With the above objective: the possibility of ameliorating latosols (see Chap. 1.1.4), there are certainly opportunities for the Amazonian population to benefit from research findings in this regard. The state of emergency of the people settled there was pointed out in Chap. 2.7. They often come from the arid Sertao of NE Brazil, are not used to the perhumid climate of Amazonia and are unaware of the limited cultivation options and the rapid exhaustion of slash-and-burn agriculture.
If there were the possibility of building up TP-like humus horizons in the long term through possibly also labour-intensive waste or compost management and moderate fertilization, constant and higher harvest yields could be achieved, as also achieved by the indigenous population (see Chap.1.1.4). Sales markets and infrastructure facilities that could be created in the process would offer the local population an improvement in the standard of living.
Figures about the population explosion - which cannot be contained with previous 'humane approaches' - are known (e.g. compared to today's 4.5 billion people by the year 2000 over 6 billion by 2100 9-15 billion people, according to UN projections and Frejka 1973, in von Loesch 1977, p.13). A further increase in agricultural yields in order to feed these people is not to be expected in the temperate latitudes: overbreeding of the species and the use of fertilizers can no longer be increased significantly! 'Further intensification of agriculture through increased use of mineral fertilisers, pesticides and machines is now proving to be economic nonsense' (Vester 1979, 8.136).
Other agricultural areas can no longer be developed.
Even with a - very unlikely - quadrupling of agricultural productivity, with the increase in population from 1950 to 2050, twice the usable agricultural area must be available (ca 1 or 2 billion ha; Goldsmith et al.1975, p. 117) !
It is therefore necessary to develop new agricultural areas. The semi-arid, peripheral and inner-tropical areas are suitable for this, especially Amazonia with the largest, previously 'unused' rainforest area on Earth.
If the proportion of people suffering from malnutrition today (10-50% of the world population, according to various estimates by the World Bank and the UNO, in Holenstein and Power 1976, p.57) or dying because of malnutrition (1-5%; ibid.p.61), do not increase extremely, these areas must be developed. According to Holenstein and Power, agricultural growth rates of 5%, which is greater than that of population growth, are allegedly achievable due to the production potential of smallholders with changed cultivation methods and changed ownership and capital relations (1976, p.105)!
There is not only the problem of the wrong, global and national food distribution (e.g. N-S gradient), which would have to be 'solved' politically, but also that of the effective global food deficit in future population figures!
A melioration of latosols should therefore be the focus of (soil) research. Amazonia can certainly represent an enormous agricultural potential.
Despite these considerations and the undoubtedly fascinating possibility of amelioration of the tropical rainforest area, it should not be overlooked that any human intervention in an ecosystem carries with it the danger of the collapse of this ecosystem, so that further human intervention is necessary on an ongoing basis to maintain the unnatural conditions against the forces of nature' (Atzler 1977, p.3).
'Increasing distance from natural conditions requires an ever more massive use of capital and work. ... (The) point beyond which irreparable damage occurs is reached in the tropical rainforest after a short time' (ibid.).
Such negative aspects of an agricultural valorization of the tropics or the Amazon region must be considered by scientists from a wide variety of disciplines when innovating new cultivation and soil improvement measures and may determine action! It does not apply to carry out what is technically or scientifically 'feasible' under all circumstances. There are enough negative examples of too far-reaching (scientific) research or its innovation from the recent past. Just think of genetic manipulation, nuclear research, oversized irrigation or dam construction projects.
The tropical rainforest of Amazonia represents the last, large, largely intact and undestroyed ecosystem on Earth.
The extent of the deforestation in the Brazilian Amazon region is not to be discussed here, which is undoubtedly due to the timber production (cellulose and wood fiber board industry, e.g. in the 30,000 square km large area of Ludwig (precious wood production), the partial industrialization (steel works and aluminum smelters; see Chap. 6.7 .5; power plant construction), traffic development (construction of the Transamazonica and other roads of 21,000 km length), the enlargement of pasture areas for cattle farming (currently, 56-72,000 hectares in particular are for cattle breeding projects for sale by the Brazilian government offered (Hb.f.Intern.Zus.arbeit 1981, IBrasso2, p.3) and the above-mentioned settlement of small settlers from the Sertão is strongly activated In contrast to all of the above, there was the earlier management form of shifting cultivation, which is very extensive (see Chap. 2.5.4), and only a low, earlier settlement density in the Amazon region (see Chap. 2.7).
