"I think that there are empty ecological niches in the literary landscape crying to be filled and when a book more or less fills a niche it's seized on, even when it's a far from perfect fit"

Edmund White's observation poignantly catches the dynamic and evolving nature of the literary world. By referencing "empty environmental niches", White draws a parallel between biological communities and the literary landscape, suggesting that both environments have chances or spaces that require to be addressed. In the context of literature, these "specific niches" could be interpreted as unique themes, narratives, or point of views that have not yet been checked out or fully realized in the literary market.

The expression "crying to be filled" implies an engaging need or a strong desire within the literary community or readers for new and varied stories. There is a hidden idea of eagerness and anticipation for development and creativity in literature. This can show shifts in cultural, social, or political climates that affect what readers seek in literary works. Perhaps there is a growing awareness or hunger for narratives that break conventional molds or check out underrepresented voices and experiences.

The latter part of the quote, "when a book more or less fills a specific niche it's seized on, even when it's a far from ideal fit", highlights how eagerly these niches are embraced, even if the literary works that emerge are not perfect or totally established. This highlights a possible desire amongst readers and critics to accept imperfections in favor of originality and novelty. It suggests that the value of fresh viewpoints and satisfying an unmet need can in some cases outweigh the requirement for a work to comply with conventional requirements of literary excellence.

White's quote, thus, can be viewed as a commentary on the transformative capacity of literature to adapt and react to the ever-changing requirements of its audience. It implies that the literary landscape remains in a state of flux, with spaces continuously opening and closing, which the literature that fills these spaces-- even imperfectly-- can catch the zeitgeist and resonate deeply with readers.