Anthropogenic and climatic‐driven peatland degradation during the past 150 years in the Greater Khingan Mountains, NE China

Abstract

Relationships between modern pollen, climate, and human activities are important for improving the explanation of fossil records. To better understand anthropogenic and climatic impact on peatland vegetation and environment, we assessed the impact of the human influence index (HII) on modern pollen assemblages from 61 surface soil samples (different land-use types) in the Greater Khingan Mountains by using detrended correspondence analysis and redundancy analysis. Based on the palynological analysis, 210 Pb age-depth model, and weighted averaging partial least squares, we reconstructed HII values of Tuqiang peatland in the Greater Khingan Mountains during the last 150 years. The reconstructed HII values demonstrated that the intensity of human activities increased gradually before 1900 AD, when the population of Heilongjiang Province was less and its native inhabitants continued to hunt and gather. During the period of 1900-1950 AD, human influence intensity increased sharply and reached peak values. Wars and placer gold mining caused large numbers of people immigrated north to Heilongjiang Province, rapid population growth strengthened the human impact intensity. In addition, invaders exploited the forest resources without limit. Widescale deforestation and land reclamation destroyed vegetation landscape and reduced forest coverage seriously, which led to soil erosion and land degradation. With the foundation of new China (1949 AD), the implementation of forest protection policies clearly reduced the human disturbance intensity.

Hydroclimate Changes Based on Testate Amoebae in the Greater Khingan Mountains’ Peatland (NE China) during the Last Millennium

“…A. muscorum and A. militaris are species related to dry peat surface conditions [69]. Fossil pollen records from the TQ peatlands show that the expansion of birch forests over the last hundred years indicates that the climate of the Greater Khingan Mountains became warmer and drier [70]. The sedimentary record from the MTL peatland and SHLW Maar Lake also shows an increasing pattern in precipitation after 150 cal yr BP [42,46].…”

Chemical stability of carbon pool in peatlands dominated by different plant types in Jilin province (China) and its potential influencing factors

“…A similar trend was also found in carbohydrate content and the effects of degradation on the carbon and aromatic contents of peatlands covered by different plant types. The most important characteristic of peatland degradation is the decreasing in the water table (Guo et al, 2013;Han et al, 2021). Due to there was no clear water table for measuring the degradation of herb/shrub peatlands and shrub peatlands, especially for dry degraded peatlands.…”

From Sphagnum to shrub: Increased acidity reduces peat bacterial diversity and keystone microbial taxa imply peatland degradation

“…However, climate warming and human activities have shifted peatland plant community composition from Sphagnum moss to vascular plants, such as Rhododendron and Chaenomeles (Laine et al, 2021). The increased coverage of shrubs in peatlands may lead to peatland degradation (Dieleman et al, 2015; Han et al, 2021). This is because the more decomposable and higher phenolic content of shrub litter increased the amount of labile carbon and dissolved organic nitrogen in peatlands and primed the decomposition of organic matter, which ultimately increased carbon loss in peatlands (Bragazza et al, 2013; Walker et al, 2016).…”