Silvopastoral Transformation of Desert Lands in the Caspian Sea Region

Abstract

The modern use of plain pastures in the Caspian Sea region is accompanied by deflation outbreaks affecting light soils; as a result, barkhan sands and slightly overgrown hilly sands are formed and the resistance of natural forage lands to deflation decreases. In the past century, afforestation amelioration was applied to such sands in dry subhumid areas of the Nogai steppe and they were transformed into silvopastoral lands with strip, narrow-belt, and diffuse layouts of the tree storey. The most commonly used afforestation amelioration technique involved the creation of black locust (Robinia pseudoacacia L.) and Siberian elm (Ulmus pumila L.) plantings and facilitation of their natural expansion. Silvopastoral lands form nontraditional, environmentally capacious, and sustainable landscapes that are attractive both as pastures for domestic animals and as wildlife habitats. This paper presents data on the state of forest stands, their productivity, structure, and nutritional value of forage produced on silvopastoral lands created on the Bazhigan sand massif and used for many years for unregulated grazing of bovine and small cattle. The studies were conducted in 2018–2021 using methods commonly accepted in forest inventory and geobotany. It has been established that at the age of 20–35 years, Siberian elm and black locust stands reach a height of 5.5–12.0 m and effectively protect soils from deflation and animals from overheating, and produce extra forage. Forage reserves in silvopastoral lands consist of grasses (mainly ephemerals) growing under the tree canopy, available woody greens whose nutritional value is not inferior to the nutritional value of predominant species in grass stands of natural pastures, and grazing phytomass in open areas. The total soil-feeding capacity of silvopastoral lands is up to 6 times higher than the soil-feeding capacity of natural pastures; furthermore, it is less dependent on weather conditions and makes it possible to increase the safe pasture load, grazing livestock numbers, and efficiency of grazing animal husbandry by 2–3 times. Taking the scientifically substantiated bovine cattle (BC) feed consumption norms per 1 kg of gain, on average, 100 ha of silvopastoral lands make it possible to additionally gain some 5 t of beef or an income of 750 000 rubles (at 2021 values).