EAPSI: Understanding the Interactions Between Precipitation and Pastureland Management Strategies in Contributing to Locust Outbreaks

蝗虫成群影响着全世界60多个不同国家的许多人的生计。最近的研究表明，寄主植物中的低氮可能会引发蝗虫群。众所周知，集约化放牧会引发这种低氮条件。同样，过去的证据表明，降水增加可能会增加土壤氮素储备的耗竭速度，从而为蝗虫暴发创造有利条件。鉴于世界各地对动物产品的需求增加，以及该地区降雨增加的预期，了解这些相互作用尤为重要，如果不加以控制，可能会增加蝗虫暴发的频率和强度。该项目将与内蒙古草原生态系统研究站的乐康博士合作进行，中国说。IMGERS有几个地块处于长期管理之下，采用不同的放牧制度，是对蒙古蝗虫亚洲斑腿蝗虫的深入研究领域。本研究将采用配对样地设计，从连续放牧地块上的100万个圆形样地中抽样，放牧率分别为1.5和9只羊/公顷。每一块地将接受环境(1x)或补充(2x)降水处理。土壤NO3-和NH4+将作为响应变量，使用部分封闭的离子交换树脂膜在每一小区的两周间隔内收集。将测量草的氮和碳含量，以评估不同处理之间的植物养分吸收，并将使用田间捕获的受限蝗虫来评估寄主植物作为食物来源的最优性，以响应处理类型。该NSF EAPSI奖是与中国科技部合作资助的。

Locust swarms affect the livelihoods of many people worldwide, across more than 60 different countries. Recent research suggests locust swarms can be triggered in response to low nitrogen in their host plants. Intensive grazing is known to trigger these low-nitrogen conditions. Similarly, past evidence supports that increased precipitation may increase the rate at which soil nitrogen stocks are depleted, leading to favorable conditions for locust outbreaks. These interactions are particularly important to understand given increased worldwide demand for animal products and expectations for increased rainfall in the region, which unmanaged could increase the frequency and intensity of locust outbreaks. This project will be conducted in collaboration with Dr. Le Kang at the Inner Mongolia Grassland Ecosystem Research Station (IMGERS) in Inner Mongolia, China. IMGERS has several parcels under long-term management utilizing different grazing systems, and is an area of intensive research on the Mongolian locust, Oedaleus asiaticus.This study will utilize a paired plot design, sampling from 1m circular plots on continuously grazed parcels at 1.5 and 9 sheep/ha stocking rates. Each plot will receive either an ambient (1x) or supplemented (2x) precipitation treatment. Soil NO3- and NH4+ will serve as response variables, collected using partially enclosed ion-exchange resin membranes over two week intervals on each plot. Grass nitrogen and carbon content will be measured to assess plant nutrient uptake across treatments, and confined, field-captured locust nymphs will be used to assess the optimality of host plants as a food source in response to treatment type. This NSF EAPSI award is funded in collaboration with the Chinese Ministry of Science and Technology.