An endangered orchid, Cephalanthera longifolia, recently expands their habitat to developed lands, such as parks and landfills. This shows that developed lands can be available for the habitat of the endangered orchids, that is an interesting model for considering the ecosystem in urban area. However, the factors that allow this orchid to colonize in developed lands still remain unclear. This orchid, which is so-called “partially mycoheterotrophic plants”, depends on the symbiotic mycorrhizal fungi for their nutrient supply, especially in germination stage. To clarify which fungal groups induce its seed germination and are involved in its colonization in developed lands, we conducted in situ seed germination method in the landfill site and identified the symbiotic fungi of the seedlings. Three Thelephoraceae fungi were mainly involved in the seed germination of C. longifolia. These fungi were found from various growth stages of the seedlings and distributed across the study site regardless the soil depth and the inoculation point, suggesting that they play a key role in the seed germination and development of the seedlings. Thelephoraceae fungi have ectomycorrhizal association with the Pinaceae and Fagaceae trees. Stable symbiotic relationships were developed between these planted trees and Thelephoraceae fungi, and these relationships allowed this orchid to colonize in the developed land.

Extensive green roofs have benefits of weight and cost reduction for the buildings, though their shallower substrates resulted in fewer options of plant species to introduce and lower water holding capacity. Although previous studies reported that companion planting with Sedums and biochar amendment can improve soil water content, their synergistic effects were not fully clarified. Therefore, this study aimed to reveal the effects of the combination of companion planting with Sedums and biochar amendment on the health conditions of the plants. We cultivated two plant species for green roofs (Mimosa pudica and Rosmarinus officinalis) with/without Sedum album in a greenhouse under drought condition for 16 days. Additionally, we added biochar at rates of 0, 15, 30 and 60％ by volume to the substrates. The results indicated that there were no significant synergistic effects by the combination between soil water content and water holding capacity. However, the health conditions of plants were healthy when biochar was added and/or Sedums were planted together. Additionally, water holding capacity was improved with the increase of biochar application rate. In conclusion, we revealed that although synergistic effects between companion planting with Sedums and biochar amendment would not be induced on green roofs, the effects of biochar amendment can improve water holding capacity without wilting of the plants.

The damage caused by sika deer (Cervus nippon) on road slopes and in artificial forests has become an issue in recent years, resulting in tests being conducted that focus on plants that are unpalatable for the deer. Downy ground fern (Hypolepis punctata) is one such unpalatable plant that has proven effective for greening. However, while spore sowing of downy ground fern has been reported as a suitable propagation technique for greening, the sporophyte growth was slow and only a small number of seedlings were obtained. Therefore, in this study, we investigated whether the propagation method that is used for eastern bracken (Pteridium aquilinum) can be applied to downy ground fern, wherein rhizome buds are planted to produce more seedlings in a shorter time. Furthermore, we investigated whether the buds could be efficiently multiplied by growing potted seedlings to avoid the need to excavate rhizomes from forest lands. We found that this propagation method resulted in a germination rate and a seedling yield of ＞60％, and a total of 325 seedlings were obtained indicating that it is a suitable method for seedling production. We also found that planting was possible two months after budding and propagation was possible in the following spring, which significantly reduced the breeding period. Moreover, by growing the resulting seedlings, it was possible to obtain 20―30 times the number of buds that were initially used. Thus, this method greatly reduced the required labor and enabled efficient seedling production.