Litter decomposition is a fundamental ecosystem process and service that supplies nutrients to the soil. Although decomposition rate is influenced by litter quality, climatic conditions, the decomposer community and vegetation type in non-urban ecosystems, little is known about the degradation of different organic matter types in urban settings. We investigated the decomposition rates of recalcitrant (wood sticks for 4 years) and labile litter (green tea leaves in pyramid-shaped teabags for 3 years) in urban habitats that differed in level of management and disturbance. We found that recalcitrant woody material decomposed slower in urban habitat types (ca. 60–75% mass loss after 4 years in remnant spruce forests, park lawns, ruderal habitats) than in natural to semi-natural spruce forest soils (84% mass loss) outside the city. Labile tea litter, however, decomposed faster in typical open urban habitats (70% mass loss after 3 years in park lawns, ruderal habitats) than in forested habitats (60% mass loss in semi-natural and remnant spruce forests), with a remarkable dichotomy in decomposition rate between open and forested habitats. We suggest that the slower rate of wood decomposition in the city relates to its depauperate saprotrophic fungal community. The faster rate of labile litter decomposition in open habitats is difficult to explain, but is potentially a consequence of environmental factors that support the activity of bacteria over fungi in open habitats. We propose that the reintroduction of decaying woody material into the urban greenspace milieu could increase biodiversity and also improve the ability of urban soils to decompose an array of organic material entering the system. This reintroduction of decaying woody material could either occur by leaving cut logs – due to management – in urban remnant forests, which has been shown to be accepted as natural features by residents in Fennoscandian cities, and by placing logs in urban parks in ways that communicate their intentional use as part of urban landscape design and management.

凋落物分解是向土壤提供养分的基本生态系统过程和服务。尽管分解速率受垃圾质量，气候条件，分解剂群落和非城市生态系统中植被类型的影响，但对于城市环境中不同有机物类型的降解知之甚少。我们调查了在管理和干扰水平不同的城市生境中的顽固性分解物（木棍4年）和不稳定垃圾（金字塔形茶袋中的绿茶叶3年）的分解率。我们发现顽固性木本材料在城市栖息地类型中的分解速度较慢（在剩余的云杉林，公园草坪，石生境中，四年后的质量损失约为60–75％），比自然至半天然云杉林土壤的分解速度更慢（质量损失为84％） ） 城外。不稳定的茶渣，但是，在典型的开放式城市栖息地中分解（在公园的草坪，绿地栖息地中放置3年后，其质量损失为70％）比在森林栖息地中（半天然和残留的云杉林中的质量损失为60％）要快，分解速率非常明显在开阔的森林栖息地之间。我们建议，城市中木材分解的速度较慢与其腐烂的腐生真菌群落有关。在开放栖息地中不稳定凋落物分解的速度较快，这很难解释，但可能是由于环境因素支持开放栖息地中细菌对真菌的活性所致。我们建议将腐烂的木质材料重新引入到城市绿地环境中可以增加生物多样性，还可以提高城市土壤分解进入系统的一系列有机材料的能力。