Step 1: Understanding the Concept:
Agroforestry systems are distributed across different ecological zones based on soil characteristics, temperature, and moisture availability.
Step 2: Detailed Explanation:
1. Prosopis species, particularly Khejri (Prosopis cineraria) and Prosopis juliflora, are extremely drought-resistant, deep-rooted phreatophytic trees.
2. In India, the Prosopis cineraria-based agrisilvicultural system is the traditional and most prominent agroforestry practice in the western desert plains.
3. This system is located in the arid and semi-arid tropics of Rajasthan, Gujarat, and Haryana, where the trees are integrated with dryland food crops (such as Pearl Millet/Bajra and cluster beans).
Step 3: Final Answer:
Prosopis-based agrisilvicultural systems are classically found in the Semi-arid and arid tropics.