Abstract
Silage serves as a cornerstone for the advancement of the livestock industry and a critical method for biomass preservation and utilization. This study investigated the impact of geographical and environmental factors—including longitude, latitude, temperature, relative humidity, precipitation, altitude, and sunshine duration—on fermentation parameters and bacterial communities in natural forage silage. Fresh samples of Saccharum arundinaceum and Leucaena leucocephala were collected from Changjiang, Haikou, Wanning, Danzhou, Qiongzhong and Sanya in Hainan Province, China. After 60 days of anaerobic fermentation, fermentation parameters and bacterial communities were analyzed. Results showed that fermentation parameters of the same plant exhibited significant variations across different regions. For instance, Leucaena leucocephala silage from Haikou showed the lowest pH value (4.32), while that from Danzhou recorded the highest pH value (5.63). In Saccharum arundinaceum silages, the prevalent genera in HGH (Saccharum arundinaceum silage from Haikou) were Weissella (49.85%) and Leuconostoc (20.42%), while the bacterial community of DGH (Saccharum arundinaceum silage from Danzhou) was dominated by Klebsiella (62.69%). These results revealed significant variations in fermentation characteristics and microbial community structure of the same plant species across different geographical regions. The Mantel-test network heatmap analysis demonstrated that longitude, latitude, altitude, precipitation, and relative humidity were identified as influential factors shaping silage microbial communities, with latitude being the most important geographical factor influencing silage microbiota. In conclusion, these findings highlight the critical need for region-specific adaptation of silage production strategies, particularly in response to latitudinal variations, to accommodate local environmental conditions, even when processing identical plant species.