R., and J. Ranger. 1997. Nutrient dynamics in a chronosequence of Douglas fir (Pseudotsuga menziesii (Mirb,) Franco) stands in the Beaujolais Mounts (France). Forest Ecology and Management 91 255—277. 

Schlesinger, W. H. (1990). Evidence from chronosequence studies for a low carbon-storage potential of soils, Nature 348, 232-234. 

Figure 6.5. Changes in soil organic C storage and mineral content along a chronosequence in Hawaii (Torn et al., 1997). The substrate for soil development are basaltic ash deposits of known age. Climate and vegetation are virtually the same across the sites. (A) Soil organic C inventory versus ash substrate age. The solid line is the whole mineral soil to the C horizon, and the dashed line is the top 20 cm. The increase and subsequent decrease in SOM with soil age is mostly due to changes in the subsurface mineral soil. (B) The correlation of soil carbon in mineral horizons with the amount of noncrystalline minerals.

Haslam, S. F. I., Chudek, J. A., Goldspink, C. R., and Hopkins, D. W. (1998). Organic matter accumulation following fires in a moorland soil chronosequence. Global Change Biol. 4, 305-313. 

Dissolution of feldspars and hornblende is a slow process. If tunnels are formed by dissolution processes, laboratory experiments are not a promising tool to study the rate of tunnel formation. In that case, soil chronosequences can be of high value (Huggett, 1998). Tunnel formation has been studied in two chronosequences. 

Fig. 13.2. Fraction of tunnelled feldspars in the upper 2 cm of the mineral soil against soil age in two chronosequences. Data of the Michigan chronosequence is also corrected for the difference in feldspar content between the Mid-Sweden and the Michigan chronosequence, to get a measure for fraction of tunnelled minerals (grey dots) (modified from Smits et al., 2005).

In Michigan, feldspar content, as a fraction of total mineral content, is approximately half of that in the Mid-Sweden chronosequence. In contrast, the fraction of tunnelled feldspars in the Michigan chronosequence is twice that of the Mid-Sweden chronosequence. That could indicate that tunnelling is driven by nutrient demand. But, if the data are corrected for the difference in feldspar content, to get the fraction of tunnelled minerals, both curves match (Fig. 13.2). This suggests that feldspar tunnelling activity is independent of feldspar abundance, and could be determined by EM density. Indeed, a positive correlation was found between the frequency of tunnelled feldspars and EM density (Hoffland et al, 2003). 

Huggett, R. J. (1998). Soil chronosequences, soil development, and soil evolution a critical review. Catena, 32, 155-72. 

One of the first attempts to study soil nutrient dynamics under cultivated pastures in the Amazon basin was conducted in the early 1970s by Falesi (1976). The results of that chronosequence study in different soil types suggested that soil nutrient cycling in pastures differed from that of the traditional slash-and-bum agriculture. The decline in the levels of some nutrients in the soil was found to be more gradual, and the decline in productivity over time in planted pastures could, at least in part, be associated with the behavior of available phosphorus in the soil. 

Although the sampling methodology of Falesi s chronosequence study has been criticized (see Hecht 1982), other studies considering the dynamics of soil fertility in pasture areas in the Amazon basin found similar results (Diez et al. 1991, Hecht 1982,... 

Studying chronosequences of pastures in Para and Mato Grosso, Falesi (1976) found that the pH, ECEC, and base saturation of the topsoil remained elevated in all pastures. The... 

Piccolo, M. C., C. Neill, and C. C. Cerri. 1994. "Natural abundance of 15N in soils along forest-to-pasture chronosequences in the water Brazilian Amazon basin." Oecologia 99 112-117. 

Saldatriaga, J. G., D. C. West, M. L. Tharp, and C. Uhl. 1988. Long-term chronosequence of forest succession in the upper Rio Negro of Colombia and Venezuela. Journal of Ecology 76 938-958. 

Secondary forests accumulate biomass over time through the growth of woody plants. Biomass accumulation can be measured by monitoring permanent plots in secondary forests over a period of several years, or by using the chronosequence... 

Tyler, C., Mastronicola, T., and McGlathery, K. (2003). Nitrogen fixation and nitrogen limitation of primary production along a natural marsh chronosequence. Oecologia 136, 431—438. 

Figure 7 (a) Volumetric strain (szr.w) plotted against depth for soils on a marine terrace chronosequence on the... 

Baisden W. T. (2000) Soil organic matter turnover and storage in a California annual grassland chronosequence. PhD Dissertation, University of California, Berkeley. 

White A. F., Blum A. E., Schulz M. S., Bullen T. D., Harden J. W., and Peterson M. L. (1996) Chemical weathering rates of a soil chronosequence on granitic alluvium I. Quantification of mineralogical and surface area changes and calculation of primary silicate reaction rates. Geochim. Cosmochim. Acta 60, 2533-2550. 

T. (1993) Variations in weathering processes and rates with time in a chronosequence of soils from Glen Eeshie, Scotland. Geoderma 57, 275 - 293. 

Blum J. D. and Erel Y. (1997) Rb-Sr isotope systematics of a granitic soil chronosequence the importance of biotite weathering. Geochim. Cosmochim. Acta 61, 3193-3204. 

Dahms D. E., et al. (1997) Relation between soil age and silicate weathering rates determined from the chemical evolution of a glacial chronosequence comment and reply. Geology, 381-383. 

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