73 research outputs found

    Investigations of the Andean Past: Papers from the First Annual Northeast Conference on Andean Archaeology and Ethnohistory

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    The papers included in this volume represent fourteen of the twenty-three original papers presented at the First Annual Northeast Conference on Andean Archaeology and Ethnohistory held at Cornell University on November 13th and 14th, 1982. The papers are: The Preceramic Occupations of the Casma Valley, Peru by Michael A. Malpass, The Historical Development of a Coastal Andean Social Formation in Central Peru, 6000 to 500 B.C. by Thomas C. Patterson, Stone Tools in Ceramic Contexts: Exploring the Unstructured by Joan M. Gero, Possible Uses, Roles, and Meanings of Chavin-style Painted Textiles of South Coast Peru by Rebecca R. Stone, Megalithic Sites in the Nepena Valley, Peru by Richard E. Daggett, Huaca del Loro Revisited: The Nasca-Huarpa Connection by Allison C. Paulsen, Spatial Patterning and the Function of a Huari Architectural Compound by Christine C. Brewster-Wray, The Development of Huari Administrative Architecture by Lynda E. Spickard, Aspects of State Ideology in Huari and Tiwanaku Iconography: The Central Deity and the Sacrificer by Anita G. Cook, Shared Ideology and Parallel Political Development: Huari and Tiwanaku by William H. Isbell, Casma Incised Pottery: An Analysis of Collections from the Nepena Valley by Cheryl Daggett, High Altitude Land Use in the Huamachuco Area by T. McGreevy and R. Shaughnessy, La Lengua Pescadora: the Lost Dialect of Chimu Fishermen by Joel Rabinowitz, and The Chancas of Angaraes: 1450(?)--1765 by Paul H. Dillon.https://digitalcommons.library.umaine.edu/andean_past_special/1002/thumbnail.jp

    Multiple Facets of Biodiversity Drive the Diversity-Stability Relationship

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    A significant body of evidence has demonstrated that biodiversity stabilizes ecosystem functioning over time in grassland ecosystems. However, the relative importance of different facets of biodiversity underlying the diversity–stability relationship remains unclear. Here we used data from 39 biodiversity experiments and structural equation modeling to investigate the roles of species richness, phylogenetic diversity, and both the diversity and community-weighted mean of functional traits representing the ‘fast–slow’ leaf economics spectrum in driving the diversity–stability relationship. We found that high species richness and phylogenetic diversity stabilize biomass production via enhanced asynchrony. Contrary to our hypothesis, low phylogenetic diversity also enhances ecosystem stability directly, albeit weakly. While the diversity of fast–slow functional traits has a weak effect on ecosystem stability, communities dominated by slow species enhance ecosystem stability by increasing mean biomass production relative to the standard deviation of biomass over time. Our results demonstrate that biodiversity influences ecosystem stability via a variety of facets, thus highlighting a more multicausal relationship than has been previously acknowledged

    Global change effects on plant communities are magnified by time and the number of global change factors imposed

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    Global change drivers (GCDs) are expected to alter community structure and consequently, the services that ecosystems provide. Yet, few experimental investigations have examined effects of GCDs on plant community structure across multiple ecosystem types, and those that do exist present conflicting patterns. In an unprecedented global synthesis of over 100 experiments that manipulated factors linked to GCDs, we show that herbaceous plant community responses depend on experimental manipulation length and number of factors manipulated. We found that plant communities are fairly resistant to experimentally manipulated GCDs in the short term (<10 y). In contrast, long-term (≥10 y) experiments show increasing community divergence of treatments from control conditions. Surprisingly, these community responses occurred with similar frequency across the GCD types manipulated in our database. However, community responses were more common when 3 or more GCDs were simultaneously manipulated, suggesting the emergence of additive or synergistic effects of multiple drivers, particularly over long time periods. In half of the cases, GCD manipulations caused a difference in community composition without a corresponding species richness difference, indicating that species reordering or replacement is an important mechanism of community responses to GCDs and should be given greater consideration when examining consequences of GCDs for the biodiversity–ecosystem function relationship. Human activities are currently driving unparalleled global changes worldwide. Our analyses provide the most comprehensive evidence to date that these human activities may have widespread impacts on plant community composition globally, which will increase in frequency over time and be greater in areas where communities face multiple GCDs simultaneously

    Moving in the anthropocene: global reductions in terrestrial mammalian movements

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    Animal movement is fundamental for ecosystem functioning and species survival, yet the effects of the anthropogenic footprint on animal movements have not been estimated across species. Using a unique GPS-tracking database of 803 individuals across 57 species, we found that movements of mammals in areas with a comparatively high human footprint were on average one-half to one-third the extent of their movements in areas with a low human footprint. We attribute this reduction to behavioral changes of individual animals and to the exclusion of species with long-range movements from areas with higher human impact. Global loss of vagility alters a key ecological trait of animals that affects not only population persistence but also ecosystem processes such as predator-prey interactions, nutrient cycling, and disease transmission

    Long-term Site Fidelity and Individual Home Range Shifts in Lophocebus albigena

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    We investigated long-term site fidelity of gray-cheeked mangabey (Lophocebus albigena) groups in Kibale National Park, Uganda. Concurrently, we monitored shifts in home range by individual females and subadult and adult males. We documented home range stability by calculating the area of overlap in successive years, and by recording the drift of each group’s monthly centroid from its initial location. Home ranges remained stable for 3 of our 4 groups (overlap over 10 yr >60%). Core areas were more labile, but group centroids drifted an average of only 530 m over the entire decade. Deviations from site fidelity were associated with dispersal or group fission. During natal dispersal, subadult males expanded their home ranges over many months, settling ≤4 home ranges away. Adult males, in contrast, typically dispersed within a few days to an adjacent group in an area of home range overlap. Adult males made solitary forays, but nearly always into areas used by their current group or by a group to which they had previously belonged. After secondary dispersal, they expanded their ranging in the company of their new group, apparently without prior solitary exploration of the new area. Some females also participated in home range shifts. Females shifted home ranges only within social groups, in association with temporary or permanent group splits. Our observations raise the possibility that male mangabeys use a finder-joiner mechanism when moving into new home ranges during secondary dispersal. Similarly, females might learn new resource locations from male immigrants before or during group fission

    Social Bonding and Nurture Kinship: Compatibility between Cultural and Biological Approaches

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