Deforestation is already taking on extreme proportions: from 1966-1981 80,000 square kilometers (v.Conta 1981, p.102). Within a few decades, the rainforest ecosystem in Amazonia will be destroyed! There are estimates according to which 10% (Rohter 1979, S.A14) or even 24% of the original area of ??840,000 square kilometers are already 'lost' ( Council Env.Qual.1981, p.1380) or 0.5-1.5% of the rainforest every year (Woodwell 1979, p.16) or an area the size of Schleswig-Holstein every day (Brünig, in Dallibor 1981 ) is cleared. According to projections based on the current deforestation rate, there will be no more undisturbed forest in Brazil around 1990 (v.Conta 1981) or 2010 (Cauncil Env.Qual.1981, p.1380)! 'Agent Orange', known from the Vietnam War, has already been used for defoliation and clearing purposes in Brazil (Rohter 1979, p.A15).
Only in the case of smaller clearings is the primeval forest able, due to a regeneration system developed in the course of its evolution, to quickly close 'clearings and gaps that arise under natural conditions' or by humans, as in the case of slash and burn (see Chap. 2.5.4), in that 'fast-growing species with seeds that can survive a long time in the ground ... very quickly form a so-called secondary forest' (Beck 1974, p.48) .
Large-scale clearing is therefore associated with irreversible damage and losses.
Removing the dense vegetation cover leads to severe erosion with high leaching losses. Chap. 6.10-12 shows that the high level of leaching, particularly of the alkali and alkaline earth cations, can become a problem even in the case of dense forest cover in Latosol and TP. When the vegetation protection is removed, the insulation and thus the ground temperature increases sharply, all precipitation reaches the ground and is not largely reduced by evaporation as before.
The higher temperature in the soil as well as the higher precipitation reaching the soil cause even greater weathering, and thus greater desilification, Fe and Al oxide enrichment and the formation of laterite crusts (plinthic Ferralsol). The unbraked raindrops with their larger diameter in the tropics have a high kinetic energy (up to 10-3 mkp; Wilhelm 1972, p. 20 ), which increasingly loosen and erode the soil and in particular the humus-rich topsoil. High erosion losses are to be expected!
Since such vegetation cannot rebuild in the foreseeable future and in larger areas, the large-scale clearing is an irreversible development into a species-poor, anthropogenic savannah, similar to the camps that are already occurring there, for example near Santarem (see Chap. 2.5.5; Hueck 1966, p.26) or the Zona Bragantina or the Campos Cerrados (Hueck 1956, p.526; 1966, p.261ff.; Müller 1979), foreseeable and unstoppable!
In this context one speaks of a 'karstification' or 'steppe' of the primeval forest area, of a 'ghost landscape' (Rohter 1979, p.A15 ), a 'grass desert with rock-hard ground' (Rehm, in Lützenkirchen 1970, p. 8) or even the 'danger of a second Sahara looming : A wasteland with little vegetation' (Brinkmann, ibid.) !
Since there is neither transpiration nor retention, the runoff factor increases sharply: a contribution to increased surface leaching.
The first measurable consequences of this kind have already been identified in the Amazon lowlands: water level measurements in Iquitos registered that the height of the annual high water level has increased considerably since 1970, while the low water level has not changed (Suddeutsche Zeitung, 15.4.1981). Since the trend of increasing flood levels does not reflect a change in precipitation, but is a sign of higher runoff from the surrounding area, this confirms the above statement of reduced retention and increased leaching and siltation.
'Serious disturbances in the water balance as well as local and regional climatic changes with increasing instability of the annual precipitation course' (Kohlhepp 1978, p.9) are the result. In addition, this can lead to a drop in the groundwater level and to flood disasters!
Total evapotranspiration is reduced. The resulting lower relative humidity can, under certain circumstances, lead to a decrease in precipitation and thus further desertification of this and the adjacent areas, for example to an accentuation of the dry areas in Venezuela and NE Brazil.
