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The key ecological concern in the basin is the loss of biodiversity due to habitat loss and degradation from sustained, extensive land use that changes natural wetland and river valley forests to farmland. Agricultural development has been responsible for most habitat losses in the Amur-Heilong River basin , particularly in the wetlands. The relatively small percentage of land occupied by farmland in the basin is somewhat misleading. The conversion of wetland to farmland happened first in the floodplain habitats along the rivers, thus claiming the most biologically productive areas with greatest species richness and importance.

In the Upper-Zeya, Zeya-Bureya, Middle-Amur plains, and Khanka Lake lowlands of Russia , 2.4 million ha of wetlands have been converted into arable land, hay fields, and pastures. The degradation of wetlands and human disturbance has caused declines in waterfowl nest productivity on the remaining small patches of wetlands around lakes and bogs. Additionally, at least three million ha of forest, mostly on the plains and along rivers, have been converted to farms. Such conversion has nearly come to a halt in the last decade due to crisis in agricultural production.

 

Crop production is also a problem in Mongolia , since it claims the most productive lands near water sources, and almost inevitably converts them into sands. The Mongolian Ministry of Nature and Environment inventory of the previously reclaimed 1.3 million ha of plowed lands showed that 585,000 ha are abandoned due to desertification.

Conversion of forests and wetlands to arable land is officially banned in basin provinces and is therefore no longer considered a major concern in China . However, it still occurs in many areas. Since 1958, the forest cover in Heilongjiang Province declined from 200,000 to 160,000 km².

The wetlands in the Song-Nen and Sanjiang Plains are endowed with highly fertile soils and other abundant natural resources such as extensive tracts of forest, grassland, and reed beds. They are naturally suited to agriculture, animal husbandry, forestry, and fisheries. In their pristine state, the Song-Nen and Sanjiang plains were mostly wetlands. They had an essential role in absorbing floods and sustaining low flows. Development in general and farming in particular reduced these wetlands considerably and, through fragmentation, reduced their capacity to absorb floods and to sustain low flows.

After 1949, the Sanjiang Plain wetland area decreased from 5.34 million ha to 1.48 million ha, and the cultivated area increased from 0.786 million ha to 4.57 million ha (Liu et al. 2004).

 

Wetland and Cropland Areas in the Sanjiang Plain (‘000 hectares)

	1949	1975	1985	1990	1995	2000
Wetlands	5,350	3,240	2,720	2,110	1,980	1,480
Croplands	780	2,050	3,490	3,600	3,740	4,570

Source: HEPB and Heilongjiang Research Institute of Environmental Protection. Environmental Impact Assessment of Integrated Agricultural Development and Environmental Protection Planning of Sanjiang plain. Harbin . 1996. 2000 figures from Liu et al. 2004.

 

Because of the sharp rises in grain prices that occurred in 2004-5 and due to renewed tax-exemptions and subsidies to grain producers, conversion of wetlands and other non-agricultural lands into croplands has recently become much more profitable than during the preceding five years. In 2002-2003 the attention of nature conservation authorities of Heilongjiang Province was focused on identifying farmlands that had been previously converted from wildlands and could be restored to wetlands and forests. From 2004 in many areas like Sanjiang National Nature Reserve the main concern was preventing further illegal conversion to cropland in small patches on margins of nature reserves. Increased incentives for crop and livestock production will also exacerbate water deficits in natural wetlands. Up to 250,000 hectares of new grain fields were reclaimed (or earlier reclamations “legalized”) in Heilongjiang province in 2004 (out of 2.2 million ha reclaimed nationwide in that year). Much of the new farmland was converted from floodplain wetlands.

 

Photo:

Once drained and plowed and then abadoned this land is unlikely to turn back into a wetland. Zeya-Bureya Plain. (Photo by E.Egidarev)

Also look:

Land-use trends:

General trends in land-use

Recent changes in land-use in three countries

 

Agricultural development in Eastern Mongolia