Desertification is a term used to explain a process of decline in the biological productivity of an ecosystem, leading to total loss of productivity. While this phenomenon is often linked of the arid, semi-arid and sub-humid ecosystems, even in the humid tropics, the impact could be most dramatic. Impoverishment of human impacted terrestrial ecosystems may exhibit itself in a variety of ways : accelerated erosion as in the mountain regions of the country, salinization of land as in the semi-arid and arid 'green revolution' areas of the country, e.g., Haryana and western Uttar Pradesh, and site quality decline-a common phenomenon due to general decline in tree cover and monotonous monoculture .of rice/wheat across the Indian plains. A major consequence of deforestation is that it relates to adverse alterations in the hydrology and related soil and nutrient losses. The consequences of deforestation invariably arise out of site degradation through erosive losses. Tropical Asia, Africa and South America have the highest levels of erosion. The already high rates for the tropics are increasing at an alarming rate (e.g., through the major river systems-Ganga and Brahmaputra, in the Indian context). due to deforestation and ill-suited land management practices subsequent to forest clearing. In the mountain context, the declining moisture retention of the mountain soils, drying up of the underground springs and smaller rivers in the Himalayan region could be attributed to drastic changes in the forest cover. An indirect consequence is drastic alteration in the upland-lowland interaction, mediated through water. The current concern the tea planter of Assam has is about the damage to tea plantations due to frequent inundation along the flood -plains of Brahmaputra, and the damage to tea plantation. and the consequent loss in tea productivity is due to rising level of the river bottom because of siltation and the changing course of the river system. The ultimate consequences of site desertification are soil degradation, alteration in available :water and its quality, and the consequent decline in food, fodder and fuelwood yields essential for the economic well-being of rural communities.
According to the passage, which of the following are the consequences of decline in forest cover?
Select the correct answer using the code given below.
The passage explicitly details several consequences stemming from a decline in forest cover. All four statements provided in the options are directly supported by the text.
1. Loss of topsoil: The passage states that deforestation leads to "adverse alterations in the hydrology and related soil and nutrient losses" and that consequences "arise out of site degradation through erosive losses." Erosion is the primary mechanism for topsoil loss.
2. Loss of smaller rivers: The text directly attributes "drying up of the underground springs and smaller rivers in the Himalayan region" to "drastic changes in the forest cover."
3. Adverse effect on agricultural production: The passage mentions "salinization of land as in the semi-arid and arid 'green revolution' areas" and "decline in food, fodder and fuelwood yields" as ultimate consequences of site desertification, which is linked to deforestation. A decline in food yields directly impacts agricultural production adversely.
4. Declining of groundwater: The passage refers to "drying up of the underground springs" due to changes in forest cover. Underground springs are manifestations of groundwater discharge, and their drying indicates a decline in groundwater levels or availability.
Since all four statements are identified as consequences of declining forest cover based on the passage, any option excluding one or more of these statements would be incorrect.