Biodiversity Conservation Ecological Network Concept
Biodiversity Conservation Activities at Panasonic Kusatsu Factory
Panasonic Corporation's Kusatsu Factory is in the Seta Hills, which has had a unique natural environment since ancient times and is surrounded by SATOYAMA forests of quercus oak and red pine, as well as many agricultural ponds. In addition, it is located almost halfway between Lake Biwa and the Tanakami Mountains, which have a valuable natural environment.
In October 2011, we announced the "Ecological Network Concept in Eco Idea Factory Lake Biwa," which aims to contribute to local biodiversity through the development and conservation of plant green spaces, and we are promoting biodiversity conservation activities centered on the Forest of Coexistence.
Ecological Network Concept connecting the Forest of Coexistence and the surrounding environment.
An ecological network aims to secure habitats for living things by connecting habitats and breeding grounds of living creatures, such as forests, grasslands, and waterfronts, with corridors such as green spaces.
Specifically, we conduct flora and fauna surveys of the Kusatsu Factory and the surrounding area to understand what kind of creatures live there and how they use the Kusatsu Factory, and then conserve green spaces with favorable habitat conditions as the "Forest of Coexistence" and work to connect the green spaces around the plant using green spaces and tree-lined areas on the factory site as corridors.
Certified as a "Nationally Certified Sustainably Managed Natural Sites"by Ministry of Environment
In March 2022, we joined the Japanese Ministry of the Environment's 30by30 Alliance to contribute to the "30by30" initiative, which is being promoted by the world to conserve 30% of each country's land and sea area by 2030. In October 2023, it was certified as a " Nationally Certified Sustainably Managed Natural Sites".
It is designated by the national government as areas that have biodiversity value and are being conserved through various initiatives by businesses, private organizations, individuals, and local governments. In line with this, the forest of Coexistence will be registered in the OECM International Database*.
*In order to achieve the 30 by 30 goal, we will not only expand national parks, etc., but also create SATOCHI, SATOYAMA, corporate forests, shrine, and temple forests, etc.
We will register land that is being conserved for biodiversity by regions, companies, and organizations in an international database as OECM (Other Effective Area-based Conservation Measures) and promote its conservation. (From the website of Ministry of the Environment of Japan)
Concepts of national and local governments
It is desirable to build networks at various levels, from the international scale that transcends national borders such as geese, ducks, and whales, to the regional scale such as raptors and foxes.
Association for Business Innovation in harmony with Nature and Community of Japan
Panasonic's "Forest of Coexistence" of the Eco Ideas Factory Lake-Biwa, i.e. Kusatsu Factory has been certified as the 5th "Business Facility ® for Symbiosis with Nature" operated by the Council for the Promotion of Business in Harmony with Nature and Nature.
About the Shiga Prefectural Biodiversity Initiative Certification System
In Shiga Prefecture, where the Kusatsu Factory is located, the Shiga Biodiversity Initiative Certification System was launched in fiscal 2018.
This system was implemented to support business activities that protect living things and make sustainable use of natural resources, and according to the number of initiatives, it is certified by the Governor of Shiga Prefecture with 1 star ~ 3 stars, and the certification mark can be widely used for economic activities.
In recognition of the various initiatives of the Kusatsu District Office for the "Ecological Network Concept Connecting the Coexisting Forest and the Surrounding Environment," we received the 2018 certification mark (3 stars) as a 2018 certifier of the Shiga Biodiversity Initiative Certification System.
About the Forest of Coexistence of Kusatsu Factory
The "Forest of Coexistence" is positioned as an important green space in Panasonic's "Ecological Network Concept," which aims to "Contribute to local biodiversity" and "Preserve the landscape," and is a green space that is engaged in conservation activities that take into consideration the habitats of living creatures.
In conservation activities, we use the SATOYAMA model of the surrounding area, which has multiple types of environments, such as forests, grasslands, and waterfronts, and promote the cultivation and planting of serrata (acorn) saplings by employee volunteers.
Furthermore, in addition to quantitatively assessing the quality of green spaces through monitoring by experts, we manage green spaces using indicator organisms by employees, monitor specific alien species, and carry out conservation activities using local seedlings.
Environmental Conservation Activities at the Kusatsu Factory
Conservation goal: Conservation of biodiversity, including in the surrounding area.
As a firewood charcoal forest, the Seta Hills have developed forests where mainly red pine and quercus oak grown, and large and small ponds made for irrigation are arranged along the hills, and there are multiple types of environments that connect from the waterfront to the forest. It is inhabited by goshawks and foxes, which are positioned as high-order consumers in the local ecosystem, as well as amphibians and dragonflies such as the Kasumi salamander, which uses both the waterside and the forest during its lifetime. It is the core of biodiversity conservation in areas where urbanization is progressing.
