scholarly journals Structure, quality, production, LAI and dendrochronology of 100 years old Austrian pine (Pinus nigra ARNOLD) stand 

2012 ◽  
Vol 51 (No. 2) ◽  
pp. 67-76
Author(s):  
F. Tokár ◽  
E. Krekulová
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Annual Ring ◽  
Forest Type ◽  
Ring Width ◽  
Basal Area ◽  
Pinus Nigra ◽  
Production Quality ◽  
Area Index ◽  
Annual Ring Width

The paper evaluates the growth, structure, production, quality, leaf area index and dendrochronology of 100 years old Austrian pine (Pinus nigra ARNOLD) monoculture situated in the forest type group Fageto-Quercetum in the locality Horné Lefantovce (Nitrianska Streda Forest District, Topoľčianky Forest Enterprise). Codominant trees, trees with stem of high quality, with medium-sized crown, medium dense and straight crown are the most abundant in the stand. The tree number in the stand is 1,024 trees/ha, basal area 51.75 m2/ha, growing stock 571.56 m3/ha, aboveground biomass stock 348.76 t/ha and leaf area index 21.85 ha/ha. Dendrochronological analyses examined the response in individual sample trees and minimum annual ring width was found in 1920, 1922, 1925, 1929, 1933, 1938, 1944, 1946, 1947, 1949, 1952, 1954, 1963, 1968, 1976, 1982, 1990, 1993, 1998, 2001. Marked maximum values of annual ring width in the years 1919, 1923, 1926, 1930, 1936, 1937, 1941, 1948, 1951, 1955, 1959, 1966, 1972, 1975, 1980, 1985, 1997 were found as a positive productive feature. Beginning in the year 1993, dry Austrian pine trees occurred in the stand as a result of the fungal infection by Sphaeropsis sapinea (Fr.) Dyko et Sutton.

scholarly journals Algorithm for assessing forest stand productivity index using leaf area index

2019 ◽  
Vol 16 (3) ◽  
pp. 1311
Author(s):  
Faid Abdul Manan ◽  
Muhammad Buce Saleh ◽  
I Nengah Surati Jaya ◽  
Uus Saepul Mukarom
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Basal Area ◽  
Forest Stand ◽  
Productivity Index ◽  
Estimation Model ◽  
Area Index ◽  
Study Objective ◽  
Stand Productivity ◽  
Variable Combination

This paper describes a development of an algorithm for assessing stand productivity by considering the stand variables. Forest stand productivity is one of the crucial information that required to establish the business plan for unit management at the beginning of forest planning activity. The main study objective is to find out the most significant and accurate variable combination to be used for assessing the forest stand productivity, as well as to develop productivity estimation model based on leaf area index. The study found the best stand variable combination in assessing stand productivity were density of poles (X2), volume of commercial tree having diameter at breast height (dbh) 20-40 cm (X16), basal area of commercial tree of dbh >40 cm (X20) with Kappa Accuracy of 90.56% for classifying into 5 stand productivity classes. It was recognized that the examined algorithm provides excellent accuracy of 100% when the stand productivity was classified into only 3 classes. The best model for assessing the stand productivity index with leaf area index is y = 0.6214x - 0.9928 with R2= 0.71, where y is productivity index and x is leaf area index.

scholarly journals DEPENDENCE OF PINUS SYLVESTRIS WOOD STRUCTURE AND PHYSICAL PROPERTIES ON GROWTH ENVIRONMENT CONDITIONS

2001 ◽  
Vol 1 ◽  
pp. 181
Author(s):  
Kaspars Šķēle ◽  
Dace Cīrule ◽  
Anda Alksne ◽  
Jurijs Hrols
Keyword(s):  
Physical Properties ◽  
Annual Ring ◽  
Forest Type ◽  
Ring Width ◽  
Wood Properties ◽  
Annual Ring Width ◽  
Pine Wood ◽  
Growth Environment ◽  
Earlywood Width ◽  
Parameter Values

The paper considers the variation o f annual ring parameters and physical properties of wood of the pine species prevailing in Latvia’s forests, depending on the forest type (bog-land, vacciniosa) and the growth region in Latvia (Vidzeme, Latgale). Wood samples were taken from the stem butt-end, the middle and 3 A o f the height, in its sapwood or core part. An average annual ring width, latewood and earlywood width in the year ring, the percentage of latewood in the annual ring, wood density in oven-dry state (0), tangential swelling (tg) and radial swelling (rad) o f wood, as well as volume swelling (v) and swelling anisotropy coefficient (k) o f wood were determined for the samples. A comparison of these data shows that, in the majority of cases, the indices for the wood of pines grown in vacciniose have higher values, which suggests the advantage of pine wood over the bog-land pine wood. In its turn, no unambiguous distinctions between the parameter values for pine wood o f Latgale and Vidzeme origin were found, although the pine wood of Vidzeme origin had a somewhat higher indices. It may be concluded that the greatest impact on the leading pine wood properties is caused by the forest types regarded herewith, and not the belonging o f the pine wood site to its different growth regions in Latvia.

