  Non-negative {\L}ukasiewicz paths are special two-dimensional lattice paths
never passing below their starting altitude which have only one single special
type of down step. They are well-known and -studied combinatorial objects, in
particular due to their bijective relation to trees with given node degrees.
  We study the asymptotic behavior of the number of ascents (i.e., the number
of maximal sequences of consecutive up steps) of given length for classical
subfamilies of general non-negative {\L}ukasiewicz paths: those with arbitrary
ending altitude, those ending on their starting altitude, and a variation
thereof. Our results include precise asymptotic expansions for the expected
number of such ascents as well as for the corresponding variance.
