| Records |
| Author |
Perez-Quezada, J.F.; Lopatin, J.; Donoso, M.R.; Hurtado, C.; Reyes, I.; Seguel, O.; Bown, H.E. |
| Title |
Indicators of ecosystem degradation along an elevational gradient in the Mediterranean Andes |
Type |
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| Year |
2023 |
Publication  |
Ecological Indicators |
Abbreviated Journal |
Ecol. Indic. |
| Volume |
153 |
Issue |
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Pages |
110388 |
| Keywords |
Andes mountain range; Topographic gradient; Disturbance; Disturbance indicator; Indicator plant species; Perturbation |
| Abstract |
Successful restoration measures need a good understanding of how the composition, structure, and functioning of ecosystems change with degradation and what the best indicators of these changes are. To answer these questions, we worked on four ecosystem types in the Mediterranean Andes mountains in central Chile (from sclerophyllous forest to Andean shrublands), which represent an elevational gradient from 700 to 3,250 m. We sampled three plots on each of the three degradation levels (low, medium, and high) for each ecosystem at increasing distances from goat corrals. We measured 35 indicators that describe vegetation (14), soil (15), and ecosystem processes (6) for one growing season. Degradation caused a decrease in shrub cover, shrub productivity, the Normalized Community Structure Integrity Index (CSIIn), litter depth, total soil nitrogen and C/N ratio, and an increase in clay content. Plant species indicating low degradation were consistently native woody species. When comparing ecosystems (i.e., at different elevations) against the type of variable, process-based indicators showed more statistically significant differences. Based on their consistency across ecosystems and ease of measurement, we recommend using shrub cover and litter depth as indicators of degradation. Finally, we concluded that ecosystems are highly degraded when vegetation- and process-based indicators change – 60% or when soil indicators change – 25%. These results could also be used to set goals for restoration projects in these mountain ecosystems. |
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| ISSN |
1470-160X |
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| Notes |
WOS:001010662300001 |
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| Call Number |
UAI @ alexi.delcanto @ |
Serial |
1824 |
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| Author |
Valdivia, N.; Aguilera, MA.; Broitman, BR. |
| Title |
High Dimensionality of the Stability of a Marine Benthic Ecosystem |
Type |
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| Year |
2021 |
Publication |
Frontiers in Marine Science |
Abbreviated Journal |
Front. Mar. Sci. |
| Volume |
7 |
Issue |
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Pages |
569650 |
| Keywords |
metacommunity; species extinction; field experiment; rocky intertidal communities; disturbance |
| Abstract |
Stability is a central property of complex systems and encompasses multiple dimensions such as resistance, resilience, recovery, and invariability. How these dimensions correlate among them is focus of recent ecological research, but empirical evidence at regional scales, at which conservation decisions are usually made, remains absent. Using a field-based manipulative experiment conducted in two marine intertidal regions, we analyze the correlations among different aspects of stability in functioning (community cover) and composition of local communities facing a press disturbance. The experiment involved the removal of the local space-dominant species for 35 months in eight sites under different environmental regimes in northern- and southern-central Chile (ca. 30 and 40 degrees S, respectively). After the disturbance, the magnitude of the initial responses and the recovery patterns were similar among communities dominated by different species, but varied between the functional and compositional response variables, and among four dimensions of stability. The recovery trajectories in function and composition remained mostly uncorrelated across the system. Yet, larger initial functional responses were associated with faster recovery trajectories-high functional resilience, in turn, was associated with both, high and low variability in the pattern of recovery. Finally, the compositional stability dimensions were independent from each other. The results suggest that varying community compositions can perform similar levels of functioning, which might be the result of strong compensatory dynamics among species competing for space in these communities. Knowledge of several, and sometimes independent, aspects of stability is mandatory to fully describe the stability of complex ecological systems. |
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2296-7745 |
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| Notes |
WOS:000612359300001 |
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UAI @ alexi.delcanto @ |
Serial |
1339 |
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| Author |
Peters, A.A.; Vargas, FJ.; Garrido, C.; Andrade, C.; Villenas, F. |
| Title |
PL-TOON: A Low-Cost Experimental Platform for Teaching and Research on Decentralized Cooperative Control |
Type |
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| Year |
2021 |
Publication |
Sensors |
Abbreviated Journal |
Sensors |
| Volume |
21 |
Issue |
6 |
Pages |
2072 |
| Keywords |
DISTURBANCE PROPAGATION; MOBILE ROBOT; SYSTEMS; EDUCATION |
| Abstract |
In this paper, we present the development of a low-cost multi-agent system experimental platform for teaching, and research purposes. The platform consists of train-like autonomous agents equipped with local speed estimation, distance sensing to their nearest predecessor, and wireless communications with other agents and a central coordinator. The individual agents can be used for simple PID experiments in a classroom or laboratory setting, while a collection of agents are capable of performing decentralized platooning with cooperative adaptive cruise control in a variety of settings, the latter being the main goal of the platform. The agents are built from low cost components and programmed with open source software, enabling teaching experiences and experimental work with a larger number of agents that would otherwise be possible with other existing solutions. Additionally, we illustrate with experimental results some of the teaching activities that the platform is capable of performing. |
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1424-8220 |
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WOS:000652717700001 |
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| Call Number |
UAI @ alexi.delcanto @ |
Serial |
1391 |
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