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Plant reintroductions have become an important component of species recovery strategies. To favor establishment and survival rates of reintroduced specimens, the use of mature individuals is often recommended. Producing individuals from seed can be challenging, because little is known about the germination requirements of many endangered species. Here, we investigated whether Carex lupuliformis achenes can be germinated at high rates under semi-controlled ex situ conditions. More specifically, we aimed to determine which simple stratification technique allows higher/faster germination rates, whether scarification speeds up the germination process, and which light intensity allows higher/faster germination rates. We found that a brief cold-wet stratification (one month in wet sand) increases the likelihood that C. lupuliformis achenes will germinate, but that a similar germination rate can be obtained by storing achenes at 4°C for six months in a plastic bag. Although scarification did not affect final germination rates, scarified achenes germinated significantly faster than unscarified ones. Finally, we found that a light intensity of 25% resulted in significantly higher final germination rates than lower light intensities. In conclusion, our experiments showed that C. lupuliformis is easy to propagate ex situ, as a variety of treatments resulted in relatively high germination rates.
The phenomenon of layering in trees involves the production of adventitious roots by low-growing lateral branches and their subsequent reorientation from horizontal to vertical. This study provides the first documentation of layering in any natural populations of eastern hemlock, Tsuga canadensis. Twelve layered hemlock clumps, consisting of 5 to 20 layered branch stems originating from a parent tree, were observed on the upper slopes of Wachusett Mountain in central Massachusetts. Layered hemlocks ranged from 7 to 17 m tall, and several layered branches produced second-generation layers. Harsh growing conditions, slow hemlock growth, and the open habitat associated with small-statured hardwood species and exposed bedrock allowed the hemlocks to retain their lower branches for extended periods of time. Fallen limbs and debris associated with past disturbances pinned these branches to the ground and likely set the stage for layering. The production of physiologically rejuvenated hemlock ramets through the layering process serves to extend the life-span of hemlock genets, expand their spatial dominance of the area, and promote their persistence under stressful growing conditions.
Erythronium americanum (Trout Lily) is a common spring ephemeral in northeast forests. It is important to nutrient retention in the spring, serves as food for wildlife and has aesthetic value with its early visibility and attractive flower. Corms of E. americanum survive the winter and summer in a dormant state, and the plants expend energy using droppers to send corms deeper at the end of their active period in the spring. I investigated the importance of depth in soil to corm survival by planting ten corms at 1, 5 and 10 cm depth for both the summer of 2014 and the winter of 2014–2015 in a hardwood forest in southeastern New York State. In the winter, a second treatment was added in which snow was removed after each storm for the first and last four weeks of snow cover. During the summer, corms at 5 and 10 cm depth had a significantly greater chance of survival to fall than those at 1 cm. During the winter, corm survival to spring was higher at 10 cm depth than at 1 or 5 cm depth in the control, and lowest at the 1 cm depth in the snow removal treatment. Collectively, shallow corms will have a lower survival rate than deeper corms, and reduced winter snow fall will significantly reduce survival of corms at shallow depths. Mechanisms of mortality underlying this pattern need further investigation.