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Author (up) Lopatin, J.; Araya-Lopez, R.; Galleguillos, M.; Perez-Quezada, J.F.
Title Disturbance alters relationships between soil carbon pools and aboveground vegetation attributes in an anthropogenic peatland in Patagonia Type
Year 2022 Publication Ecology And Evolution Abbreviated Journal Ecol. Evol.
Volume 12 Issue 3 Pages e8694
Keywords growth forms; management; plant functional types; PLS path modeling; structural equation modeling
Abstract Anthropogenic-based disturbances may alter peatland soil-plant causal associations and their ability to sequester carbon. Likewise, it is unclear how the vegetation attributes are linked with different soil C decomposition-based pools (i.e., live moss, debris, and poorly- to highly-decomposed peat) under grassing and harvesting conditions. Therefore, we aimed to assess the relationships between aboveground vegetation attributes and belowground C pools in a Northern Patagonian peatland of Sphagnum magellanicum with disturbed and undisturbed areas. We used ordination to depict the main C pool and floristic gradients and structural equation modeling (SEM) to explore the direct and indirect relationships among these variables. In addition, we evaluated whether attributes derived from plant functional types (PFTs) are better suited to predict soil C pools than attributes derived from species gradients. We found that the floristic composition of the peatland can be classified into three categories that follow the C pool gradient. These categories correspond to (1) woody species, such as Baccharis patagonica, (2) water-logged species like Juncus procerus, and (3) grasslands. We depicted that these classes are reliable indicators of soil C decomposition stages. However, the relationships change between management. We found a clear statistical trend showing a decrease of live moss, debris, and poorly-decomposed C pools in the disturbed area. We also depicted that plant diversity, plant height, and PFT composition were reliable indicators of C decomposition only under undisturbed conditions, while the species-based attributes consistently yielded better overall results predicting soil C pools than PFT-based attributes. Our results imply that managed peatlands of Northern Patagonia with active grassing and harvesting activities, even if small-scaled, will significantly alter their future C sequestration capacities by decreasing their live and poorly-decomposed components. Finally, aboveground vegetation attributes cannot be used as proxies of soil C decomposition in disturbed peatlands as they no longer relate to decomposition stages.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2045-7758 ISBN Medium
Area Expedition Conference
Notes WOS:000775192200010 Approved
Call Number UAI @ alexi.delcanto @ Serial 1559
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Author (up) 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
Year 2023 Publication Ecological Indicators Abbreviated Journal Ecol. Indic.
Volume 153 Issue 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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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1470-160X ISBN Medium
Area Expedition Conference
Notes WOS:001010662300001 Approved
Call Number UAI @ alexi.delcanto @ Serial 1824
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Author (up) Perez-Quezada, J.F.; Perez, C.A.; Brito, C.E.; Fuentes, J.P.; Gaxiola, A.; Aguilera-Riquelme, D.; Lopatin, J.
Title Biotic and abiotic drivers of carbon, nitrogen and phosphorus stocks in a temperate rainforest Type
Year 2021 Publication Forest Ecology and Management Abbreviated Journal Forest. Ecol. Manag.
