पंजाब में हरिके आर्द्रभूमि को आधिकारिक तौर पर किस वर्ष रामसर स्थल घोषित किया गया था?

The transition zone between two distinct ecosystems is known as a/an:

The transitional zones or boundary regions between two diverse ecological communities are called:

The transition zone between two distinct ecosystems is referred to as: