In this study, soil preferences of wild birdsfoot trefoil (Lotus corniculatus L.) and narrowleaf birdsfoot trefoil (L tenuis Waldst. & Kit.) species growing in natural flora of the Black Sea Region (Turkey) and the plant species which they interact with, as well as their feed values were investigated. Dominant forage species that interact with L. corniculatus and L. tenuis were determined by the visual estimation method at 126 and 86 locations, respectively, and also seed and soil samples from each location were collected. L. corniculatus preferred soils having higher lime (90.9 vs. 66.4 g kg-1, P=0.003), pH (7.41 vs. 7.14, P=0.001) and containing lower organic matter (20.0 vs. 26.8 g kg-1, P=0.001) compared to L. tenuis. L. corniculatus was neighbor to 89 different species (20.2% legume, 22.5% grass and 57.3% others), whereas L. tenuis was neighbor to 61 different species (41.0% legume, 19.7% grass and 39.3% others). The difference between two species in terms of the frequencies of neighbor plant families was significant (2=10.814, P=0.004). Dominant plant species growing in interaction with these Lotus species were Medicago lupulina, Trifolium pratense, Trifolium repens, Cynodon dactylon, Lolium perenne and Plantago lanceolata. Dactylis glomerata was also neighbor with high frequency to L. corniculatus. L. tenuis had high phosphorus, metabolizable energy and relative feed value, and lower acid and neutral detergent fiber contents. As a result, in the artificial pasture establishments or the improvement of natural rangelands, the aforementioned species growing in harmony in natural environment and exhibiting positive interaction with Lotus species studied should be preferred.