Volume 494 Issue Pages 119341
Keywords EPIPHYTIC LICHEN BIOMASS; OLD-GROWTH FORESTS; N-P STOICHIOMETRY; SOIL-CARBON; CHILOE ISLAND; STAND DEVELOPMENT; LITTER DECOMPOSITION; ABOVEGROUND BIOMASS; USE EFFICIENCIES; ORGANIC-MATTER
Abstract Forest ecosystems are recognized for their large capacity to store carbon (C) in their aboveground and belowground biomass and soil pools. While the distribution of C among ecosystem pools has been extensively studied, less is known about nitrogen (N) and phosphorus (P) pools and how these stocks relate to each other. There is also a need to understand how biotic and abiotic ecosystem properties drive the magnitude and distribution of CN-P stocks. We studied a temperate rainforest in southern South America to answer the following questions: 1) how are C-N-P total stocks distributed among the different ecosystem pools?, 2) how do C:N, C:P and N:P ratios vary among ecosystem pools?, and 3) which are the main biotic and abiotic drivers of C-N-P stocks? We established 33 circular plots to estimate C, N, and P stocks in different pools (i.e. trees, epiphytes, understory, necromass, leaf litter, and soil) and a set of biotic (e.g., tree density and richness) and abiotic variables (e.g., air temperature, humidity and soil depth). We used structural equation modeling to identify the relative importance of environmental drivers on C-N-P stocks. We found that total ecosystem stocks (mean +/- SE) were 1062 +/- 58 Mg C ha-1, 28.8 +/- 1.5 Mg N ha-1, and 347 +/- 12.5 kg P ha-1. The soil was the largest ecosystem pool, containing 68%, 92%, and 73% of the total C, N, and P stocks, respectively. Compared to representative temperate forests, the soil of this forest contains the largest concentrations and stocks of C and N. The low P stock and wide soil C:P and N:P ratios suggest that P may be limiting forest productivity. The ecosystem C-N-P stocks were mainly driven by abiotic properties measured in the study area, however for N stocks, variables such as plant diversity and canopy openness were also relevant. Our results provide evidence about the importance not only of understanding the differences in C, N, and P stocks but also of the factors that drive such differences. This is key to inform conservation policies related to preserving old-growth forests in southern South America, which indeed are facing a rapid land-use change process.
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0378-1127 ISBN Medium
Area Expedition Conference
Notes WOS:000657603300010 Approved
Call Number UAI @ alexi.delcanto @ Serial 1421
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Author (up) Perez-Quezada, J.F.; Trejo, D.; Lopatin, J.; Aguilera, D.; Osborne, B.; Galleguillos, M.; Zattera, L.; Celis-Diez, J.L.; Armesto, J.J.
Title Comparison of carbon and water fluxes and the drivers of ecosystem water use efficiency in a temperate rainforest and a peatland in southern South America Type
Year 2024 Publication Biogeosciences Abbreviated Journal Biogeosciences
Volume 21 Issue 5 Pages 1371-1389
Keywords EDDY-COVARIANCE; SEVERE DROUGHT; SAP FLUXE; VAPOTRANSPIRATION; CLIMATE; BALANCE; TRANSPIRATION; RICHNESS; EXCHANGE; TREES
Abstract The variability and drivers of carbon and water fluxes and their relationship to ecosystem water use efficiency (WUE) in natural ecosystems of southern South America are still poorly understood. For 8 years (2015-2022), we measured carbon dioxide net ecosystem exchange (NEE) and evapotranspiration (ET) using eddy covariance towers in a temperate rainforest and a peatland in southern Chile. NEE was partitioned into gross primary productivity (GPP) and ecosystem respiration ( R eco ), while ET was partitioned into evaporation ( E ) and transpiration ( T ) and used to estimate different expressions of ecosystem WUE. We then used the correlation between detrended time series and structural equation modelling to identify the main environmental drivers of WUE, GPP, ET, E and T . The results showed that the forest was a consistent carbon sink ( – 486 +/- 23 g C m – 2 yr – 1 ), while the peatland was, on average, a small source (33 +/- 21 g C m – 2 yr – 1 ). WUE is low in both ecosystems and likely explained by the high annual precipitation in this region ( similar to 2100 mm). Only expressions of WUE that included atmospheric water demand showed seasonal variation. Variations in WUE were related more to changes in ET than to changes in GPP, while T remained relatively stable, accounting for around 47 % of ET for most of the study period. For both ecosystems, E increased with higher global radiation and higher surface conductance and when the water table was closer to the surface. Higher values for E were also found with increased wind speeds in the forest and higher air temperatures in the peatland. The absence of a close relationship between ET and GPP is likely related to the dominance of plant species that either do not have stomata (i.e. mosses in the peatland or epiphytes in the forest) or have poor stomatal control (i.e. anisohydric tree species in the forest). The observed increase in potential ET in the last 2 decades and the projected drought in this region suggests that WUE could increase in these ecosystems, particularly in the forest, where stomatal control may be more significant.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1726-4170 ISBN Medium
Area Expedition Conference
Notes WOS:001190653700001 Approved
Call Number UAI @ alexi.delcanto @ Serial 1976
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