scholarly journals Importancia del sector forestal en la contabilidad de gases de efecto invernadero (GEI) del país.

2021 ◽  
Vol 27 (3) ◽  
pp. 35-47
Author(s):  
Yasna Rojas ◽  
Carlos Buchner ◽  
Marjorie Martin ◽  
Sabine Müller-Using ◽  
Carlos Bahamondez
Keyword(s):  
Pinus Radiata

El sector forestal a través del bosque nativo, las plantaciones y los productos de madera recolectada juega un rol muy importante en el país, contribuye a la mitigación del cambio climático y es el principal sumidero de carbono. En el año 2018, contribuyó al balance de gases de efecto invernadero disminuyendo en 57% las emisiones del país, con una absorción neta de -68.878,3 kt CO2 eq. Desde 1990 hasta 2018 el sector ha aumentado las absorciones de carbono, en directa relación con el aumento de la superficie de bosques (forestación) y la incorporación de bosque nativo bajo manejo. En el caso del bosque nativo, se observa que la mayor contribución proviene de los bosques de renovales y de las áreas de conservación, mientras que en las plantaciones, la especie Pinus radiata es la que domina con una mayor absorción dada la mayor superficie respecto a otras especies exóticas. Las emisiones de GEI se relacionan directamente con el aumento de las cosechas de trozas y el consumo de leña, mientras que los incendios juegan un rol fundamental en el incremento de emisiones en años puntuales y se observa un aumento de la frecuencia de estos en los últimos años. El sector forestal tiene un potencial para aumentar su capacidad de sumidero de carbono, sin embargo, es necesario considerar todas las variables que afectan las absorciones y las emisiones que afectan al sector.

Agroforestry in Eastern Otago: results from two long-term experiments

2000 ◽  
pp. 93-98
Author(s):  
G.G. Cossens ◽  
M.F. Hawke
Keyword(s):  
Soil Ph ◽  
Tree Growth ◽  
Pinus Radiata ◽  
Carrying Capacity ◽  
Livestock Grazing ◽  
Tree Age ◽  
Rapid Decline ◽  
Pasture Production ◽  
Clover Content ◽  
Pasture Yield

During the first 20 years of a Pinus radiata tree rotation, tree growth and pasture yield were assessed under a range of tree spacings at Invermay and Akatore, two coastal sites in Eastern Otago. Pasture yield in association with trees thinned to 100 stems per hectare (sph) was comparable to that from open pasture up to a tree age of 12 years. By the 19th year, however, pasture production declined to 63% of open pasture yield at Invermay and to 42% at Akatore. At 200 and 400 sph at Akatore, pasture yield was similar to that from open pasture at tree age 12 years but declined to 27% and 0% of open pasture yield respectively by year 20. At both Invermay and Akatore, the ryegrass and clover content of open pasture was relatively constant throughout the term of the trial. However, both the ryegrass and clover content of pasture beneath trees began to decline by tree age 12 years with a very rapid decline at Akatore in the number of pasture species at 200 sph by the 19th year. No pasture remained at 400 sph, after 19 years. Livestock carrying capacity with sheep on tree treatments at Invermay decreased from 100% of open pasture at year 6 to 60% by year 10. At Akatore, livestock carrying capacity averaged over the 20-year life of the trial was 4.1 stock units per hectare with a maximum of 8.1 stock units at a tree age of 8 years. Tree growth at both sites was similar, averaging between 1 and 1.1 m/year in height over 20 years, with trees at Invermay at 100 sph averaging 9% greater height and diameter growth than at Akatore. Increasing tree stocking from 100 to 200 to 400 sph at Akatore, resulted in increased tree height, but decreased diameter at breast height. A comparison of the East Otago trees with those in a similar trial at Tikitere (Rotorua) 900 km further north indicated that the southern trees were about 6 years later in their growth pattern by tree age 20 years. On both sites, soil pH tended to be lower in the presence of trees and was significantly lower than in open pasture by year 20. The results and comparisons with the Tikitere data suggest that, in an integrated agroforestry regime, there will be livestock grazing under the trees further into the tree rotation in Otago than in North Island sites. However, slower tree growth would result in a longer rotation time to harvest. Current recommendations to farmers are to plant trees on the less productive areas of the farm and adopt a tree stocking rate which fully utilises the site. Keywords: agroforestry, livestock, pasture, Pinus radiata, soil pH, tree stocking

