RESUMO
Large cardamom (Amomum subulatum Roxb.) is an economically important cash crop that provides a livelihood option for the rural communities in Sikkim Himalaya. However, its production has declined drastically over the past few decades due to climate change and other factors affecting the livelihood of marginal cardamom-dependent farmers in the region. Climate change causes a shift in elevational distributions of mountain species, and it is pivotal to understand its effect on yield and yield-related traits for economically important plant species like large cardamom. For this, we randomly studied 41 large cardamom cultivation sites in Sikkim (India) with elevations ranging between 975 and 2069 m asl and evaluated the yield-related traits (number of capsules per spike, capsule length, capsule width, fresh capsule weight, dry capsule weight, number of seeds per locule, fresh seed weight, and dry seed weight) in five cultivars (Dzongu Golsey, Sawney, Seremna, Ramsey, and Varlangey). We observed a significant variability (P < 0.05) for morphometric traits in each of the five cultivars cultivated in different elevations. The cultivation of low-elevation cultivars like Seremna and Dzongu Golsey (suitable in elevation < 975 m) has shifted upward to mid (975-1515 m) and high-elevation (> 1515 m), while cultivation of high-elevation Ramsey cultivar (suitable in elevation > 1515 m) has shifted downward (< 1515 m). The Dzongu Golsey, Sawney, and Seremna cultivated in mid-elevation (975-1515 m) performed better in terms of yield-related traits than the same cultivars cultivated in high-elevation (> 1515 m) and showed moderate to high negative correlation between elevation and yield-related traits, indicating the negative effect of elevation on their yield. Likewise, Ramsey and Varlangey cultivated in high elevation (> 1515 m) performed better than the one cultivated in mid-elevation (975-1515 m) and depicted moderate to high positive correlation between elevation and yield-related traits, suggesting a positive influence of elevation on their yield. Although there is an elevational shift in the cultivation of large cardamom cultivars, the elevation influences the performance of the large cardamom cultivars, and it also suggests cultivating the cultivars in their suitable elevation range for better productivity.
Assuntos
Amomum , Elettaria , Siquim , ÍndiaRESUMO
The Khangchendzonga Landscape (KL), a part of 'Himalayan Biodiversity Hotspot', is known for its unique biodiversity assemblage. In recent years, the KL is experiencing threats to biodiversity due to the biological overdominance of native Maling bamboo (Yushania maling). In the present study, we investigated the impacts of the overdominance of Y. maling on the forest composition of Singalila National Park (SNP), Eastern Himalaya, India. Elevational habitats 2400 to 3400 m asl were sampled by laying 69 (10 m × 10 m) forest plots including 51 bamboo plots and 18 non-bamboo plots. Bamboo plots showed significantly (p < 0.05) low species richness and density in both shrub and herb layers which further manifested the low seedling density. Generalized Additive Model (GAM) estimated a significant (p < 0.0001) decline in species richness and density with increasing bamboo density in SNP. Our study projects the overdominance of Y. maling has a significant negative impact on forest structure and composition. Therefore, management of invasiveness of Y. maling is essential through its optimized removal from the protected areas and utilization in making handicrafts, paper industries etc. to create ecological and economic benefits. Further long-term studies assessing the impacts of Y. maling overdominance on forest ecosystems and soil dynamics are recommended.