Alternative silvicultural practices with variable retention to improve understory plant diversity conservation in southern Patagonian forests

Understory plants could can act as indicators of temperate forest sustainability, health and conservation status due to their importance in ecosystem function. Harvesting impacts on understory plant diversity depends on their intensity. Variable retention has been proposed to mitigate the harmful ef...

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Autores principales: Lencinas, María Vanessa, Martínez Pastur, Guillermo José, Gallo, Emilce, Cellini, Juan Manuel
Formato: Articulo
Lenguaje:Inglés
Publicado: 2011
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Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/151165
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spelling I19-R120-10915-1511652023-04-05T20:05:58Z http://sedici.unlp.edu.ar/handle/10915/151165 issn:0378-1127 issn:1872-7042 Alternative silvicultural practices with variable retention to improve understory plant diversity conservation in southern Patagonian forests Lencinas, María Vanessa Martínez Pastur, Guillermo José Gallo, Emilce Cellini, Juan Manuel 2011 2023-04-05T17:06:01Z en Ciencias Agrarias Aggregated retention Dispersed retention Biodiversity conservation Plant diversity Understory plants could can act as indicators of temperate forest sustainability, health and conservation status due to their importance in ecosystem function. Harvesting impacts on understory plant diversity depends on their intensity. Variable retention has been proposed to mitigate the harmful effects of timber harvesting, but its effectiveness remains unknown in southern Patagonian Nothofagus pumilio forests. The objectives of this study were to: (i) define a baseline of understory plant diversity in old-growth forests along a site quality gradient and under canopy gaps; (ii) evaluate stands with three different variable retention treatments compared to old-growth forests; and (iii) assess temporal changes during 4 years after harvesting (YAH). A 61 ha N. pumilio forest was selected. Understory plant (Dicotyledonae, Monocotyledonae and Pteridophyta) richness, cover (including woody debris and bare forest floor) and aboveground dry biomass were characterized in summer for 5 years. Before harvesting, baseline samples were conducted along a site quality gradient and outside/inside canopy gaps. Analyzed treatments include a control of old-growth forest (OGF) and three different harvesting treatments with variable retention: (i) dispersed retention (DR) of 30 m2 ha 1 (20–30% retention); (ii) aggregated retention (AR) with one aggregate per hectare and clear-cuts (28% retention); and (iii) combined dispersed and aggregated retention (DAR) with one aggregate per hectare and dispersed retention of 10–15 m2 ha 1 (40–50% retention). Data analyses included parametric and permutational ANOVAs, multivariate classification and ordinations. Before harvesting, 31 plant species were found, where richness, cover and biomass were directly related to site quality. The presence of canopy gaps did not have a significant impact on the measured variables. After harvesting, 20 new species appeared from adjacent associated environments (two from N. antarctica forests and 18 from grasslands and peatlands). At the stand level, understory values were higher in AR > DR > DAR > OGF. Most (81–95%) plant richness at baseline conditions was conserved in all treatments, where inside the aggregates understory remained similar to OGF. Combination of aggregated and dispersed retention (DAR) better limited exotic species introduction and protected sensitive species, improving conservation in harvested stands. Changes in understory variables were observed after the first YAH in all treatments; greater changes were observed in the harvested areas than in aggregates. Changes stabilized at the fourth YAH. As a conclusion, the location of retention aggregates should be selected to preserve species understory diversity of more speciose and diverse habitats or particularly uncommon stands. Implementation of different kinds (patterns and levels) of retention for improvement of biodiversity conservation in harvested forests should be included in timber and forest management planning. Facultad de Ciencias Agrarias y Forestales Articulo Articulo http://creativecommons.org/licenses/by-nc-sa/4.0/ Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0) application/pdf 1236-1250
institution Universidad Nacional de La Plata
institution_str I-19
repository_str R-120
collection SEDICI (UNLP)
language Inglés
topic Ciencias Agrarias
Aggregated retention
Dispersed retention
Biodiversity conservation
Plant diversity
spellingShingle Ciencias Agrarias
