Secondary forest

Gehring C, Park S, Denicha M. Liana allometric biomass equations for Amazonian primary and secondary forest. Forest ecology and management, 2004. 195 pp. 69-83. doi 10.1016/j.foreco.2004.02.054... 

Fig. 5. Sambucus javanica Reinw. ex Bl. From Plants of Indonesia. Bali Timur, karangasem. On skirt of Gunung Agung, 1-3 km of Besakih. altitude 1100 m, 8° 21 S -11 5° 26 E. in secondary forest. 

Fig. 93. Phyllanthus acidus. Forest Department herbarium, Brunei. Brun 5171. Geographical localization kedayan, Cheramai. Jalan Muara, South Lumut. In old, secondary forest. 2/3/1959. 

Troupin has also been reported . These alkaloids were found to exhibit antimicrobial and antiplasmodial activities. Epinetrum villosum is a twining liana, growing in secondary forests in the coastal areas in Congo and Angola and is used in traditional medical for the treatment of fever, malaria and dysentery . The genus Cissampelos contains cissampareine, which has potential medicinal uses, but it is also psychoactive. It is a principal alkaloid of dawidjiewortel (Cissampelos capensis), which grows in South Africa. 

The significant investment made in superficial roots by trees of Amazon forests is a clear indication of the importance of nutrient recycling from organic pools at the soil surface. However, research from the central and eastern Amazon has shown that trees in seasonally dry forests also have roots extending to at least 18 m depth (Nepstad et al. 1994). While the main function of these roots appears to be the uptake of deep soil water and groundwater, there is also potential for these roots to access deeper nutrient pools in the soil column. Nepstad et al. (this volume) elaborate on this issue by demonstrating that secondary forests growing in the eastern Amazon have P and K nutrient needs that cannot be satisfied by available stocks in the... 

Upper soil levels. They also show that secondary forests may re-establish deep root systems (6 m deep) within l6 years. They further show that abundant fine roots infected with mycorrhizal fungi characterize the deep roots of secondary forest. These circumstantial data suggest that secondary forests are mining nutrient reserves in deeper soils, but conclusive data are still unavailable. 

The secondary forest at Paragominas has recovered much of the net N mineralization capacity that is characteristic of primary forest, and the improved (reformed) pasture has higher net nitrification than the degrad-... 

Table 6.7 Mineralization indices and N trace gas emissions for soils from primary forest, secondary forest, reformed pasture, and degraded pasture at Fazenda Vitoria. ...

The monitoring of the soil plant available water (PAW) between 0 and 8 m depth in the soil has shown that during the dry season, in active B. brizantha pastures areas, a considerable use of water reserves occurs primarily in the top 2 m of soil. This is similar to observations made in primary and secondary forest areas. However, below 2 m, the depletion of the soil water reserves was greater in the forest ecosystem (Jipp et al. 1998). In general, active pasture ecosystems have a greater proportion of fine roots in soil layers between 0-2 meters, and the water in these layers is depleted more quickly, while a major part of the water reserve in the soil is stored in deeper layers. As the pasture... 

The progression of plant succession through the formation of "vegetation islands" and later secondary forest greatly changes the hydrological cycle at a local scale. This can be demonstrated by the similarity between the water depletion profiles obtained in secondary and primary forests Qipp et al. 1998). 

As abandoned pasture areas become increasingly invaded by shrubs and small trees, which in time lead to secondary forest formation, the biogeochemical cycles of plant nutrients and the hydrological cycle are expected, eventually, to resemble the cycles originally found in the primary forest. The rate of recuperation of biogeochemical cycles in secondary forests and the factors that influence those rates, however, deserve further attention. 

Lugo, A. E. 1992. Comparison of tropical tree plantations with secondary forests of similiar age. Ecological Monographs 62 1-41. 

Carbon content of biomass (primary and secondary forests) 0.5 Mg C (Mg biomass)" Idem 0.48 Mg C (Mg biomass) Carvalho et al. (1995)... 

Area of secondary forests 26 X 10 ha one-half of deforested area in 1996 (INPE 1998) 17.5X 10 ha Schroeder and Winjum (1995)... 

Feamside, P. M., and W. M. Guimaraes. 1996. Carbon uptake by secondary forests in BrazUian Amazonia. Journal of Forest Ecology Management 80 35-46. 

The Recovery of Biomass, Nutrient Stocks, and Deep Soil Functions in Secondary Forests... 

Our analysis focuses on three measures of secondary forest development biomass accumulation, nutrient accumulation, and hydrological recovery. We choose biomass accumulation, because it is the best integrative measure of secondary forest development, it is the basis for estimates of carbon sequestration by secondary forests, and it is the most frequently measured secondary forest parameter. An analysis of nutrient accumulation allows us to examine the commonly held assumption that nutrient shortages limit rates of secondary forest recovery (e.g. Gehring et al. 1999, Tucker et al. 1998). Although hydrological recovery in secondary forests is poorly documented in... 

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