The risk posed by invasive alien species is determined primarily by two factors: distribution (occupancy) and abundance (density). However, most ecological studies use distribution data for monitoring and assessment programs, but few incorporate abundance data due to financial and logistical constraints. Failure to take into account invaders’ abundance may lead to imprecise pest risk assessments. Since 2003 as part of the Annual Pest Distribution Survey (APDS) exercise in the state of Queensland, Australia, government biosecurity officials have collected data on distribution and abundance of more than 100 established and emerging weeds. This data acquisition was done at spatial grid sizes of 17–50 × 17–50 km and across a very broad and varied geographical land area of ~2 × 106 km2. The datasets provide an opportunity to compare weed dynamics at large-medium spatial scales. Analysis of the APDS datasets indicated that weed distributions were highest in regions along the southern and central, coastal parts of Queensland, and decreased in the less populated inland (i.e. western) and northern parts of the state. Weed abundance showed no discernible landscape or regional trends. Positive distribution–abundance relationships were also detected at multiple spatial scales. Using both traits of weed abundance and distribution, we derived a measure of invasion severity, and constructed, for several (64) weed species, ‘space-for-time’ invasion curves. State-wide and in each of Queensland’s 10 regions, we also categorised the invasion stages of these weeds. At the grassroots of local government area or regional levels, the derived invasion curves and stage categories can provide policy direction for long-term management planning of Queensland’s priority weeds.

中文翻译：

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澳大利亚昆士兰杂草的入侵空间范围和入侵阶段分类

外来入侵物种带来的风险主要由两个因素决定：分布（占有率）和丰度（密度）。然而，大多数生态研究使用分布数据来进行监测和评估程序，但由于财务和后勤限制，很少包含丰度数据。不考虑入侵者的数量可能会导致有害生物风险评估不准确。自 2003 年以来，作为澳大利亚昆士兰州年度有害生物分布调查 (APDS) 活动的一部分，政府生物安全官员收集了 100 多种已建立和新出现的杂草的分布和丰度数据。该数据采集是在 17-50 × 17-50 公里的空间网格大小上完成的，并且跨越了约 2 × 106 平方公里的非常广泛和多样的地理土地区域。这些数据集提供了在大中空间尺度上比较杂草动态的机会。APDS 数据集的分析表明，昆士兰州南部和中部沿海地区的杂草分布最高，而人口较少的内陆（即西部）和北部地区则减少。杂草丰度没有显示出明显的景观或区域趋势。在多个空间尺度上也检测到正分布-丰度关系。使用杂草丰度和分布的两个特征，我们得出了入侵严重程度的度量，并为几种（64）种杂草构建了“时空”入侵曲线。在全州范围内以及昆士兰州的 10 个地区，我们还对这些杂草的入侵阶段进行了分类。在地方政府区域或区域层面的基层，