scholarly journals A PROPOSED METHODOLOGY FOR THE CORRECTION OF THE LEAF AREA INDEX MEASURED WITH A CEPTOMETER FOR PINUS AND EUCALYPTUS FORESTS

2016 ◽  
Vol 40 (5) ◽  
pp. 845-854 ◽  
Author(s):  
Domingos Mendes Lopes ◽  
Nigel Walford ◽  
Helder Viana ◽  
Carlos Roberto Sette Junior
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Correction Factor ◽  
Basal Area ◽  
Allometric Equations ◽  
Nutrient Cycle ◽  
Area Index ◽  
Physiological Processes ◽  
The Difference ◽  
Non Destructive

ABSTRACT Leaf area index (LAI) is an important parameter controlling many biological and physiological processes associated with vegetation on the Earth's surface, such as photosynthesis, respiration, transpiration, carbon and nutrient cycle and rainfall interception. LAI can be measured indirectly by sunfleck ceptometers in an easy and non-destructive way but this practical methodology tends to underestimated when measured by these instruments. Trying to correct this underestimation, some previous studies heave proposed the multiplication of the observed LAI value by a constant correction factor. The assumption of this work is LAI obtained from the allometric equations are not so problematic and can be used as a reference LAI to develop a new methodology to correct the ceptometer one. This new methodology indicates that the bias (the difference between the ceptometer and the reference LAI) is estimated as a function of the basal area per unit ground area and that bias is summed to the measured value. This study has proved that while the measured Pinus LAI needs a correction, there is no need for that correction for the Eucalyptus LAI. However, even for this last specie the proposed methodology gives closer estimations to the real LAI values.

scholarly journals Spatial and seasonal variations of leaf area index (LAI) in subtropical secondary forests related to floristic composition and stand characters

2016 ◽  
Author(s):  
Wenjuan Zhu ◽  
Wenhua Xiang ◽  
Qiong Pan ◽  
Yelin Zeng ◽  
Shuai Ouyang ◽  
...  
Keyword(s):  
Spatial Heterogeneity ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Seasonal Variations ◽  
Basal Area ◽  
Floristic Composition ◽  
Controlling Factors ◽  
Forest Types ◽  
Area Index ◽  
Subtropical Forests

Abstract. Leaf area index (LAI) is an important parameter related to carbon, water and energy exchange between canopy and atmosphere, and is widely applied in the process models to simulate production and hydrological cycle in forest ecosystems. However, fine-scale spatial heterogeneity of LAI and its controlling factors have not been fully understood in Chinese subtropical forests. We used hemispherical photography to measure LAI values in three subtropical forests (i.e. Pinus massoniana – Lithocarpus glaber coniferous and evergreen broadleaved mixed forests, Choerospondias axillaris deciduous broadleaved forests, and L. glaber – Cyclobalanopsis glauca evergreen broadleaved forests) during period from April, 2014 to January, 2015. Spatial heterogeneity of LAI and its controlling factors were analysed by using geostatistics method the generalised additive models (GAMs), respectively. Our results showed that LAI values differed greatly in the three forests and their seasonal variations were consistent with plant phenology. LAI values exhibited strong spatial autocorrelation for three forests measured in January and for the L. glaber – C. glauca forest in April, July and October. Obvious patch distribution pattern of LAI values occurred in three forests during the non-growing period and this pattern gradually dwindled in the growing season. Stand basal area, crown coverage, crown width, proportion of deciduous species on basal area basis and forest types affected the spatial variations in LAI values in January, while species richness, crown coverage, stem number and forest types affected the spatial variations in LAI values in July. Floristic composition, spatial heterogeneity and seasonal variations should be considered for sampling strategy in indirect LAI measurement and application of LAI to simulate functional processes in subtropical forests.

scholarly journals Influence of phytotechnology on growth, production and leaf area index of black walnut (Juglans nigra L.) monocultures in Slovakia

2012 ◽  
Vol 51 (No. 5) ◽  
pp. 213-224
Author(s):  
F. Tokár ◽  
E. Krekulová
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Dry Matter ◽  
Basal Area ◽  
Black Walnut ◽  
Juglans Nigra ◽  
Total Production ◽  
Area Index ◽  
Growth Production ◽  
Crown Thinning