Aggregated retention
Dispersed retention
Biodiversity conservation
Plant diversity
Lencinas, María Vanessa
Martínez Pastur, Guillermo José
Gallo, Emilce
Cellini, Juan Manuel
Alternative silvicultural practices with variable retention to improve understory plant diversity conservation in southern Patagonian forests
topic_facet Ciencias Agrarias
Aggregated retention
Dispersed retention
Biodiversity conservation
Plant diversity
description Understory plants could can act as indicators of temperate forest sustainability, health and conservation status due to their importance in ecosystem function. Harvesting impacts on understory plant diversity depends on their intensity. Variable retention has been proposed to mitigate the harmful effects of timber harvesting, but its effectiveness remains unknown in southern Patagonian Nothofagus pumilio forests. The objectives of this study were to: (i) define a baseline of understory plant diversity in old-growth forests along a site quality gradient and under canopy gaps; (ii) evaluate stands with three different variable retention treatments compared to old-growth forests; and (iii) assess temporal changes during 4 years after harvesting (YAH). A 61 ha N. pumilio forest was selected. Understory plant (Dicotyledonae, Monocotyledonae and Pteridophyta) richness, cover (including woody debris and bare forest floor) and aboveground dry biomass were characterized in summer for 5 years. Before harvesting, baseline samples were conducted along a site quality gradient and outside/inside canopy gaps. Analyzed treatments include a control of old-growth forest (OGF) and three different harvesting treatments with variable retention: (i) dispersed retention (DR) of 30 m2 ha 1 (20–30% retention); (ii) aggregated retention (AR) with one aggregate per hectare and clear-cuts (28% retention); and (iii) combined dispersed and aggregated retention (DAR) with one aggregate per hectare and dispersed retention of 10–15 m2 ha 1 (40–50% retention). Data analyses included parametric and permutational ANOVAs, multivariate classification and ordinations. Before harvesting, 31 plant species were found, where richness, cover and biomass were directly related to site quality. The presence of canopy gaps did not have a significant impact on the measured variables. After harvesting, 20 new species appeared from adjacent associated environments (two from N. antarctica forests and 18 from grasslands and peatlands). At the stand level, understory values were higher in AR > DR > DAR > OGF. Most (81–95%) plant richness at baseline conditions was conserved in all treatments, where inside the aggregates understory remained similar to OGF. Combination of aggregated and dispersed retention (DAR) better limited exotic species introduction and protected sensitive species, improving conservation in harvested stands. Changes in understory variables were observed after the first YAH in all treatments; greater changes were observed in the harvested areas than in aggregates. Changes stabilized at the fourth YAH. As a conclusion, the location of retention aggregates should be selected to preserve species understory diversity of more speciose and diverse habitats or particularly uncommon stands. Implementation of different kinds (patterns and levels) of retention for improvement of biodiversity conservation in harvested forests should be included in timber and forest management planning.
format Articulo
Articulo
author Lencinas, María Vanessa
Martínez Pastur, Guillermo José
Gallo, Emilce
Cellini, Juan Manuel
author_facet Lencinas, María Vanessa
Martínez Pastur, Guillermo José
Gallo, Emilce
Cellini, Juan Manuel
author_sort Lencinas, María Vanessa
title Alternative silvicultural practices with variable retention to improve understory plant diversity conservation in southern Patagonian forests
title_short Alternative silvicultural practices with variable retention to improve understory plant diversity conservation in southern Patagonian forests
title_full Alternative silvicultural practices with variable retention to improve understory plant diversity conservation in southern Patagonian forests
title_fullStr Alternative silvicultural practices with variable retention to improve understory plant diversity conservation in southern Patagonian forests
title_full_unstemmed Alternative silvicultural practices with variable retention to improve understory plant diversity conservation in southern Patagonian forests
title_sort alternative silvicultural practices with variable retention to improve understory plant diversity conservation in southern patagonian forests
publishDate 2011
url http://sedici.unlp.edu.ar/handle/10915/151165
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