Trees in autumn colors in Lazovsky State Nature Reserve, which is now considered one of the most important nature reserves in Russia. Boreal forest. Sikhote-Alin mountain ridge, Primorye region, Far East. Russian Federation. Forests in the temperate world experience a wide range of variability in temperature and precipitation. In regions where rainfall is broadly distributed throughout the year, deciduous trees mix with species of evergreens. Species such as oak (Quercus spp.), beech (Fagus spp.), birch (Betupa spp.), and maple (Acer spp.) typify the composition of the Temperate Broadleaf and Mixed Forests (TBMF).
Structurally, these forests are characterized by 4 layers: a canopy composed of mature full-sized dominant species and a slightly lower layer of mature trees, a shrub layer, and understory layer of grasses and other herbaceous plants. In contrast to tropical rain forests, most biodiversity is concentrated much closer to the forest floor.
TBMF are richest and most distinctive in central China and eastern North America, with some other globally distinctive ecoregions in the Caucasus, the Himalayas, southern Europe, and the Russian Far East.
Most dominant species have widespread distributions, but in many ecoregions there can be a large number of ecoregional and local endemics; beta diversity can be high for plants, invertebrates, and some smaller vertebrates in some ecoregions; unusual soils can harbor many specialist plants and invertebrates; some ecoregions can have very high alpha and gamma diversity for plants, particularly understory species and herbaceous floras. Altitudinal specialization occurs but is less pronounced than in the tropics.
Larger native carnivores require large natural landscapes to persist, periodic large-scale disturbance events such as fire necessitate the conservation of large blocks of forest; many species of plants, lichen, fungi, and invertebrates depend upon late-successional forests.
Sensitivity to Disturbance
Certain species are highly sensitive to habitat fragementation, such as breeding songbirds exposed to parasitism or elevated nest predation; many forest understory species are also unable to cross deforested areas; restoration potential for these forests is high; exotic species can have extensive and significant impacts on native communities; the loss of large native predators has many cascading impacts on forest structure and ecology.