In addition to these aspects of the hydrological and climatic changes in this large area, the fact of the destruction of a natural area with a previously ecologically intact, species-rich structure should be pointed out (see Chap. 2.5). This results in an irreversible loss of fauna and flora, but also of genetic resources that can be used to develop higher-yielding crops and species that are more resistant to diseases and pests.
Due to the new living conditions, there is not 'only' genocide for the native population, i.e. the destruction of their physical life, its extermination (see Chap. 2.7 and 1.5.2), but also ethnocide, i.e. the destruction of cultural independence and the downgrading of the natives to a sub-proletariat. In this context, the governor of Roraima should be quoted (in Schmidt 1981, p.2): 'A rich area like this cannot afford the luxury of preserving half a dozen Indian tribes, which in the end only hinders the development of the country ... '.
Negative consequences of large-scale deforestation there can also affect the entire world:
Tropical forests act as first-rate C-repositories through the strong C-bonds in the organic matter (over 20 kg C/qm in Amazonia). If larger amounts of it - mainly by burning the organic substance, but also by the subsequent oxidation of the humus layers - are released in CO2, which evaporates easily, this increases the global CO2 >-content of the atmosphere. Since 1850, the atmospheric CO2 content has increased from 290 to over 330 ppm as a result of the burning of fossil fuels through industrialization, but also through the clearing of large areas of forest (Woodwell 1979, p.11). In the trees, here especially in the tropical rain forests, about as much C is bound as in the entire atmosphere (Gosz et.al.1978; Woodwell 1979).
If the CO2 buffer and storage function is taken through the valorization of these areas, also of an agricultural or forestry nature (!), there is a further, very strong increase in global, atmospheric CO2 content (by 10%; Brünig 1974, p.407). Although its consequences cannot yet be estimated today, lasting effects on the global energy balance are to be expected (probably increased absorption of long-wave, infrared, terrestrial radiation and thus long-term warming, especially at the poles, and increasing desertification). From this point of view it is therefore 'important ... to oppose the depletion of the world's forests' (Woodwell 1979, p.11).
Another function of the tropical rain forests is their ability to photosynthesize, which produces O2 from CO2 through its assimilation and thus contributes to the oxygen balance of Earth.
When transformed into cultivation systems, more incoming light is reflected and less energy is absorbed on the surface (Brünig 1974, p.407). It is to be feared that with such dimensions, the albedo of the Earth and thus the energy balance and the climate of Earth will also change.
All such considerations refer to possible valorizations that are related to large-scale deforestation, regardless of whether it is large-scale cattle grazing, or as a result of industrialization or agricultural melioration methods, as was partly addressed in this work as a research goal (see Chap.1.1.4 and above) !
In general, and particularly in the tropical rainforest due to the vulnerability of the local ecosystem to degradation, human intervention in the eco-balance should only be undertaken where the natural balance has already been lastingly affected or destroyed by human intervention in the past.
In the Amazon region, this applies to all areas with a high colonization density and for those with a high level of timber exploitation.
Further research should be carried out for such a melioration, both analytically (investigations of the humus complex, nutrient binding, soil fauna) and in the field (pH increase, composting, mulching techniques, ethnological field research)!
In these regions, an attempt should be made to improve the living and survival conditions of the population by means of well-considered amelioration. However, ecologically intact areas should not be 'developed'! 'Primal ecosystems are declining, developed - and thus mostly destroyed at the same time - regions are being created in their place. The areas valuable not only for science but also for the preservation of life on Earth must be safe from this exchange.' (Beck 1974, p.48).
Despite all the arguments for and against the valorization of tropical, previous 'resource areas', be it large-scale or small-scale agricultural, it must not be forgotten that 'the rich white man' [from the industrial nations] often does not do it , to preach caution in the valorization of the rain forest, when clearing it is the key to material recovery [of the local. people and countries] (Turvey 1974, p.282). We, who really have to confess enough environmental sins in Central Europe, are basically not allowed to demand an 'ideal ecological world' in Brazil!
Last updates: 2007/2022