春の日本の水田

片山直樹氏らの日本での研究によると、有機稲作は従来の農業よりも多くの植物、クモ、トンボ、カエル、水鳥を支えている。 A version of this post in English is available here. 20世紀半ば以降の農業の集約化と、より近年の耕作放棄は、農地の生物多様性に対する大きな脅威となっている。有機農法と低投入型農法(化学合成農薬および肥料の削減)は、農地の生物多様性を、進行中の生息地の損失と劣化から守る手段として期待されている。それにもかかわらず、有機農法や低投入型農法が生物多様性にもたらす利益についての知見は、主要な米の生産地であるアジアでは非常に少ない。 著者らの研究では、有機農法や低投入型農法で増える可能性のある様々な生物群(植物、クモ、トンボ、カエル、魚、および鳥)を、有機農法または低投入農法の水田で調査し、近隣の慣行農法の水田と比較した。1000以上の日本の圃場で現地調査を行った。日本では、主に地球温暖化防止や生物多様性保全のために、有機農法や低投入型農法を実施している農家に対して、国や自治体が支援を行っている(0.1 ha当たり最大8,000円=2019年5月21日時点で約72.6 USDまたは65.1 EURに相当)。 著者らは、有機農法の水田において、多くの生物群(在来およびレッドリスト植物、アシナガグモ属、アカネ属、およびトノサマガエル属)の種数・個体数が最も多くなることを実証した。水鳥の種数と個体数は、地域内の有機農法の実施面積に比例して増加し、これは広範囲で食物量を高めることの重要性を示唆した。また低投入型農法の水田は、慣行農法の水田よりも植物の種数とアシナガグモ属・アカネ属の個体数が多かった。さらに著者らは、農業者へのインタビューを通じて収集した農地管理に関するデータを用いて、化学合成農薬の低減や回避だけでなく、輪作の非実施、畦畔植生の維持および空間的にまとまった有機農業の実施によって、生物多用性に配慮した稲作が可能になることを示した。 これらの結果から、慣行農法と比較して、有機および低投入型稲作が農地の生物多様性が豊かであることが明らかになった。これにより、日本で実施されている農業環境政策(有機・特別栽培等に対する交付金制度)の効果について、科学的な評価基盤を提供することができた。さらに、輪作を回避すること、畦畔植生を適当な高さに維持すること、および有機栽培を行う水田を空間的にまとめることも、特定の分類群の保全に有効であることがわかり、こうした取組の推進が望まれる。 全文を参照, 有機農法およびそれに関連する管理手法が複数の生物群に利益をもたらす:水田景観における大規模な野外調査, in Journal of Applied Ecology. Continue reading 春の日本の水田

On the benefits of organic farming: Japanese rice fields in spring

Based on their research in Japan, Naoki Katayama and colleagues highlight how organic rice farming supports more plants, spiders, dragonflies, frogs and waterbirds than conventional farming. A version of this post in Japanese is available here. The intensification of agriculture since the mid-20th century, and the more recent abandonment of farmlands, have presented major threats to farmland biodiversity. Organic farming and less strict low-input farming … Continue reading On the benefits of organic farming: Japanese rice fields in spring

Measuring the ‘urbanness’ of a bird community

Harnessing the power of global citizen science data sets to improve local understanding, Corey T. Callaghan (Centre for Ecosystem Science, UNSW Sydney) introduces the Urban Greenspace Integrity Index as a means to track restoration efforts in urban areas. Restoring urban biodiversity has many benefits (for examples, see here, here, or here), but what should we actually be focusing on in our restoration efforts? If we … Continue reading Measuring the ‘urbanness’ of a bird community

Traditional management systems maintain phylogenetically distinct rare species in semi-natural grasslands

Based on their research in Japan, Kei Uchida and colleagues, highlight why traditional land-use practices need to be upheld if we are to support biodiversity and rare species in semi-natural grasslands. We live in an era of rapidly changing land use. Semi-natural grasslands on the margins of agricultural lands were previously maintained by traditional extensive management practices. But, more recently, a decline in traditional land-use … Continue reading Traditional management systems maintain phylogenetically distinct rare species in semi-natural grasslands

Sustainable intensification: our quest for the ‘holy grail’

Is it possible to meet food demands and increase production without the damaging costs to the environment? Patrick White et al. tackle this challenge in their recently published research in the journal. As the world population grows, our finite land is put under increasing pressure to meet food demands. Historically we have increased agricultural yields by increasing the intensity of agricultural practices – for example … Continue reading Sustainable intensification: our quest for the ‘holy grail’

Integrating ecosystem services into environmental decision making

How can institutions and decision makers better work with practitioners to deliver an effective ecosystem services approach in a world of competing priorities? Read the questions posed by Alina Congreve and Iain Cross, and share your thoughts in the comments below. The related challenges of climate change and biodiversity conservation require decision makers to develop an effective range of policy solutions. One approach is to … Continue reading Integrating ecosystem services into environmental decision making

Spotlight: Managing biodiversity and ecosystem services in farmland landscapes

Issue 56:1 of Journal of Applied Ecology turns its focus to innovative developments in sustainable food production with the Spotlight, Landscape‐level design for managing biodiversity in agroecosystems. Associate Editor, Tomas Pärt and colleagues from The Landscape Ecology Network group at the Swedish University of Agricultural Sciences summarize the importance of this new collection of work. How should we use and manage agricultural landscapes for sustainable … Continue reading Spotlight: Managing biodiversity and ecosystem services in farmland landscapes

Fertilising with nutrient residues: a short-sighted solution for semi-natural grassland productivity?

Lauri Laanisto discusses their recent Commentary, Fertilising semi‐natural grasslands may cause long‐term negative effects on both biodiversity and ecosystem stability. Community ecology was once famously described as ‘collecting stamps’ by John Lawton, as every community is so different and unique in so many ways. Therefore, instead of making generalisations, one can only study unique communities the way a collector studies their unique collection – a very … Continue reading Fertilising with nutrient residues: a short-sighted solution for semi-natural grassland productivity?

Land use change and the interplay between functional and phylogenetic diversity in tropical forest birds

Philip Chapman comments on recent article, Contrasting impacts of land-use change on phylogenetic and functional diversity of tropical forest birds. It is increasingly recognised that biodiversity conservation needs to look beyond the goal of preserving species richness, to maintaining healthy functioning ecosystems and their evolutionary resilience in the face of environmental change. Species vary in evolutionary distinctness and the uniqueness of traits contributing to key ecological … Continue reading Land use change and the interplay between functional and phylogenetic diversity in tropical forest birds

Increasing the conservation value of commercial stands – with Spanish translation

Can plantation forests offer conservation value to some species? Guadalupe Peralta comments on recent article Plant, herbivore and parasitoid community composition in native Nothofagaceae forests vs. exotic pine plantations.  The authors have also provided a Spanish translation of this post. ‘Conservation value of exotic plantation forests’ is a controversial idea. The term conservation value of plantation forests does not refer to the need to preserve plantation forests … Continue reading Increasing the conservation value of commercial stands – with Spanish translation