In the paper we evaluate the influence of crown thinning with positive selection, different intensity (moderate PRP III and heavy PRP IV) and 5-year frequency on development of growth, production, quality and leaf area index of black walnut (Juglans nigra L.) monocultures growing on the series of three permanent research plots (PRP) Sikenica (Levice Forest Enterprise, Levice Forest District) as observed in 1978&ndash;2003. The trends of development of mean stem, basal area, standing volume and aboveground dendromass (in dry matter) were mainly influenced by heavy crown thinning. The index of growth was as follows: basal area 169.01%, standing volume 262.12%, aboveground dendromass (in dry matter) 324.48%. At the age of 64 years the black walnut monocultures tended by heavy crown thinning had the following parameters: basal area 31.03 m<sup>2</sup>/ha, standing volume 463.88 m<sup>3</sup>/ha and aboveground dendromass 194.98 t/ha. Mean periodic increment reached the values: basal area 0.51 m<sup>2</sup>/ha/year, standing volume 11.48 m<sup>3</sup>/ha/year and dendromass 5.39 t/ha/year. The index of increment percent growth was: basal area + 31.75%, growing stock + 30.85% and dendromass + 0.79%, compared to the control. The total production was also significantly influenced by heavy thinning. At the stand age of 64 years the tended stands had the total basal area of 4.92 m<sup>2</sup>/ha, total volume production of 572.77 m<sup>3</sup>/ha and total weight production of 246.04 t/ha. The total mean increment of basal area is 0.67 m<sup>2</sup>/ha/year, of volume 8.95 m<sup>3</sup>/ha/year and of weight 3.84 t/ha/year, which is by 24.07%, 23.96% and 16.01% more than on the control plot. The leaf area index at the age of 64 years ranges from 6.54 ha/ha (PRP III) to 7.82 ha/ha (PRP V). Dendrochronological analyses revealed minimum widths of annual rings in the years 1952, 1961, 1968, 1971, 1975, 1981, 1983, 1985, 1993, 2000, maximum ones in 1951, 1957, 1959, 1967, 1974, 1979, 1982, 1984, 1989, 1999.

scholarly journals Spectral composition of shortwave radiation transmitted by forest canopies

Trees ◽  
2020 ◽  
Vol 34 (6) ◽  
pp. 1499-1506
Author(s):  
Aarne Hovi ◽  
Miina Rautiainen
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Near Infrared ◽  
Forest Type ◽  
Spectral Composition ◽  
Shortwave Radiation ◽  
Forest Canopies ◽  
Area Index ◽  
Infrared Transmittance ◽  
Shortwave Infrared

Abstract Key message Leaf area index and species composition influence red-to-near-infrared and red-to-shortwave-infrared transmittance ratios of boreal and temperate forest canopies. In this short communication paper, we present how the spectral composition of transmitted shortwave radiation (350–2200 nm) varies in boreal and temperate forests based on a detailed set of measurements conducted in Finland and Czechia. Our results show that within-stand variation in canopy transmittance is wavelength dependent, and is the largest for sparse forest stands. Increasing leaf area index (LAI) reduces the overall level of transmittance as well as red-to-near-infrared and red-to-shortwave-infrared transmittance ratios. Given the same LAI, these ratios are lower for broadleaved than for coniferous forests. These results demonstrate the importance of both LAI and forest type (broadleaved vs. coniferous) in determining light quality under forest canopies.

scholarly journals Leaf area index estimation of even-aged oak (Quercus petraea) forests using in situ stand dendrometric parameters

2021 ◽  
Author(s):  
Briere Maxime ◽  
Christophe Francois ◽  
Francois Lebourgeois ◽  
Ingrid Seynave ◽  
Francois Ningre ◽  
...  
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Basal Area ◽  
Quercus Petraea ◽  
Forest Stand ◽  
Stand Age ◽  
Estimation Errors ◽  
Data Set ◽  
Area Index ◽  
Net Productivity

The leaf area index (LAI) is a key characteristic of forest stand aboveground net productivity (ANP), and many methods have been developed to estimate the LAI. However, every method has flaws, e.g., methods may be destructive, require means or time and/or show intrinsic bias and estimation errors. A relationship using basal area (G) and stand age to estimate LAI was proposed by Sonohat et al. (2004). We used literature data in addition to data form measurements campaign made in the northern half of France to build a data set with large ranges of pedoclimatic conditions, stand age and measured LAI. We validated the Sonohat et al. (2004) relationship and attempted to improve or modify it using other stand/dendrometric characteristics that could be predictors of the LAI. The result is a series of three models using the G, age and/or quadratic mean diameter (Dg), and the models were able to estimate the LAI of an oak only even-aged forest stand with good confidence (root mean square error, RMSE < 0.75) While G is the main predictor here, age and Dg could be used conjointly or exclusively given the available data, with variable precision in the estimations. Although these models could not, by construction, relate to the interannual variability of the LAI, they may provide the theoretical LAI of an untouched forest (no meteorological, biotic or anthropogenic perturbation) in recent years. additionally, the use of this model may be more interesting than an LAI measurement campaign, depending on the means to be invested in such a campaign.

