According to a recent wildlife report, the biggest threat to the tiger's survival in Mudumalai Tiger Reserve (MTR) was found to be a small, beautiful flower, Lantana camara, a tropical American shrub, that invaded $40\%$ of India's tiger range. Tamil Nadu department's Lantana weed eradication drive helped to restore the dying MTR thereby also reducing human-wildlife conflicts. MTR is home to $25$ species of grasses and legumes.
Answer the given questions based on the information given above.
(a) Explain how did the removal of Lantana help in restoring the dying Mudumalai Tiger Reserve.
(b) Why is the invasion of Lantana camara a cause of concern in MTR.