Khelifa Rassim, Mahdjoub Hayat, Baaloudj Affef, Cannings Robert A, Samways Michael J
Department of Zoology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
Biodiversity Research Centre, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
Insects. 2021 Apr 15;12(4):353. doi: 10.3390/insects12040353.
Agriculture can be pervasive in its effect on wild nature, affecting various types of natural habitats, including lotic ecosystems. Here, we assess the extent of agricultural expansion on lotic systems in Northern Africa (Algeria, Tunisia, and Morocco) and document its overlap with the distribution of an endemic damselfly, Selys, using species distribution modeling. We found that agricultural land cover increased by 321% in the region between 1992 and 2005, and, in particular, the main watercourses experienced an increase in agricultural land cover from 21.4% in 1992 to 78.1% in 2005, together with an increase in the intensity of 226% in agricultural practices. We used capture-mark-recapture (CMR) surveys in terrestrial habitats surrounding a stream bordered by grassland and cropland in northeastern Algeria to determine demographic parameters and population size, as well as cropland occupancy. CMR modeling showed that the recapture and survival probabilities had an average of 0.14 (95%CI: 0.14-0.17) and 0.86 (0.85-0.87), respectively. We estimated a relatively large population of (~1750 individuals) in terrestrial habitats. The occupancy of terrestrial habitats by adults was spatially structured by age. Our data suggest that has survived agricultural expansion and intensification better than other local odonate species, mainly because it can occupy transformed landscapes, such as croplands and grasslands.
农业对野生自然的影响可能无处不在，会影响各种类型的自然栖息地，包括流水生态系统。在此，我们评估了北非（阿尔及利亚、突尼斯和摩洛哥）流水系统中农业扩张的程度，并利用物种分布模型记录了其与一种特有豆娘（赛氏豆娘属）分布的重叠情况。我们发现，1992年至2005年期间，该地区的农业用地覆盖率增加了321%，特别是主要水道周边的农业用地覆盖率从1992年的21.4%增至2005年的78.1%，同时农业活动强度增加了226%。我们在阿尔及利亚东北部一片以草地和农田为边界的溪流周边的陆地栖息地进行了标记重捕（CMR）调查，以确定种群统计学参数、种群规模以及农田占有率。CMR模型显示，重捕概率和存活概率的平均值分别为0.14（95%置信区间：0.14 - 0.17）和0.86（0.85 - 0.87）。我们估计在陆地栖息地存在相对较大的种群（约1750只个体）。成年个体在陆地栖息地的占有率在空间上呈现出年龄结构。我们的数据表明，赛氏豆娘属比其他当地蜻蜓目物种在农业扩张和集约化过程中存活得更好，主要是因为它能够占据如农田和草地等已转变的景观。
