Plant Diversity and Vegetation Structures in the Understory of Mixed Boreal Forests under Different Management Regimes

Abstract

Researchers have extensively studied the effects of human disturbance, such as logging operations, on species richness. Typically the theme is the tree layer, and little is known about understory vegetation [1][2][3][4]. But in fact, understory species accounted for more than 90% of the richness in temperate forest vegetation [5,6], which was the main component of vegetation species diversity in this ecosystem. Although understory biomass is smaller than overstory biomass, the aboveground part of net primary productivity (ANPP) from understory biomass was more than half of the ANPP of the forest canopy in boreal forest vegetation [7]. Therefore, understory vegetation plays an important role in maintaining forest ecosystem structure and function [8].Pol. J. Environ. Stud. Vol. 25, No. 4 (2016), 1749-1757 AbstractCommunity surveys were performed in 30 forest stands with similar conditions under different management types in forests of northeastern China to study the influence of forest management on plant biodiversity. We evaluated this effect by calculating and analyzing species richness, vegetation structure, and aboveground biomass. Large variations in species composition, vegetation structure, species richness, and aboveground biomass were evident among the three types of common management types investigated (cut shrub tending, selective cutting, and understory planting). The species composition of the herb layer changed more than that of the shrub layer, and herbs were more vulnerable to impact from human activities. Each management type reduced the plant coverage, and this was most significant in planted plots. We found that in the cut shrub tending plots, the shrub height increased over time. The mean fresh weight of the control group was about 2 kg·m ). Our results also showed that management types in mixed forest stands strongly impact species diversity and, to some extent, environmental capacity, with negative effects on biodiversity.

Anthropogenic effect on forest landscape pattern and Cervidae habitats in northeastern China

“…Abundant water sources in the study area meant that water was not a limiting factor. The region's mixed broad-leaved and coniferous forests support more than 100 species of wild animals such as red deer, black bear (Ursus thibetanus) and lynx (Felis lynx) (Wu et al, 2016b).…”

“…This problem will become even more prominent with low deer population density in northeastern China. Many other factors also suggest that cervid populations in the Lesser Xing'an Mountains are probably low, such as habitat degradation (Wu et al, 2016b), disease and vehicle collisions, and damage to agricultural crops providing highly nutritious food for Cervidae.…”

Impacts of Changing Forest Management Areas on Forest Landscapes and Habitat Patterns in Northeastern China

“…With the planting of Schisandra chinensis, Panax ginseng and Auricularia auricula, an industry using products from the forest understory has gradually emerged in the local area. During the growing season of crops, diverse management techniques were usually implemented in the understory planting sites, such as weeding, fertilizing, pruning, and harvesting [8]. This policy improved the enthusiasm of local foresters and enriched the management pattern of understory planting, but increased the human disturbance.…”

“…There are now mainly three treatments in the forest management system applied in the study area, which include tending cut shrubs, selective cutting and understory planting. In general, studies have showed that the intensity of understory planting is the highest [8].…”

“…The main sources of human interference are forest management activities, which are represented by understory planting and intermediate cutting. Studies have shown that forest management activities could significantly influence the shrub and herb layers [8]. A variety of management measures and high intensity work in the understory will destroy the habitat essential for wild ungulates and is likely to have a negative impact on their population [9].…”