Assessment of early survival and growth of planted Scots pine (Pinus sylvestris) seedlings under extreme continental climate conditions of northern Mongolia

Abstract

Environmental factors play vital roles in successful plantation and cultivation of tree seedlings. This study focuses on problems associated with reforestation under extreme continental climatic conditions. The objectives were to assess relative seedling performance (survival and growth) with respect to plantation age, and to analyze the influence of specific climatic factors during the early stages of Scots pine (Pinus sylvestris L.) plantations. The study was carried out in reforested areas of the Tujyin Nars region of northern Mongolia on six Scots pine plantations ranging from 5 to 10 years. In each of the six plantations, five 900 m 2 permanent sample plots were established and survival rates and growth performance measured annually over 7 years. Results show high variation in survival among the plantations (p \ 0.001, F = 29.7). Seedling survival in the first year corresponded directly to the number of dry days in May. However, survival rate appeared to stabilize after the second year. The insignificant variation of height categories throughout the observation period indicated low competition among individuals. Two linear mixed-effect models show that height and radial growth were best explained by relative air humidity, which we consider to be a reliable indicator of site-specific water availability. Insufficient amounts and uneven distribution of rainfall pose a major threat during the first year of plantation establishment. Humidity and water availability are decisive factors for a successful seedling plantation. This highlights the impact of drought on forest plantations in northern Mongolia and the importance of developing climate resilient reforestation strategies.

Forest Management In Mongolia – A Review Of Challenges And Lessons Learned With Special Reference To Degradation And Deforestation

“…Based on recent research, adapted silvicultural measures for climate-resilient forest management have been proposed. These include analysis and establishment of specific selective harvesting measures and the development of adjusted regeneration and planting concepts (Gradel 2017;Gerelbaatar et al 2019b). Some European studies, for example, have reported that thinning could be a measure for climate adaptation, since it has a positive impact on the amount of water available to the remaining trees (Gebhardt et al 2014, Olivar et al 2014).…”

“…The effect of timing of reforestation success has recently been scrutinized by Gerelbaatar et al (2019b), who found that the survival rate of seedlings in Scots pine plantations is a linear function of the number of dry days (days with air humidity below 30%) during the common planting period in May. The same authors elaborated threshold values of air humidity for the dieback of planted Scots pine seedlings in the Selenge Aimag.…”

“…Survival rate and relative growth are also the main control parameters regarding reforestation for combating desertification in the frame of the above-mentioned CCDASA initiative (Khaulenbek and Kang 2017). Gerelbaatar et al (2018a;2019b) recommended the development of climate-resilient reforestation guidelines, and to test planting during autumn, depending on site conditions possible to consider also other tree species where possible. This includes also underplanting in degraded stands, which so far is not happening.…”

“…This includes also underplanting in degraded stands, which so far is not happening. The spectrum of available tree species planting methods and conditions needs to be enlarged (Gerelbaatar et al 2019b).…”

Tree-Level Above-Ground Biomass Equations for Pinus sylvestris L. in Mongolia

“…Scots pine (Pinus sylvestris L.) is one of the most widely distributed tree species in Eurasia, and has a high commercial and ecological value (Xiao & Ceulemans, 2004). For Mongolia, pine forests play an important role in domestic timber production and forest ecosystem sustainability (Sukhbaatar et al, 2019). Currently, several studies were devoted to the development of allometric equations and predicting the AGB estimation for the main tree species of a given forest region (Danilin 2004;Chuluunbaatar, 2005;Battulga et al, 2013;Danilin & Tsogt, 2015;Dulamsuren et al, 2016;Dorjsuren et al, 2018;Altanzagas et al, 2019).…”