These two sentences express very similar ideas. I am told that the second sentence is more likely to be the way a native Russian speaker would phrase the idea. I'm thinking that larches are more likely to be perceived as TYPICAL conifers in Russia and so the idea of a conifer shedding its needles probably seems normal from a Russian perspective. Whereas in the USA pines are the prototypical conifer and it seems like an unusual exception for conifers to shed their needles. So, my guess is that both sentences express reasonable propositions, but that assumptions are hidden in the word choice which reflect cultural expectations. Am I right and, BTW, are there any better or more likely ways of phrasing the basic idea?
Хотя хвойное дерево, лиственницы лиственные.
(Although a conifer, larches are deciduous.)
Лиственница это хвойное дерево, ежегодно сбрасывающее хвою.
(Larches are conifers, annually shedding their needles.)