Seed Burial Depth and Soil Water Content Affect Seedling Emergence and Growth of Ulmus pumila var. sabulosa in the Horqin Sandy Land

Jiao Tang,Ala Musa,Dafu Wu,Carlos Busso,Yongcui Wang,Deming Jiang,Chunping Miao,Renhui Miao

doi:10.3390/su8010068

Abstract

We investigated the effects of seed burial depth and soil water content on seedling emergence and growth of Ulmus pumila var. sabulosa (sandy elm), an important native tree species distributed over the European-Asian steppe. Experimental sand burial depths in the soil were 0.5, 1.0, 1.5, 2.0 and 2.5 cm, and soil water contents were 4%, 8%, 12% and 16% of field capacity. All two-way ANOVA (five sand burial depths and four soil water contents) results showed that seed burial depths, soil water content and their interactions significantly affected all the studied plant variables. Most of the times, seedling emergence conditions were greater at the lower sand burial depths (less than 1.0 cm) than at the higher (more than 1.0 cm) seed burial depths, and at the lower water content (less than 12%) than at the higher soil water content. However, high seed burial depths (more than 1.5 cm) or low soil water content (less than 12%) reduced seedling growth or change in the root/shoot biomass ratios. In conclusion, the most suitable range of sand burial was from 0.5 to 1.0 cm soil depth and soil water content was about 12%, respectively, for the processes of seedling emergence and growth. These findings indicate that seeds of the sandy elm should be kept at rather shallow soil depths, and water should be added up to 12% of soil capacity when conducting elm planting and management. Our findings could help to create a more appropriate sandy elm cultivation and understand sparse elm woodland recruitment failures in arid and semi-arid regions.

Highlights

Seed production and dispersal, the dynamics of soil seed bank, and seed germination and establishment are important processes contributing to the regeneration of natural vegetation [1]
Two-way analysis of variances (ANOVAs) analyses showed that depths of sand burial, soil water content and their interactions had a significant effect on the final percentage of emerged seedlings and the rate of seedling emergence (p < 0.001, Table 1)
Seedling emergence percentage was more than 12.9% greater (p < 0.05) at 0.5 than at 1.0 cm of seed burial depths in each of the soil water contents (Figure 1A)

Summary

Introduction

The dynamics of soil seed bank, and seed germination and establishment are important processes contributing to the regeneration of natural vegetation [1]. Seed germination and seedling establishment are the most sensitive processes (e.g., water stress [2]) among these plant life history traits [3]. Su et al [4] reported that water stress is a major obstacle for a successful vegetation establishment in arid and semi-arid regions. Other abiotic stresses such as temperature, light and low nutrient contents are dominant aspects altering the fate of seeds [5,6]. Decisive factors impacting vegetation restoration in arid regions are successful seed germination and the subsequent establishment and development of seedlings [9,10]

Objectives

Methods

Results

Conclusion