scholarly journals Variable retention harvesting influences belowground plant-fungal interactions of Nothofagus pumilio seedlings in forests of southern Patagonia

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5008 ◽  
Author(s):  
Rebecca E. Hewitt ◽  
Donald Lee Taylor ◽  
Teresa N. Hollingsworth ◽  
Christopher B. Anderson ◽  
Guillermo Martínez Pastur
Keyword(s):  
Soil Moisture ◽  
Community Composition ◽  
Conservation Status ◽  
Tierra Del Fuego ◽  
Primary Forest ◽  
Nothofagus Pumilio ◽  
Variable Retention ◽  
Seedling Biomass ◽  
Rdna Sequencing ◽  
Southern Patagonia

Background The post-harvest recovery and sustained productivity of Nothofagus pumilio forests in Tierra del Fuego may be affected by the abundance and composition of ectomycorrhizal fungi (EMF). Timber harvesting alters EMF community structure in many managed forests, but the impacts of harvesting can vary with the management strategy. The implementation of variable retention (VR) management can maintain, increase, or decrease the diversity of many species, but the effects of VR on EMF in the forests of southern Patagonia have not been studied, nor has the role of EMF in the regeneration process of these forests. Methods We evaluated the effects of VR management on the EMF community associated with N. pumilio seedlings. We quantified the abundance, composition, and diversity of EMF across aggregate (AR) and dispersed (DR) retention sites within VR managed areas, and compared them to primary forest (PF) unmanaged stands. EMF assemblage and taxonomic identities were determined by ITS-rDNA sequencing of individual root tips sampled from 280 seedlings across three landscape replicates. To better understand seedling performance, we tested the relationships between EMF colonization, EMF taxonomic composition, seedling biomass, and VR treatment. Results The majority of EMF taxa were Basidiomycota belonging to the families Cortinariaceae (n = 29), Inocybaceae (n = 16), and Thelephoraceae (n = 8), which was in agreement with other studies of EMF diversity in Nothofagus forests. EMF richness and colonization was reduced in DR compared to AR and PF. Furthermore, EMF community composition was similar between AR and PF, but differed from the composition in DR. EMF community composition was correlated with seedling biomass and soil moisture. The presence of Peziza depressa was associated with higher seedling biomass and greater soil moisture, while Inocybe fibrillosibrunnea and Cortinarius amoenus were associated with reduced seedling biomass and lower soil moisture. Seedling biomass was more strongly related to retention type than EMF colonization, richness, or composition. Discussion Our results demonstrate reduced EMF attributes and altered composition in VR treatments relative to PF stands, with stronger impacts in DR compared to AR. This suggests that VR has the potential to improve the conservation status of managed stands by supporting native EMF in AR. Our results also demonstrate the complex linkages between retention treatments, fungal community composition, and tree growth at individual and stand scales.

Twelve-year dynamics of alien and native understorey plants following variable retention harvesting in Nothofagus pumilio forests in Southern Patagonia

2019 ◽  
Vol 449 ◽  
pp. 117447 ◽  
Author(s):  
Rosina Soler ◽  
Sabine B. Rumpf ◽  
Stefan Schindler ◽  
Guillermo Martínez Pastur ◽  
Marcelo Barrera ◽  
...  
Keyword(s):  
Nothofagus Pumilio ◽  
Variable Retention ◽  
Southern Patagonia ◽  
Variable Retention Harvesting ◽  
Understorey Plants

Timber management with variable retention in Nothofagus pumilio forests of Southern Patagonia

2009 ◽  
Vol 258 (4) ◽  
pp. 436-443 ◽  
Author(s):  
Guillermo Martínez Pastur ◽  
María Vanessa Lencinas ◽  
Juan Manuel Cellini ◽  
Pablo Luis Peri ◽  
Rosina Soler Esteban
Keyword(s):  
Nothofagus Pumilio ◽  
Timber Management ◽  
Variable Retention ◽  
Southern Patagonia

scholarly journals Disentangling Species Delineation and Guiding Conservation of Endangered Magnolias in Veracruz, Mexico

Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 673
Author(s):  
Fabián Augusto Aldaba Aldaba Núñez ◽  
Emily Veltjen ◽  
Esteban Manuel Martínez Martínez Salas ◽  
Marie-Stéphanie Samain
Keyword(s):  
Conservation Status ◽  
Full Range ◽  
Genetic Evidence ◽  
Primary Forest ◽  
Volcanic Area ◽  
Conservation Units ◽  
Separate Species ◽  
Representative Sampling ◽  
Conservation Projects ◽  
Very High

