Differential response of barrier island dune grasses to species interactions and burial

Barrier islands are at the forefront of storms and sea-level rise. High disturbance regimes and sediment mobility make these systems sensitive and dynamic. Island foredunes are protective structures against storm-induced overwash that are integrally tied to dune grasses via biogeomorphic feedbacks. Shifts in dune grass dominance could influence dune morphology and susceptibility to overwash, altering island stability. In a glasshouse study, two dune grasses, Ammophila breviligulata and Uniola paniculata, were planted together and subjected to a 20 cm burial to quantify morphological and physiological responses. Burial had positive effects on both plants as indicated by increased electron transport rate and total biomass. Ammophila breviligulata performance declined when planted with U. paniculata. Uniola paniculata was not affected when planted with A. breviligulata but did have higher water use efficiency and nitrogen use efficiency. Planted in mixture, differential reallocation of biomass occurred between species potentially altering resource acquisition further. As U. paniculata migrates into A. breviligulata dominated habitat and A. breviligulata performance diminishes, biotic interactions between these and other species may affect dune formation and community structure. Our study emphasizes the importance of studying biotic interactions alongside naturally occurring abiotic drivers

Functional traits of expanding, thicket-forming shrubs: contrasting strategies between exotic and native species

Woody expansion has been documented for decades in many different systems globally, often yielding vast changes in ecosystem functioning. While causes and consequences of woody expansion have been well documented, few studies have addressed plant functional traits that promote dramatic and rapid expansion in range. Our objectives were to investigate plant functional traits that contribute to the colonization, rapid expansion, and thicket formation of an invasive, N-fixing shrub, Elaeagnus umbellata Thunb. (Elaeagnaceae), and a native, N-fixing shrub Morella cerifera (L.) Small (Myricaceae) and compare to native, sympatric, non-expanding shrub species. Quantified functional traits included morphological (e.g., specific leaf area, leaf area) and physiological characteristics (e.g., electron transport rate, hydraulic conductivity) and were linked to two primary resources: light and water, which directly influence plant growth. Elaeagnus umbellata and M. cerifera rely on different strategies to maximize carbon gain, yet resulting physiological efficiency is similar. Elaeagnus umbellata invests a substantial amount of energy into growth during a short amount of time (i.e., deciduous growing season), using an acquisitive trait strategy to outcompete co-occurring woody species, while M. cerifera is productive year-round and uses a combination of conservative and acquisitive traits to outcompete co-occurring woody species. The majority of quantified functional traits of E. umbellata and several of M. cerifera are indicative of efficient light capture, utilization, and internal water movement. These factors contribute to rapid range expansion and thicket formation by promoting enhanced productivity while simultaneously inhibiting colonization and expansion of co-occurring species. Suites of functional traits are important for expansive success and thicket formation, yet differences in functional traits represent alternative strategies for colonization, rapid expansion, and thicketization

Copyright in Memoriam

Can a government infringe upon a work dedicated to the memory of its people? The February 2010 Federal Circuit decision Gaylord v. United States addresses that question, but any satisfaction from the decision presupposes that the government should be held liable for such an infringement. Consistent with the 1976 Copyright Act, the Gaylord decision preserves the author\u27s rights, paying no regard to the identity of the audience or the infringer. From a policy perspective, however, the result is dubious. Arguably, if a work is a public memorial, and paid for with public funds, it should immediately enter the public domain. This Article focuses on one of the first, easy steps toward an expansion of the public domain: a policy decision that copyrights for creative works intended for the public are inherently unenforceable. Using Gaylord as an example, the Article examines expectations regarding the copyright of national monuments and memorials, as well as ownership of that copyright. It considers rights applicable to memorials, both under § 106 of the Copyright Act and § 106A, the Visual Artists Rights Act (VARA). It questions whether these works should be categorized as works of the United States government or, alternatively, as architectural works, and whether either answer would run afoul of the Berne Convention. Ultimately, it offers a solution under fair use that would create room in the public domain--not only for national monuments and memorials--but any work intended to belong to the public, for the public to use freely

Territorial fidelity and behavior of male guanacos in the Patagonia of southern Chile

We investigated site-fidelity and behavioral patterns of territorial male guanacos (Lama guanicoe) in Torres del Paine National Park, Chile. The study took place over a 10-year period, with extensive work in the final years, 1997-1999. Guanacos have a social system of resource-defense polygyny with fluid movement of females between male territories. After the annual winter migration, males establish territories in the spring and maintain them until late fall. Territorial males can be categorized into one of two social group types, Solo Territorial Males and Family Group Territorial Males. We collected data on territory type, location, size, and behavior for tagged, known-age males. Both Solo Territorial Males and Family Group Territorial Males were also observed to compare the activity time budgets of males in differing social groups and habitats. We compared individual male territorial philopatry between the mating (8 December - 11 January) and non-mating periods within the six-month territorial season (1 October - 15 March) each year and for individual male territory locations between multiple years.Most males remained in the same location both within and between territorial seasons. Solo Territorial Males and Family Group Territorial Males exhibit similar patterns, although some Solo Territorial Males shifted territorial locations between years. We found no difference in the activity time budgets of males based on social group type, total number of females present, or total number of guanacos present. There was a difference in the amount of time spent alert and in other activities based on habitat type. It is likely that territorial male guanaco behaviors are directly related to the resources defended rather than their ability to attract potential mates. Although it is not possible to predict breeding success of territorial males by behaviors, the high predictability of male territory sites within a given year and between years has short- and long-term benefits for research and conservation efforts