The distribution of fine root length density for six artificial afforestation tree species in Loess Plateau of Northwest China

Abstract

Aim of the study: Data about the distribution of fine root length density (FRLD) is important to understand the ecophysiology of vegetation. This is particularly true when models are applied to describe ecohydrology and vegetation function. However, there is yet limited knowledge of root distributions in semi－arid regions. The aim of this study is to investigate the distribution of fine roots for six typical afforestation tree species in Loess Plateau and its relationships with soil environmental factors.Area of study: Loess Plateau (NW of China).Material and methods: We quantified the fine root length density distribution of six typical afforestation tree species by soil core method, and the soil properties also were investigated.Main results: More than 50% of fine root length was concentrated at depths between 0 and 40 cm in vertical direction. In horizontal direction, most of fine roots concentrated near the trunk. Results showed a significant negative correlation between vertical distribution of FRLD and soil water content, a positive correlation between FRLD and organic matter and total N is significant, and a negative correlation with bulk density. No relationships were found with total C and particle size distribution in any soil layer for the six tree species. Stepwise multiple linear regression confirmed that changes in different soil properties significantly affected the variation in FRLD for each tree species, total N had strong and positive relationships with FRLD.Research highlights: These measurements provide valuable data for modelling of ecosystem water use and productivity.Keywords: Anjiapo catchment; Core method; Root distribution; Soil moisture; Soil properties.

Water use characteristics of the common tree species in different plantation types in the Loess Plateau of China

“…pseudoacacia (Jian et al, 2015). For this reason, A. sibirica in Mspa derived a higher proportion of shallow soil water (60.96%) than R. pseudoacacia in Mspa (43.72%) during the growing seasons.…”

“…These findings imply that A. sibirica and R. pseudoacacia in the different plantation types exhibited distinct water use characteristics. This discrepancy may be attributed to their different ecophysiological characteristics, such as different lateral root distributions (Jian et al, 2015), specific leaf areas (Yan et al, 2010), plasticity of minimum leaf water potential (Miyazawa et al, 2018), and osmotic adjustment ability (Yan et al, 2013). In the same catchment, Wei et al (2018) reported that R. pseudoacacia was negatively affected by water stress but A. sibirica was not by comparing inter-annual radial growth responses to climate change using tree-ring samples in the same catchment.…”

Estimation of water use of Pinus tabulaeformis Carr. in Loess Plateau of Northwest China

“…The LAI of the trees in the three plots was 2.65±0.31 (mean±SD), tree height was 10.15±3.64 m (mean±SD), and diameter at breast height (DBH) was 20.3±3.7 cm (mean ±SD). The root distribution of P. tabulaeformis was shallow (Jian et al, 2015), more than 90% of the roots was concentrated in the 0-100 cm soil depth.…”

Deep soil ploughing for afforestation: a review of potential impacts on soil and vegetation

“…Although fine tree roots account for less than 2% of tree biomass, they can contribute to 75% of primary production in mature forests annually, making them important for forest carbon, nutrient, and water cycling processes (Gill andJackson 2000, Brunner and. Fine roots are concentrated on the soil surface and decrease steadily with increasing soil depth (Macinnis-Ng et al 2010, Jian et al 2015. Studies performed in the plantations of six tree species established on agricultural land have shown that the highest fine root density was concentrated at a depth of 0-40 cm (Jian et al 2015).…”

“…Fine roots are concentrated on the soil surface and decrease steadily with increasing soil depth (Macinnis-Ng et al 2010, Jian et al 2015. Studies performed in the plantations of six tree species established on agricultural land have shown that the highest fine root density was concentrated at a depth of 0-40 cm (Jian et al 2015). Otherwise, fine roots are known to develop very plastically in response to changing environmental conditions (Meier and Leuschner 2008).…”