The Mexican state of Veracruz has suffered very high deforestation rates in the last few decades, and despite the establishment of protected areas and conservation projects, primary forest is now mainly persisting in mostly small, scattered, fragmented remnants. New species of Magnolia section Talauma in this state have been described with little to no reference to the already existing ones, potentially resulting in over-splitting, obscuring their taxonomic delineation and conservation status, and consequently conservation programs. To study the conservation units and their genetic diversity, we here employ 15 microsatellite markers on a highly representative sampling of 254 individuals of what are presumed to be five Magnolia species. The results support at least three species and maximum five main conservation units. We propose downgrading the latter to four, given morphological, ecological, demographical, and geographical considerations. Two out of the three sympatrically occurring species in the rainforest in the Los Tuxtlas volcanic area have weak genetic evidence to be considered separate species. Similarly, the individuals in the Sierra de Zongolica in central Veracruz, who bear a very high morphological and genetic similarity to Magnolia mexicana, have weak genetic evidence to be recognised as a separate species. Nonetheless, the individuals could be identified as Magnolia decastroi based on morphology, and further research including the full range of this species is recommended.

Hieracium pilosella invasion in the Tierra del Fuego steppe, Southern Patagonia

2009 ◽  
Vol 12 (8) ◽  
pp. 2523-2535 ◽  
Author(s):  
P. A. Cipriotti ◽  
R. B. Rauber ◽  
M. B. Collantes ◽  
K. Braun ◽  
C. Escartín
Keyword(s):  
Tierra Del Fuego ◽  
Hieracium Pilosella ◽  
Southern Patagonia

Four Centuries of Summer Temperature Changes in Tierra Del Fuego: Atmospheric Drivers and Tree-Ring Reconstruction From the Southernmost Forests of the World

2021 ◽  
Author(s):  
Vladimir Matskovsky ◽  
Fidel A. Roig ◽  
Mauricio Fuentes ◽  
Irina Korneva ◽  
Diego Araneo ◽  
...  
Keyword(s):  
Tree Ring ◽  
Ring Width ◽  
Temperature Reconstruction ◽  
Summer Temperature ◽  
Temperature Variability ◽  
Tierra Del Fuego ◽  
Climate Modelling ◽  
Least Squares Regression ◽  
Nothofagus Pumilio ◽  
The World

Abstract Proxy climate records, such as those derived from tree rings, are necessary to extend relatively short instrumental meteorological observations into the past. Tierra del Fuego is the most austral territory with forests in the world, situated close to the Antarctic Peninsula, which makes this region especially interesting for paleoclimatic research. However, high-quality, high-resolution summer temperature reconstruction are lacking in the region. In this study we used 63 tree-ring width chronologies of Nothofagus pumilio and Nothofagus betuloides and partial least squares regression (PLSR) to produce annually resolved December-to-February temperature reconstruction since AD 1600 which explains up to 65% of instrumental temperature variability. We also found that observed summer temperature variability in Tierra del Fuego is primarily driven by the fluctuations of atmospheric pressure systems both in the South Atlantic and South Pacific, while it is insignificantly correlated to major hemispheric modes: ENSO and SAM. This fact makes our reconstruction important for climate modelling experiments, as it represents specific regional variability. Our reconstruction can be used for direct comparison with model outputs to better understand model limitations or to tune a model or contribute to larger scale reconstructions based on paleoclimatic data assimilation. Moreover, we showed that PLSR has improved performance over principal component regression (PCR) in the case of multiple tree-ring predictors. According to these results, PLSR may be a preferable method over PCR for the use in automated tree-ring based reconstruction approaches, akin widely used point-by-point regression.