The role of stand density on growth efficiency, leaf area index, and resin flow in southwestern ponderosa pine forests

2007 ◽  
Vol 37 (2) ◽  
pp. 343-355 ◽  
Author(s):  
Nate G. McDowell ◽  
Henry D. Adams ◽  
John D. Bailey ◽  
Thomas E. Kolb
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Ponderosa Pine ◽  
Basal Area ◽  
Stand Density ◽  
Growth Efficiency ◽  
Resin Flow ◽  
Area Index ◽  
Sapwood Area ◽  
Ponderosa Pine Forests

We examined the response of growth efficiency (GE), leaf area index (LAI), and resin flow (RF) to stand density manipulations in ponderosa pine ( Pinus ponderosa Dougl. ex Laws.) forests of northern Arizona, USA. The study used a 40 year stand density experiment including seven replicated basal area (BA) treatments ranging from 7 to 45 m2·ha–1. Results were extended to the larger region using published and unpublished datasets on ponderosa pine RF. GE was quantified using basal area increment (BAI), stemwood production (NPPs), or volume increment (VI) per leaf area (Al) or sapwood area (As). GE per Al was positively correlated with BA, regardless of numerator (BAI/Al, NPPs/Al, and VI/Al; r2 = 0.84, 0.95, and 0.96, respectively). GE per As exhibited variable responses to BA. Understory LAI increased with decreasing BA; however, total (understory plus overstory) LAI was not correlated with BA, GE, or RF. Opposite of the original research on this subject, resin flow was negatively related to GE per Al because Al/As ratios decline with increasing BA. BAI, and to a lesser degree BA, predicted RF better than growth efficiency, suggesting that the simplest measurement with the fewest assumptions (BAI) is also the best approach for predicting RF.

Using heterogeneity indices to adjust basal area – Leaf area index relationship in managed coniferous stands

2020 ◽  
Vol 458 ◽  
pp. 117699
Author(s):  
Alex Appiah Mensah ◽  
Hans Petersson ◽  
Svetlana Saarela ◽  
Martin Goude ◽  
Emma Holmström
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Basal Area ◽  
Area Index

scholarly journals Forest Degradation Assessment Based on Trend Analysis of MODIS-Leaf Area Index: A Case Study in Mexico

2019 ◽  
Vol 11 (21) ◽  
pp. 2503 ◽  
Author(s):  
Reygadas ◽  
Jensen ◽  
Moisen
Keyword(s):  
Time Series ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Vegetation Index ◽  
Forest Type ◽  
Forest Degradation ◽  
Future Research ◽  
Type Model ◽  
Area Index ◽  
Trend Component

: Assessing forest degradation has been a challenging task due to the generally slow-changing nature of the process, which demands long periods of observation and high frequency of records. This research contributes to efforts aimed at detecting forest degradation by analyzing the trend component of the time series of Leaf Area Index (LAI) collected by the Moderate Resolution Imaging Spectroradiometer (MODIS) over Central Mexico from 2002 to 2017. The analysis of the trend component is proposed to overcome the challenge of identifying very subtle and gradual changes that can be undetected if only the raw time series is examined. Additionally, the use of LAI as an alternative to other widely used indexes (e.g., Normalize Difference Vegetation Index and Enhanced Vegetation Index) facilitates consideration of the structural changes evident from degradation though not necessarily observable with spectral indices. Overall, results indicate that 52% of the study area has experienced positive trends of vegetation change (i.e., increasing LAI), 37% has remained unchanged, and 11% exhibits some level of forest degradation. Particularly, the algorithm estimated that 0.6% (385 km2) is highly degraded, 5.3% (3406 km2) moderately degraded, and 5.1% (3245 km2) slightly degraded. Most of the moderate and highly degraded areas are distributed over the east side of the study area and evergreen broadleaf appears to be the most affected forest type. Model validation resulted an accuracy of 63%. Some actions to improve this accuracy are suggested, but also a different approach to validate this type of study is suggested as an area of opportunity for future research.

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