Comparative study on growth performance of two shade trees in tea agroforestry system

Area of Science:

• Agroforestry
• Ecology
• Forestry

Background:

• Tea agroforestry systems are vital for sustainable agriculture in regions like Barak Valley, Assam.
• Shade trees play a crucial role in the microclimate and productivity of tea plantations.
• Understanding the growth dynamics of dominant shade tree species is essential for optimizing system management.

Purpose of the Study:

• To investigate the annual stem girth increment of two dominant native shade tree species.
• To compare the growth performance of Albizia lebbeck and Albizia odoratissima across different girth size categories.
• To assess growth trends over a two-year period within a tea agroforestry system.

Main Methods:

• Established 52 sampling plots (0.1 ha) in the tea agroforestry system.
• Monitored trees exceeding 10 cm girth at breast height (1.37 m) from December 2010-2012.
• Categorized trees into dominant girth classes (30-50 cm, 50-70 cm, 70-90 cm) for increment analysis.

Main Results:

• Albizia lebbeck exhibited higher mean annual girth increment (e.g., 2.97 cm in 70-90 cm class, year 1) compared to Albizia odoratissima (e.g., 1.41 cm in 50-70 cm class, year 1).
• Albizia lebbeck consistently outperformed Albizia odoratissima in girth increment across all studied girth classes.
• Both species displayed similar growth trends over the two observation years, with significant differences in girth increment noted.

Conclusions:

• Albizia lebbeck demonstrates superior stem growth performance compared to Albizia odoratissima in this tea agroforestry context.
• The findings provide valuable data for selecting and managing shade tree species to enhance productivity in Assam's tea plantations.
• Continued monitoring is recommended to understand long-term growth dynamics and ecological impacts.