Brown Lee E, Johnston Kerrylyn, Palmer Sheila M, Aspray Katie L, Holden Joseph
School of Geography and water@leeds, University of Leeds, Leeds, United Kingdom.
PLoS One. 2013 Nov 21;8(11):e81023. doi: 10.1371/journal.pone.0081023. eCollection 2013.
Catchment-scale land-use change is recognised as a major threat to aquatic biodiversity and ecosystem functioning globally. In the UK uplands rotational vegetation burning is practised widely to boost production of recreational game birds, and while some recent studies have suggested burning can alter river water quality there has been minimal attention paid to effects on aquatic biota. We studied ten rivers across the north of England between March 2010 and October 2011, five of which drained burned catchments and five from unburned catchments. There were significant effects of burning, season and their interaction on river macroinvertebrate communities, with rivers draining burned catchments having significantly lower taxonomic richness and Simpson's diversity. ANOSIM revealed a significant effect of burning on macroinvertebrate community composition, with typically reduced Ephemeroptera abundance and diversity and greater abundance of Chironomidae and Nemouridae. Grazer and collector-gatherer feeding groups were also significantly less abundant in rivers draining burned catchments. These biotic changes were associated with lower pH and higher Si, Mn, Fe and Al in burned systems. Vegetation burning on peatland therefore has effects beyond the terrestrial part of the system where the management intervention is being practiced. Similar responses of river macroinvertebrate communities have been observed in peatlands disturbed by forestry activity across northern Europe. Finally we found river ecosystem changes similar to those observed in studies of wild and prescribed forest fires across North America and South Africa, illustrating some potentially generic effects of fire on aquatic ecosystems.
集水区尺度的土地利用变化被认为是全球水生生物多样性和生态系统功能的主要威胁。在英国高地，为了增加休闲猎鸟的产量，广泛实行轮作植被焚烧，虽然最近的一些研究表明焚烧会改变河流水质，但对水生生物群的影响却很少受到关注。我们在2010年3月至2011年10月期间研究了英格兰北部的十条河流，其中五条河流经已焚烧集水区，五条河流经未焚烧集水区。焚烧、季节及其相互作用对河流大型无脊椎动物群落有显著影响，流经已焚烧集水区的河流分类丰富度和辛普森多样性显著较低。ANOSIM分析显示焚烧对大型无脊椎动物群落组成有显著影响，通常蜉蝣目昆虫的丰度和多样性降低，摇蚊科和叉襀科昆虫的丰度增加。在流经已焚烧集水区的河流中，植食性和集食性摄食群体的数量也显著较少。这些生物变化与已焚烧系统中较低的pH值以及较高的硅、锰、铁和铝含量有关。因此，泥炭地的植被焚烧不仅对实施管理干预的系统陆地部分有影响。在北欧受林业活动干扰的泥炭地中也观察到了河流大型无脊椎动物群落的类似反应。最后，我们发现河流生态系统的变化与北美和南非对野火和规定火烧的研究中观察到的变化相似，这说明了火灾对水生生态系统的一些潜在普遍影响。
