Microenvironmental conditions for Japanese alder seedling establishment in a hummocky fen

Abstract

In this article, we focused on hummocky microtopography as a prominent feature of mires and explored the microenvironmental conditions suitable for alder seedling establishment. Japanese alder (Alnus japonica) forest is widely distributed in wetlands in northern Japan. However, because alder seedlings are rare in mires, alder population dynamics and conditions that favor the establishment of alder seedlings are still unknown. The study was conducted in northern Japan at a site in mesotrophic mire. We surveyed the seedling density, the microenvironmental conditions (light, litter cover, and soil quality), and the density of dispersed seeds in alder forest and in the adjacent herbaceous fen. In addition, we performed a laboratory experiment to examine the germination characteristics of alder. Seedlings grew only on hummocks in alder forest. The percentage of litter cover on hummocks was lower than in hollows, and the density of dispersed seeds in alder forest was much higher than in herbaceous fen. Seeds of Japanese alder germinated under both light and dark conditions, and the germination rate were high under light and high-temperature conditions. Our results suggest that litter cover may inhibit seedling establishment and hummocks that characterized by less litter cover are suitable place for the establishment of seedlings. We conclude that hummocky microtopography and abundant seed rain in the mire enable the establishment of Japanese alder seedlings.

A little relief: Ecological functions and autogenesis of wetland microtopography

“…Consequently, hummock height is positively associated with greater relative growth and biomass (Diamond et al, 2020; Roy, Bernier, Plamondon, & Ruel, 1999; Stoffella et al, 2010), foliar nutrient concentrations (Roy et al, 1999), and seedling regeneration success (Blood & Titus, 2010; Chimner & Hart, 1996; Titus, 1990). Indeed, the greater success of seedlings on hummocks (Gengarelly & Lee, 2005; Shida & Nakamura, 2011) has led to the consensus that restoration plantings on hummocks fare better than in hollows (Anderson, Landi, & Marks, 2009; Battaglia, Sharitz, & Minchin, 1999; Simmons, Wu, & Whisenant, 2011). Consequently, restoring microtopography is an emerging priority for wetland restoration projects (Bannister, Coopman, Donoso, & Bauhus, 2013; Conner, 1995; Larkin et al, 2006; Lieffers et al, 2017).…”

Effects of ecological restoration measures on the distribution of Dicranopteris dichotoma at the microscale in the red soil hilly region of China

“…Many regions are flat from a large-scale perspective. At a relatively small scale, however, the microtopography is often heterogeneous [ 12 ]. Microtopography, broadly defined as topographic variability at the scale of individual plants, describes surface variation within an elevation range from roughly several centimeters to several meters [ 13 ].…”

Allocation patterns contribute to the distributional limits of a flood tolerant ecotype of Chamaecrista fasciculata

“…Because of the relatively few species that comprise flooded communities, they are also ideal for studies of inter-specific competition as a factor in marsh zonation (Pennings and Callaway, 1992). A number of studies have documented correlations between species distributions, flooding and competitive ability (Linhard, 1973;Shida and Nakamura 2011). For example, competitive ability and flooding tolerance of three related species of Polygonum were negatively correlated when studied under greenhouse conditions suggesting that species boundaries are more influenced by competitive ability as flooding stress decreases (Carter and Grace, 1990).…”