Salicornia cuscoensis (Amaranthaceae/Chenopodiaceae), a new species from Peru (South America)

Phytotaxa ◽  
2017 ◽  
Vol 319 (3) ◽  
pp. 254 ◽  
Author(s):  
M. ÁNGELES ALONSO ◽  
MANUEL B. CRESPO ◽  
HELMUT FREITAG
Keyword(s):  
New Species ◽  
South America ◽  
Morphological Characters ◽  
Tierra Del Fuego ◽  
South American ◽  
Habitat Distribution ◽  
Closely Related Species ◽  
Molecular Analyses ◽  
Southern Patagonia ◽  
A New Species

The name Salicornia cuscoensis given to a plant from high Andean saltmarshes near Cusco [Cuzco] and Ayacucho, Peru (South America) is validated by a diagnosis and description. The main morphological characters that separate S. cuscoensis from other closely related species are creeping habit, delicate branches, inflorescence of short and thin spikes, and seed indumentum. The new species clearly differs from other perennial Salicornia taxa growing in high Andean saltmarshes such as S. pulvinata and S. andina. The former forms small compact cushions producing very short, few-flowered inflorescences. The latter shows woody stems and forms larger rounded carpets. Morphologically, S. cuscoensis is also similar to S. magellanica, a species growing along the seashore in southern Patagonia and Tierra del Fuego, but the latter has shorter and wider inflorescences and larger seeds with a different type and arrangement of indumentum. Molecular analyses also supported the separation of S. cuscoensis. Data on habitat, distribution and phylogenetic relationships are presented for the new species and its relatives, and an identification key is given for the South American taxa of the genus Salicornia.

scholarly journals HISTORIA DEL BOSQUE EN EL CENTRO DE TIERRA DEL FUEGO, ARGENTINA

2019 ◽  
Vol 2 (3) ◽  
pp. 25-36
Author(s):  
Lidia S. Burry ◽  
Matilde E. Trivi de Mandri
Keyword(s):  
Tierra Del Fuego ◽  
Nothofagus Pumilio

Nothofagus pumilio es la especie forestal nativa de mayor importancia en Tierra del Fuego ocupa un área de 214,000 ha, y es la principal fuente de madera. En este trabajo se aportan elementos para la reconstrucción de la historia del bosque de Nothofagus pumilio en el centro de la Isla Grande de Tierra del Fuego, extremo austral del continente americano. La reconstrucción se realizó mediante el análisis polínico de tres segmentos de una columna de sedimentos, proveniente de una turbera de Sphagnum. Los granos de polen se extrajeron con técnicas físicas y químicas; se determinaron, contaron y los datos porcentuales se trataron estadísticamente mediante un análisis de ordenación, para lo cual se usó el análisis de correspondencia (CA programme). Los cambios del contenido polínico a lo largo del perfil muestran variaciones de los parámetros ambientales durante el Holoceno, en relación con el cambio de estepa a bosque. Se demuestra que en el centro de la Isla entre ca 6,800 y 7,775±205 años AP hubo una estepa de gramíneas, que se transformó en un bosque abierto entre 2,340±35 y 2,755±45 años AP, y a partir de 1,725±35 años AP se desarrolló el bosque cerrado, presente en la actualidad. Se supone que estas variaciones se relacionan con el aumento en la precipitación. Las asincronías en el establecimiento del bosque en otros sitios de Tierra del Fuego se deben al gradiente de humedad de los vientos del sureste.

scholarly journals El bosque como fuente de combustible: análisis antracológico de los sitios de la faja central de la Isla Grande de Tierra del Fuego

2020 ◽  
pp. 335-350
Author(s):  
Anna Franch Bach ◽  
M. Estela Mansur ◽  
Vanessa Parmigiani ◽  
Hernán H. De Angelis ◽  
M. Celina Alvarez Soncini ◽  
...  
Keyword(s):  
Tierra Del Fuego ◽  
Nothofagus Pumilio ◽  
Los Grupos

El objetivo de este trabajo es presentar el análisis antracológico de dos sitios de la faja central de la Isla Grande de Tierra del Fuego (Cabo San Pablo 2017 y Kami 7) y discutir la utilización de recursos leñosos por parte de los grupos que habitaron el área durante el Holoceno tardío. Se aplicó una metodología de análisis antracológico estándar, que incluyó la identificación taxonómica, la evaluación de alteraciones en la estructura de los carbones y estimación del calibre original de los leños utilizados. Los resultados demuestran un énfasis en el uso combustible de taxa de la clase fitosociológica Nothofagetea pumilionis-antarcticae, siendo Nothofagus pumilio y N. antartica/betuloides los más abundantes. Se registra una preponderancia de carbones de grandes calibres, de madera colectada en buen estado y alteraciones que reflejan eventos de altas temperaturas de fogón. De los resultados se deduce un aprovechamiento intenso y variado de los bosques cercanos a los sitios.

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