Spatial Distribution Patterns and Ethnobotanical Knowledge of Farmland Demarcation Tree Species: A Case Study in the Niyodo River Area, Japan

Yoshinori Tokuoka,Fukuhiro Yamasaki,Kiyokazu Hashigoe,Kenichiro Kimura,Mitsunori Oka

doi:10.3390/su12010348

Abstract

Isolated trees in farmlands serve various ecological functions, but their distribution patterns and planting history are often unknown. Here, we examined the spatial distribution, uses, and folk nomenclature of farmland demarcation trees planted in the Niyodo River area in Japan. Hierarchical clustering using the data from 33 locations distinguished four tree composition groups characterized by the combination of Euonymus japonicus, Ligustrum obtusifolium, Deutzia crenata, and Celtis sinensis. Near the upper to middle reaches of the river, the group characterized by E. japonicus dominated. Near the middle to lower reaches, the group characterized by L. obtusifolium occurred relatively frequently. The other two groups were found sporadically near the upper to lower reaches. The locally unique plant name nezu, used for L. obtusifolium, seems to have originated from a word meaning “the tree does not sleep and keeps the watch” in Japanese. In the study area, D. crenata was one of the plant species utilized for the sticks (magozue) used in traditional funeral ceremonies, which might help to explain why local people maintain D. crenata around homesteads as a demarcation tree. These findings highlight both the commonalities and uniqueness of demarcation tree culture in different regions of Japan and contribute to deepening our understanding of agricultural heritage.

Highlights

The expansion of intensive agriculture and farmland abandonment threatens traditional agricultural landscapes and the intangible knowledge assets supporting such landscapes [1,2]
We investigated the spatial distribution patterns, folk nomenclature, and uses of farmland demarcation trees on the alluvial plains along the Niyodo River in the Kochi Prefecture of Shikoku Island, southwestern Japan
Farmland demarcation trees were investigated in areas along the Niyodo River in Kochi Prefecture (Figure 1)

Summary

Introduction

The expansion of intensive agriculture and farmland abandonment threatens traditional agricultural landscapes and the intangible knowledge assets supporting such landscapes [1,2]. Isolated trees in farmland serve multiple functions. They support faunal biodiversity [3] and local food security [4], provide various collective goods [5], and maintain farmland demarcation. How the locally specific composition of isolated trees was historically shaped remains unknown in most regions, because of the lack of historical information. Under such limitations, ethnobiological approaches that analyze the ecological, botanical, and linguistic perceptions of local people can provide clues to the history of isolated trees in farmland landscapes

Methods

Results

Discussion

Conclusion