school energy&environment

Plants of the taiga

This biome contains a high number of arboreal species: mainly firs (Abies and Picea), pine trees, birches, and fewer larches, willows, alders and poplars. The genus Picea consists of firs that can grow to an impressive size (over 50 m) and have a thick evergreen foliage; in Italy, we have Picea abies (or Picea excelsa), and many other species can be found everywhere in the Northern Emisphere (Eurasia and north-America). Like the Picea, also the genus Larix has also a circumboreal distribution (Eurasia and north-America), although in our regions it is represented by one species only, the larch (Larix decidua), which interestingly is the only conifer that sheds its leaves in winter (that’s where the name decidua comes from).
Evergreens prevail, partly because in this biome the summer season is short. These plants start their photosynthesis as soon as the temperature begins to rise in springtime and make the most of the feeble northern sun. Conifer needles are very good at capturing light. This is why the soil is dark and unsuitable for the undergrowth to develop. In addition, mounds of dead needles prevent herbs and shrubs from growing since they acidify the soil and replenish it of resinous substances. Only where the sun can seep in can shrubs with fleshy fruits grow, for instance currants, raspberries and blueberries. In addition, the aciform (i.e. needle-like) leaves of the conifers can tolerate the cold. In some areas, the taiga leaves room to sedges, rushes and graminaceous plants (perennial herbaceous species that love wet soil). In the moistest areas, there are mosses and liverworts and often sphagnum or peat mosses, which are responsible for the formation of peat-bogs.