In carrying out conservation activities, in addition to surveying the flora and fauna of the entire plant, we also survey the SATOYAMA in the surrounding area, and in the Kusatsu factory, we position the green spaces that have the potential to contribute the most to the habitat of living things as important green areas, and we are conducting conservation activities using the SATOYAMA of the surrounding area, which has multiple environmental types such as forests, grasslands, and waterfronts, as a model of the "Forest of Coexistence".
Conservation activities with employee participation
In order to conserve the Forest of Coexistence, we promoted "forest foster care activities" in which acorns (hard fruits) are collected from quercus oak trees that grow wild on the factory grounds, grown into saplings at employees' homes, and planted in the forest regeneration area of the Forest of Coexistence, based on the regeneration of SATOYAMA with trees that correspond to the vegetation of the region.
Maintenance and Management Activities
Implementation of monitoring
In order to quantitatively grasp the status of the regeneration of the SATOYAMA environment in the Forest of Coexistence, we continue to monitor plants, insects, and aquatic organisms by experts and reflect them in the conservation plan.
JBIB (*) Guidelines for Workplaces in Harmony with Nature and Nature (Use of Land Use Report Cards)
In the maintenance and management of the green space in the plant, we will utilize the JBIB Guidelines for Workplaces in Harmony with Nature and Nature, and will continue to evaluate them using the Land Use Report Card.
(*) JBIB : Japan Business Initiative for Biodiversity
Response to specified alien species, etc.
Currently, some of the alien species that have been confirmed in the "Forest of Coexistence" include bullfrogs, American crayfish, and other species that have a significant impact on the native ecosystem of the region, and these creatures are captured as appropriate in the maintenance and management process. In addition, we are considering the degree of impact on plants and taking the same measures.
Since the presence of raccoons (specified alien species) has been confirmed in the surrounding SATOYAMA, we are monitoring these invasions and taking appropriate measures such as reporting them to local government agencies if they are found.
Monitoring Report (2011~2016)
This is a compilation of data obtained up to 2016 on the assessment of the impact on local ecosystems based on forest maintenance and management based on monitoring surveys started in 2011 and living organisms.
Biodiversity in the Forest of Coexistence
- Flora and fauna living in the Forest of Coexistence: 840 species (29%)
- Total factory site: 955 species (33%)
* Figures in parentheses are percentages of the number of species confirmed in "Nature in Kusatsu City 2014"
As of 2016, 840 species of plants and animals had been identified in the Forest of Coexistence, which is equivalent to about 30% of the number of species confirmed in Kusatsu City. Considering that the area of Kusatsu City is about 6,800 hectares and the Forest of Coexistence is about 2.6 hectares, it can be said that the number of species per area of the Forest of Coexistence is extremely large.
As for the characteristics of each taxon, about 70% of the species of mammals confirmed in Kusatsu City have been confirmed, confirming that the Forest of Coexistence is an important biotope in Kusatsu City, where residential development is progressing.
Notable species of the Forest of Coexistence
Species displaying RDB are those listed in the Red Data Books of Shiga Prefecture, and the Ministry of the Environment of Japan.
Harvest mouse (mammal)
A small rat that uses grassland. Nesting annually in pampas grass, cogon grass, sedges, etc.
Eurasian sparrowhawk (bird)
A bird of prey that stands at the top of the ecosystem of the Forest of Coexistence. Used as a feeding ground during the wintering season.
Striated heron (birds)
The waterside is used as a feeding ground. Its nesting was also confirmed in the factory green space.
Japanese grass lizard (reptile)
Soak up the sun on the installed wooden deck. It feeds on grassland insects.
Dragonfly *Sympetrum baccha matutinum (insect)
Our forest is used by it as a place for adult insects to grow. The number of individuals is small in Shiga Prefecture.
Monarch stink bug *Eucorysses grandis(insect)
Observed from autumn to winter. The detailed ecology is unknown.
Chestnut Tiger (insect)
Butterfly flying and traveling long distances. Sometimes they cross the ocean. (migratory butterfly)
Grasshopper *Gonista bicolor (insect)
Prefers tall grasslands of cogon grass. Its habitat in Shiga Prefecture is limited.
Promethis valgipes (insect)
Eat decaying wood and turn it back into soil. The detritivores in the forest.
Ammannia multiflora Roxb. (plant)
Annual undersized paddy weed. A remnant of the former paddy fields. Appeared after the development of the biotope.
Juncus krameri (plant)
Perennial wetland plant. Confirmed in temporary waters. In Shiga Prefecture, distribution records are scarce.
Scirpus fuirenoides Maxim. (plant)
A plant that represents the wetlands of the eastern and southern regions surrounding Lake Biwa. Appeared after the development of the biotope.
