Secondary Succession and Natural Habitat Restoration in Abandoned Rice Fields of Central Korea

Abstract

Floristic composition and soil characteristics (moisture, pH, nutrient contents) in abandoned upland rice paddies of different ages were analyzed to clarify the regenerative aspects of succession as a tool for habitat restoration. The study sites represented five seral stages: newly abandoned paddy fields; successional paddy fields abandoned for 3, 7, and 10 years; and a 50‐year‐old Alnus japonica forest. A vegetation sere was apparent in changes of dominant plant species in the order Alopecurus aequalis var. amurensis (annual grass), Aneilema keisak (annual forb), Juncus effusus var. decipiens (rush), Salix koriyanagi (willow), and Alnus japonica (alder) communities. These temporal stages resemble the spatial zonation of vegetation in local riparian floodplain ecosystems, indicating a hydrosere, with soil moisture decreasing over time. Age distributions and life forms of the dominant plant species support a “tolerance” model of secondary succession, in which the established species persist into later successional stages. Persistence of earlier colonizers led to a net cumulative increase in species richness and a more even distribution of species cover with increasing field age. Between 10 and 50 years, vegetation stabilizes as an alder community. Soil moisture content decreased steadily with paddy field age after an initial rise immediately after their abandonment, whereas pools of organic matter, N, P, K, Ca, and Mg, increased with field age. The pace and direction of recovery of native vegetation and natural soil properties in these abandoned rice paddies resembled classic old field succession, a form of secondary succession that often serves as a template for guiding restoration efforts. Active intervention, in particular dismantling artificial levees, could accelerate the recovery process, but natural habitat recovery generally appears sufficiently robust to achieve “passive” restoration of this rare community without intervention.

Optimal environmental range for Juncus effusus, an important plant species in an endangered insect species (Nannopya pygmaea) habitat in Korea

“…of 79%, which corresponded to the result that J. effusus was well represented in a 3-year-old abandoned field and continued to increase to maximum in a 7-year-old field during the early stage of succession when water had been drained out, i.e., abandoned paddy fields (Lee et al 2002). In the ORD of WD, the median density, coverage, I.V., height and species diversity of J. effusus was 186 individuals/m 2 , 52.5%, 116.9%, 92.5 cm, and 0.4, respectively.…”

“…Abandoned paddy fields at the early successional stage serve as habitat for Nannopya pygmaea, an endangered dragonfly species in Korea (Yoon et al 2010). Juncus effusus (soft rush or common rush) is the predominant species in fallow rice fields abandoned for 3-10 years (Lee et al 2002) and plays an important role in N. pygmaea habitats (Yoon et al 2010). Therefore, it is necessary to understand the environmental characteristics of J. effusus to restore, create, or manage N. pygmaea habitats.…”

“…Juncus effusus has been well studied with respect to its autecology (Richards and Clapham 1941a, 1941b, Lazenby 1955a, 1955b, Grime et al 1990, Ervin and Wetzel 1997, Wetzel and Howe 1999, potential interactions with other wetland plant species Wetzel 2000, 2001), and the distribution of plants occurring during succession (Comin et al 2001, Lee et al 2002, Koo 2003. Numerous studies have indicated that J. effusus is a prominent component of soil seed banks (Chippindale and Milton 1934, Champness and Morris 1948, Thompson and Grime 1979, Grime et al 1990).…”

Vegetation and soil properties in restored wetlands near Lake Taihu, China

“…Results showed that soil quality improved with time due to accumulation of TOC, TN, TP, and improvement of soil texture. Similar results were reported in terrestrial ecosystems (Browman et al, 1990;Peng, 1995;Kosmas et al, 2000;Comin et al, 2001;Singh et al, 2001;Lee et al, 2002;Bruland & Richardson, 2004, 2005. Soil pH in riparian areas ranged from 4.90 to 5.28 in the 0-20 cm layer and 5.68 to 5.92 in the 20-40 cm layer in Fig.…”

Spatial Autocorrelation Analysis among Subpopulations of Salix koriyanagi in Swampy Area at the Namgang River, Korea

“…Salix koriyanagi Kimura ex Goerz is a deciduous shrub and native to Korea, but is widely grown by the Japanese for use in basketry [13]. S. koriyanagi is a large, upright, multibranched shrub, which can reach a height of 2-3 m at maturity.…”