ICSZ-ICA Joint Symposium

Soil biodiversity for our future earth

August 26, 2016 13:00-16:30

The hyper-diverse soil: our source of food.

Sina Adl (Professor, University of Saskatchewan)

The soil is the most diverse place on earth, with more species than anywhere else. Why is there so much diversity of species, and what do they do in the soil? A look at the biological interactions helps to understand the role of species in decomposition. We have some understanding of how decaying substances become soil, and transformed into nutrients for roots. There are basic rules that govern the process, and it is called soil ecology. Modern techniques allow us to see into soil without disturbing it. These recent advancements are changing how we do soil ecology, and allow us to finally address big questions about diversity and soil function. This topic is important today because we have to feed more and more people, while climate is changing.

Sina Adl_LowRes

Colorful fungus–Collembola interactions in brown ecosystems

Taizo Nakamori (Associate Professor, Yokohama National University)

A diverse range of creatures live in the soil and interact with each other. How do their different characteristics affect the ways in which they interact? Here, we present the example of mushrooms and mushroom-feeding springtails. The mushroom Strobilurus ohshimae has insecticidal cells that are capable of killing springtails upon contact, and it is rarely eaten by springtails. However, certain springtail species that have unique feeding modes preferentially consume the mushroom. In this case, the mode of feeding determines whether or not the springtail species can eat the mushroom. As another example, springtail species that have molar plates damage fungal spores through feeding, but those lacking molar plates can carry the spores undamaged. The latter types of springtail species may interact with mushrooms not only as consumers but also as agents of spore dispersal. In these ways, species-specific characteristics determine the things with which species interact, and how they interact. If we examine soils carefully we find that they are filled with a diverse range of biotic-interactions.

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Agroecology and “tada-no-mushi” ーDetrital infusion support paddy rice above and under-ground food web

Kazumasa Hitaka (Associate Professor, Ehime University)

It had been well known an meaningful expression“tada-no-nushi”in Japanese since 1980’s, which is a concept for explaining ecological or agronomical position of arthropods in agroecosystems, although its already used having their roots in our livelihoods. This Japanese expression had been happened to meet in three academic and practical scene. When, firstly, come across it during discussion in laboratory of insect pest management, this expression used for explanation of EIL (Economic Injury Lebel) in IPM (Integrated pest management). Kiritani (1984) interpreted “tada-no-mushi” that insect pest populations could change from harmful density to neutral lower density, if they were less abundant than injury level for agricultural production. “Tada-no-mushi could be identified as neutral arthropods in agroecosystems. Secondly conducting a comparative examinations of biological community in irrigated rice fields under natural or organic farming and intensive conventional farming ones, their species diversity and abundance of collembolan species and Mermithidae, in particular, under natural, organic tenure fields had been noticed in the exception of pest species and its beneficial natural enemies (Hidaka 1990; 1993). In this cases of fields scene,“Tada-no-mushi” could be regard as ordinal arthropods in community level of agroecosystems. My third meeting “tada-no-mushi”, happened in experimentally test tube which artificially rearing Akaboshia matsudoensis (KINISHITA 1916). They could feed in the pasture of some fungus disease of agroecosystems and were preyed upon polyphagous natural enemies of pests such as spiders and Microvelia spp. (Takahashi & Hidaka 1992; Hidaka 1994; Hidaka 2012) in fields. “Tada-no-mushi”finally become functionally meaningful arthropods from the viewpoint of agroecology, because a word“tada”expresses what is not ordinary.
Really, how many species of “tada-no-mushi” are there in agroecosystems of our planet ? It has been clear that large number of species live under and above soil in agroecosystems, but richness of “tada-no-mushi”could not be seen anywhere under the present agroecosystems. How can we create and sustain agroecosystems which they can play a functional role for ecosystem services. “Tada-no-mushi”might be not neutral, ordinal or unknown but meaningful arthropods in the nature.

hidaka
Tea break

Mainstreaming soil ecosystem services, a way towards sustainable biomass production

Katarina Hedlund (Professor, Lund University)

Soils and their biodiversity form the basis of agricultural production systems and generate a range of fundamental ecosystem services, such as providing food, feed, and fibre. Soils also provide a number of services that regulate climate factors, as retaining carbon and nutrients in soils. Yet soil degradation is widespread due to intensified management and cause erosion, loss of soil organic matter and compaction that are threatening soil fertility. With a higher demand of biomass production on agricultural land the intensification of agriculture is projected to further increase. To meet the increasing pressures on agricultural land we have in several research project quantified the negative impacts of intensive arable cropping systems on soil ecosystem services and have also analysed how soils can be better managed to mitigate climate change and reduce nutrient input and ultimately, improve the long-term incomes of farmers. This has been linked to mainstream ecosystem services to farmers’ economic decision making by combining production, land use, soil biodiversity and sustainability in socio-economic models that can be used to analyse the consequences of current and planned policies at global level.

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Made in Japan; “Natural Farming” (no-tillage with weed management) can serve the highest ecosystem functioning for agriculture

Nobuhiro Kaneko (Professor, Yokohama National University)

It is often discussed that the attitudes to the nature are various among different cultures. Sometimes people try to concur the nature to establish their civilization, and it seemed to be successful to lead the modern industrial society. However, we now realized that the natural capital, especially soil will put ceiling food production thus human population. Controlling crop production by adding fertilizers and agro-chemical proved to damage soil ecosystem, and it lead serious soil degradation. Because once degraded soil is difficult to rehabilitate, therefore, we need to encourage soil protection and improvement based on ecological ideas. There are substantial number of small scale Japanese farmers who are practicing so called “natural farming”. The basic ides is to avoid elimination of weeds, instead they prefer to grow crops with weeds. I presume that the reason of popularity of this management is based on the idea that human is part of the nature and living with weeds, which has been an enemy for crop production for long time, is to respect the natural system. We have been studying many “natural farming” system organized by local farmers and experimental plots, and found that the soil contained high abundance and diversity of microbes and fauna, and there was large pool of nutrients in soil. This management allowed rapid soil improvement and efficient nutrient use by crops, thus it seems to be highly sustainable management of agricultural soil.

金子写真ー小