Amur corktree (plant)
Seeds of the trees may be carried by birds and settled. However, there is no natural habitat in the vicinity. It is a swallowtail larval food plant, and larvae have already been confirmed.
Japanese bay tree (plant)
Trees that make up the natural forests of the area. Seeds are dispersed by fruit-eating birds.
The food chain of the Forest of Coexistence
The most important feature of biodiversity in the Forest of Coexistence is that different ecosystems such as grasslands, waterside, and forests coexist, and many species coexist through various interspecies relationships.
Forests: Plants that are producers, such as Japanese hackberry, Japanese bay tree, and oak, are food resources for consumers such as butterflies and insects, and there is a symbiotic relationship with red mice, bulbuls, and Japanese pygmy woodpeckers not only as food resources but also in terms of transporting seeds.
Waterfront: Mosquitoes that feed on tree litter serve as food resources for dragonflies, and planted sedges play an important role as spawning and hiding places for dragonflies.
Grasslands: Producers such as cogon grass and boneset are the starting point, and the former is a habitat for many grassland insects, and the latter has a symbiotic relationship with flower-visiting insects that carry pollen in exchange for sucking nectar. And shrike that prey on these grassland insects can be seen on an annual basis.
The top consumers such as foxes, Japanese rat snakes, falcons, and hawks, which use each ecosystem in a cross-sectional manner, are positioned as the pinnacle of the ecosystem of the Forest of Coexistence. In addition, decomposers such as Eusilpha japonica, earthworms, and wood ear play a role in decomposing animals that are consumers and plants that are producers and returning them to the soil.
Enhancement of biodiversity through adaptive management
Conservation of native species and control of invasive species
In 2011, we developed the Forest of Coexistence and biotope area and started adaptive management. Since 2013, we have been able to maintain the native flora of the region by suppressing the overgrowth of non-native species and encouraging the establishment of native species in response to the increase in the number of non-native species.
Changes in the number of native and non-native plant species in the Forest of Coexistence
Table of changes in the number of native plants and non-native plant species
|
Year |
2011 |
2012 |
2013 |
2014 |
2015 |
|---|---|---|---|---|---|
|
Native species |
159 |
214 |
257 |
233 |
233 |
|
Non-native species |
51 |
57 |
68 |
63 |
49 |
Species to be weeded (Invasive alien species)
Grassland
Poa trivialis, Tall fescue, Carolina geranium, Tall golden rod, Catsear, Fleabane, Horseweed, Bluestem, Hairy beggarticks, Rat's-tail fescue, African lovegrass, Pokeweed, Hybrid ryegrass, Daisy fleabane
Forest
Tree privet, Berberis japonica
Waterside
Pterocarya stenoptera, Devil's beggartick, Bluestem
Species to be conserved
Grassland
- (Locality): Cogon grass, Ixeris japonica, Boneset, Japanese dandelion *Taraxacum japonicum
- (Rarity): Carex maculata, St. Johnswort
- (Food resources): Metaplexis japonica, Lespedeza juncea (L.fil.) Pers. var. subsessilis Miq., creeping woodsorrel
Forest
- (Locality): Japanese hackberry, Aphananthe aspera, Jolcham oak, Frangula crenata
- (Rarity): Japanese Bird Cherry, Amur corktree, Ficus erecta var. erecta, Ternate grapefern
- (Food resources): Japanese pepper, Ailanthus-like prickly ash, Japanese bay tree
Waterside
- (Locality): Swamp millet, Fuiren Bulrush, Carex dimorpholepis, Scirpus wichurae
- (Rarity): Rotala indica var. uliginosa, Epilobium pyrricholophum, Persicaria sagittata var. sibirica
- (Food resources): Water dropwort
Diversity of dragonflies by maintaining the waterside environment
In the Forest of Coexistence, new waterways have been established, and many aquatic plants such as sedge have been planted on the revetments, forming an ecotone between the water and the land. As a result, water bodies with different environments, including existing reed communities, concrete waterways, and detention ponds, have been created.
Dragonflies use waterside as a breeding place, but each species has a different preference for waterside environments.
The Forest of Coexistence is home to a wide variety of water bodies with different vegetation, current velocities, and scales, so many species of dragonflies live in response to each environment.
Waterside biotope
Dragonflies confirmed in water biotope
Indolestes peregrinus, Asiagomphus pryeri, Common Spreadwing Emerald damselfly, Jumbo dragonfly, Ceriagrion melanurum, Scarlet skimmer, Wide-bellied Skimmer, Martin dragonfly, Summer darter, Sympetrum eroticum
Reservoirs
Dragonflies found in the reservoir
Lestes temporalis, Sieboldius albardae, Golden flangetail dragonfly, Pied skimmer
Dragonflies found in both the biotope and the reservoir
Asian blue tail, Marsh bluetail, White-tailed skimmer, Dusky lilly-squatter, Greater blue skimmer, Copera annulata, Globe skimmer, Calopteryx atrata, Butterfly dragonfly, Blue-spotted Emperor, Lesser emperor, Autumn darter
Promote germination and survival in deciduous forests
In the Forest of Coexistence, the planting and development of shrubs has led to the use of many bird species in this forest, and the growth of the forest floor has been suppressed by mowing and selective weeding, and various seedlings have been observed. Therefore, we investigated how seedling germination and residual density change by suppressing the undergrowth of about 1 meter high that grows under the forest.