Changes in cell wall components and hygroscopic properties of Pinus radiata caused by heat treatment

2021 ◽  
Author(s):  
Alberto García-Iruela ◽  
Luis García Esteban ◽  
Francisco García Fernández ◽  
Paloma de Palacios ◽  
Alejandro B. Rodriguez-Navarro ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Cell Wall ◽  
Pinus Radiata ◽  
Cell Wall Components ◽  
Hygroscopic Properties ◽  
Wall Components

scholarly journals Using GEDI lidar data and airborne laser scanning to assess height growth dynamics in fast-growing species: a showcase in Spain

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Juan Guerra-Hernández ◽  
Adrián Pascual
Keyword(s):  
Pinus Radiata ◽  
Pinus Pinaster ◽  
Laser Scanning ◽  
Forest Ecosystems ◽  
Height Growth ◽  
Growth Patterns ◽  
Forest Growth ◽  
Airborne Laser Scanning ◽  
Fast Growing ◽  
Airborne Laser

Abstract Background The NASA’s Global Ecosystem Dynamics Investigation (GEDI) satellite mission aims at scanning forest ecosystems on a multi-temporal short-rotation basis. The GEDI data can validate and update statistics from nationwide airborne laser scanning (ALS). We present a case in the Northwest of Spain using GEDI statistics and nationwide ALS surveys to estimate forest dynamics in three fast-growing forest ecosystems comprising 211,346 ha. The objectives were: i) to analyze the potential of GEDI to detect disturbances, ii) to investigate uncertainty source regarding non-positive height increments from the 2015–2017 ALS data to the 2019 GEDI laser shots and iii) to estimate height growth using polygons from the Forest Map of Spain (FMS). A set of 258 National Forest Inventory plots were used to validate the observed height dynamics. Results The spatio-temporal assessment from ALS surveying to GEDI scanning allowed the large-scale detection of harvests. The mean annual height growths were 0.79 (SD = 0.63), 0.60 (SD = 0.42) and 0.94 (SD = 0.75) m for Pinus pinaster, Pinus radiata and Eucalyptus spp., respectively. The median annual values from the ALS-GEDI positive increments were close to NFI-based growth values computed for Pinus pinaster and Pinus radiata, respectively. The effect of edge border, spatial co-registration of GEDI shots and the influence of forest cover in the observed dynamics were important factors to considering when processing ALS data and GEDI shots. Discussion The use of GEDI laser data provides valuable insights for forest industry operations especially when accounting for fast changes. However, errors derived from positioning, ground finder and canopy structure can introduce uncertainty to understand the detected growth patterns as documented in this study. The analysis of forest growth using ALS and GEDI would benefit from the generalization of common rules and data processing schemes as the GEDI mission is increasingly being utilized in the forest remote sensing community.

Accuracy and Usefulness of Psychrometer and Pressure Chamber for Evaluating Water Potentials of Pinus radiata Needles

1982 ◽  
Vol 9 (5) ◽  
pp. 499 ◽  
Author(s):  
BD Millar
Keyword(s):  
Water Potential ◽  
Pinus Radiata ◽  
Xylem Sap ◽  
Pressure Chamber ◽  
Pressure Potential ◽  
Pine Trees ◽  
Average Water ◽  
Potential Gradients ◽  
Fundamental Uncertainty ◽  
The One

Pressure chamber evaluations of xylem sap pressure potential (P) and thermocouple psychrometric evaluations of average water potential (Ψl) in needles from both transpiring and non-transpiring pine trees (Pinus radiata D. Don) were compared in order to determine the relative accuracy and usefulness of these methods for assessing Ψl. Markedly different but linear P v. Ψl relationships were obtained for pine needles of different age and also for the case where resin exudation masked the xylem and led to a 'resin error'. Evidence suggests that these differences are mainly due to injection and resin errors in pressure chamber determinations totalling as much as 1 MPa (a 10 bar). The psychrometric method appears to be the much more accurate. Radial water potential gradients across leaves did not result in differences between evaluations of P and Ψl, at least in P. radiata. The need for multiple 'calibrations' of the pressure chamber and the fundamental uncertainty about the constancy of such calibrations on the one hand and the slowness of the excised-needle psychrometer on the other can restrict the usefulness of these methods.

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