ecology notes bI - Biology Junction
In either case, conifer leaves are compact. The compact form minimizes surface area and so reduces water loss. It also enables the leaf to bury its vascular tissue—through which water moves—in protective photosynthetic tissue. The cells that use sunlight are close to the surface, while the water-bearing cells are deep in the needle, keeping the precious liquid safe from evaporation.
This tutorial introduces plant reproduction
In the course of a growing season, many of those leaves will be torn by the wind, eaten by insects, pecked by birds, and colonized by fungi and bacteria. The overall leaf area is so much greater, though, that the short-lived leaves are still a good investment. Their photosynthetic capacity—that is, their ability to capture carbon and convert it to nutrients—is greater than that of the longer-lived coniferous leaves.
Whereas conifers invest in growing long-lived leaves, deciduous trees put their resources into creating more leaf area. Since they photosynthesize for only a short period, they must catch as much sun as they can during the months when they are in leaf.