As a result, it was confirmed that the germination and survival of seedlings is promoted by suppressing vegetation on the forest floor through maintenance and management in deciduous forests.
Improving the diversity of grassland insects by uncut
In the Forest of Coexistence, various types of grasslands are maintained by adaptive management, such as perennial cogon grass communities, boneset communities and annual southern crabgrass communities, and green bristlegrass. These grasslands are expected to undergo significant changes in structure and composition when regular mowing and selective weeding are stopped.
Therefore, on a trial basis, a part of the normal mowing range was left unmowed and changes in the grassland structure were surveyed.
As a result, mowing is necessary to maintain the grassland environment, but by providing a partially unmowed area, the number of insect species and populations can increase, and the diversity of living things in the grassland as a whole can be improved.
The Forest of Coexistence and Ecological Networks
Coexistence of birds and plants
According to the results of our 2015 survey of the flora of the Forest of Coexistence by seed dispersal form, it was revealed that out of 282 plant species, animal dispersal was high at 106 species, which is 40% of the total. Furthermore, according to the breakdown of animal dispersal species, endozoochory is the most common, accounting for 70% of the total (76 species).
There are mammals such as raccoon dogs that eat fruits in the Forest of Coexistence, but most of them are birds. Therefore, it is thought that the flora of the current Forest of Coexistence is greatly influenced by seed dispersal by fruit-eating birds.
Germination of seeds and seedlings dispersed by birds
A total of 41 species of bird-dispersing plants were collected by seed traps installed in the Forest of Coexistence, and many seeds were collected in the order of Yama-haze(Toxicodendron sylvestre), East Asian mallotus, Ubame oak, and Japanese angelica tree.
Ilex Macropoda and Elaeagnus multiflora var. hortensis were identified as species that have not been confirmed in the flora survey of the Forest of Coexistence, and Glossy Privet were identified as species for which fruiting individuals have not been confirmed. These species are thought to have been brought to the Forest of Coexistence from outside by fruit-eating birds.
Ecological network with seed dispersal by birds
Centered on the Forest of Coexistence, seedlings from the Forest of Coexistence will be planted in spaces where there are lesss creatures nearby (street trees, residential areas, other factory green spaces, green space parks, etc.).
As the seedlings grow, fruit-eating birds will fly in from the Forest of Coexistence, and the number of plant species will naturally increase by dispersing a variety of seeds there. As the trees grow, fruit-eating birds come and go from biotopes other than the Forest of Coexistence, and further biotopes are formed as seeds are dispersed with each other.
Thus, seed dispersal by birds has the potential to form and strengthen the ecological network of urban areas with few green spaces.
Other species that index the network
Taxon: Dragonflies
Indexicality: Adults have a high ability to move, and larvae use water bodies as a place to grow. Indicator organisms of the water body ecological network
Taxon: Butterflies
Indexicality: Adults have a high ability to move, and the nectar source of adults and the food of larvae vary depending on the species. Indicator organisms of the green space ecological network.
Taxon: Mammals
Indexicality: Due to the large number of nocturnal species, they are rarely seen, but they make clever use of the green spaces of the city. They are the indicator creatures of a wider range of green spaces ecological networks.
Assessment of the current state of the Forest of Coexistence
A variety of vegetation, mainly native species, is maintained through the maintenance and management of the Forest of Coexistence.
As a result, the diversity of terrestrial insects and birds is high, and butterflies, dragonflies, and birds move back and forth between the Forest of Coexistence and the surrounding green space, and the seed dispersal of plants by birds was confirmed, confirming the existence of an ecological network connecting the Forest of Coexistence and the surrounding green space.
We will continue to control alien species through adaptive management and promote initiatives to improve biodiversity.
Terminology
Biodiversity:
The individuality and connection of living things in a certain area. It is described at three levels (ecosystem diversity, species diversity, and genetic diversity).
Adaptive Management:
This is a method of constantly monitoring and managing ecosystems with high uncertainty and non-stationarity, and reviewing management plans by feeding back new knowledge.
Ecological Network:
The aim is to connect the habitats and breeding grounds of living creatures to each other with corridors such as green spaces, and to secure habitat for living creatures.
Regional Species:
Plants are collected from trees that grow wild in the area, and have a reliable history such as the place of collection and the date of collection.