Fennell Mark, Wade Max, Bacon Karen L
AECOM, Cambridge, UK.
School of Geography, University of Leeds, Leeds, UK.
PeerJ. 2018 Jul 25;6:e5246. doi: 10.7717/peerj.5246. eCollection 2018.
(Japanese knotweed) is a well-known invasive alien species in the UK and elsewhere in Europe and North America. The plant is known to have a negative impact on local biodiversity, flood risk and ecosystem services; but in the UK it is also considered to pose a significant risk to the structural integrity of buildings that are within seven m of the above ground portions of the plant. This has led to the presence of the plant on residential properties regularly being used to refuse mortgage applications. Despite the significant socioeconomic impacts of such automatic mortgage option restriction, little research has been conducted to investigate this issue. The 'seven-m rule' is derived from widely adopted government guidance in the UK. This study considered if there is evidence to support this phenomenon in the literature, reports the findings of a survey of invasive species control contractors and property surveyors to determine if field observations support these assertions, and reports a case study of 68 properties, located on three streets in northern England where was recorded. Additionally, given the importance of proximity, the seven-m rule is also tested based on data collected during the excavation based removal of from 81 sites. No support was found to suggest that causes significant damage to built structures, even when it is growing in close proximity to them and certainly no more damage than other plant species that are not subject to such stringent lending policies. It was found that the seven-m rule is not a statistically robust tool for estimating likely rhizome extension. rhizome rarely extends more than four m from above ground plants and is typically found within two m for small stands and 2.5 m for large stands. Based on these findings, the practice of automatically restricting mortgage options for home buyers when is present, is not commensurate with the risk.
虎杖是英国以及欧洲和北美的其他地区一种广为人知的外来入侵物种。已知该植物会对当地生物多样性、洪水风险和生态系统服务产生负面影响；但在英国，它还被认为会对距离该植物地上部分7米范围内的建筑物结构完整性构成重大风险。这导致住宅物业上有这种植物的情况经常被用来拒绝抵押贷款申请。尽管这种自动限制抵押贷款选择的做法产生了重大的社会经济影响，但很少有研究对这个问题进行调查研究。“7米规则”源自英国广泛采用的政府指导意见。本研究考察了文献中是否有证据支持这一现象，报告了一项针对入侵物种控制承包商和房产测量师的调查结果，以确定实地观察是否支持这些说法，并报告了位于英格兰北部三条街道上记录有虎杖的68处房产的案例研究。此外，鉴于距离的重要性，还根据从81个地点挖掘清除虎杖期间收集的数据对“7米规则”进行了测试。没有发现证据表明虎杖会对建筑结构造成重大破坏，即使它生长在离建筑结构很近的地方，而且肯定不会比其他不受此类严格贷款政策限制的植物造成更多破坏。研究发现 “七米规则” 并不是一个统计上可靠的估计根茎可能延伸范围的工具。虎杖的根茎很少从地上植物延伸超过4米，对于小片植株通常在2米范围内，对于大片植株则在2.5米范围内。基于这些发现，当存在虎杖时自动限制购房者抵押贷款选择的做法与风险不相称。
