scholarly journals Neighbourhood and stand structure affect stemflow generation in a heterogeneous deciduous temperate forest

2019 ◽  
Vol 23 (11) ◽  
pp. 4433-4452 ◽  
Author(s):  
Johanna C. Metzger ◽  
Jens Schumacher ◽  
Markus Lange ◽  
Anke Hildebrandt

Abstract. Although stemflow oftentimes only represents a small portion of net precipitation in forests, it creates hot spots of water input that can affect subsurface storm-flow dynamics. The distribution of stemflow over different trees is assumed to be temporally stable, yet often unknown. Therefore, it is essential to know the systematic factors driving stemflow patterns. Several drivers have been identified in the past, mainly related to tree traits. However, less attention has been paid to tree neighbourhood interactions impacting stemflow generation and creating stand patches with enhanced or reduced stemflow. We recorded stemflow during 26 precipitation events on 65 trees, growing in 11 subplots (100 m2 each), in a temperate mixed beech forest in the Hainich National Park, Germany. We used linear mixed effects models to investigate how traits of individual trees (tree size, tree species, number of neighbouring trees, their basal area and their relative height) affect stemflow and how stemflow is affected by stand properties (stand, biomass and diversity metrics). As expected, stemflow increased with event and tree size. Stemflow was highly variable at both the tree and subplot scale. Especially in large rainfall events (>10 mm), the tree/subplot ranking was almost identical between events, probably due to fully developed flow paths bringing out the full stemflow potential of each tree. Neighbourhood and stand structure were increasingly important with event size (15 % of fixed effects on the tree scale and ca. 65 % on the subplot scale for large events). Subplot-scale stemflow was especially enhanced by a higher proportion of woody surface, expressed by a high number of trees, low leaf area and a large maximum tree size. The Simpson diversity index contributed positively to stemflow yield for large events, probably by allowing more efficient space occupation. Furthermore, our models suggest that the neighbourhood impacts individual tree morphology, which may additionally increase stemflow in dense, species diverse neighbourhoods. Unexpectedly, rain shading within the canopy had little impact on the stemflow spatial variation. Overall, we find a strong cross-scale temporal stability. Tree size and tree density were the main drivers, independently increasing stemflow, creating forest patches with strongly enhanced or reduced stemflow. Our results show that, besides tree metrics, forest structure and tree diversity also affect stemflow patterns and the potentially associated biogeochemical hot spots.

2019 ◽  
Author(s):  
Johanna C. Metzger ◽  
Jens Schumacher ◽  
Markus Lange ◽  
Anke Hildebrandt

Abstract. Although stemflow oftentimes represents only a small portion of net precipitation in forests, it creates hot spots of water input that can affect subsurface stormflow dynamics. The distribution of stemflow over different trees is assumed to be temporally stable, yet often unknown. Therefore, it is essential to know the systematic factors driving stemflow patterns. Several drivers have been identified in the past, mainly related to tree traits. Less attention has yet been paid to tree neighbourhood interactions impacting stemflow generation and creating stand patches with enhanced or reduced stemflow. We recorded stemflow in 26 precipitation events on 65 trees, growing in 11 subplots (100 m² each), in a temperate mixed beech forest in the Hainich National Park, Germany. We used linear mixed effects models to investigate how traits of individual trees (tree size, tree species, number of neighbouring trees, their basal area, and their relative height) affect stemflow and how stemflow is affected by stand properties (stand, biomass and diversity metrics). As expected, stemflow increased with event and tree size. Stemflow was highly variable at both tree and subplot scale. Especially in large rainfall events (> 10 mm), tree/subplot ranking was almost identical between events, probably due to fully developed flow paths bringing out the full stemflow potential for each tree. Neighbourhood and stand structure were increasingly important with event size (15 % of fixed effects on the tree scale, ca. 65 % on the subplot scale for large events). Subplot scale stemflow was especially enhanced by a higher proportion of woody surface, expressed by a high number of trees, low leaf area and a large maximum tree size. Simpson’s diversity index contributed positively to stemflow yield in large events, probably by allowing more efficient space occupation. Also, our models suggest that neighbourhood impacts individual tree morphology, which may additionally increase stemflow in dense, species diverse neighbourhoods. Unexpectedly, rain shading within the canopy had little impact on stemflow spatial variation. Overall, we find a strong cross-scale temporal stability. Tree size and tree density were the main drivers, independently increasing stemflow, creating forest patches with strongly enhanced or reduced stemflow. Our results show that, besides tree metrics, also forest structure and potentially diversity affect stemflow patterns and associated potentially biogeochemical hotspots.


1973 ◽  
Vol 3 (4) ◽  
pp. 495-500 ◽  
Author(s):  
James A. Moore ◽  
Carl A. Budelsky ◽  
Richard C. Schlesinger

A new competition index, modified Area Potentially Available (APA), was tested in a complex unevenaged stand composed of 19 different hardwood species. APA considers tree size, spatial distribution, and distance relationships in quantifying intertree competition and exhibits a strong correlation with individual tree basal area growth. The most important characteristic of APA is its potential for evaluating silvicultural practices.


1989 ◽  
Vol 13 (2) ◽  
pp. 76-80 ◽  
Author(s):  
Robert L. Bailey ◽  
Thomas M. Burgan ◽  
Eric J. Jokela

Abstract Data from 263 plots in a regional fertilization study of midrotation-aged slash pine plantations were used to fit prediction equations for basal area, trees per acre, stand average dominant height, diameter distributions, and individual tree heights. The equations include N and P fertilizationrates and CRIFF soil groups as predictor variables. The survival model also accounts for the accelerating effect of fusiform rust on mortality rate. Using published tree volume equations, the prediction of volumes by dbh class for fertilized slash pine plantations is now possible. This integratedsystem of equations is available as a user-friendly computer program that can calculate expected yields by diameter class and aid the forester in evaluating investment opportunities that include forest fertilization. South. J. Appl. For. 13(2):76-80.


2003 ◽  
Vol 33 (9) ◽  
pp. 1719-1726 ◽  
Author(s):  
C W Woodall ◽  
C E Fiedler ◽  
K S Milner

Intertree competition indices and effects were examined in 14 uneven-aged ponderosa pine (Pinus ponderosa var. scopulorum Engelm.) stands in eastern Montana. Location, height, diameter at breast height (DBH), basal area increment, crown ratio, and sapwood area were determined for each tree (DBH >3.8 cm) on one stem-mapped plot (0.2-0.4 ha) in each sample stand. Based on tree locations, various competition indices were derived for each sample tree and correlated with its growth efficiency by diameter class. In addition, trends in individual tree attributes by diameter class and level of surrounding competition were determined. For trees with a DBH <10 cm, growth efficiency was most strongly correlated with the sum of surrounding tree heights within 10.6 m. The index most highly correlated for larger trees was the sum of surrounding basal area within 6.1 m. Regardless of tree size, individual tree growth efficiency, basal area increment, and crown ratio all decreased under increasing levels of competition, with the effect more pronounced in smaller trees. These results suggest that individual trees in uneven-aged stands experience competition from differing sources at varying scales based on their size, with response to competition diminishing as tree size increases.


2011 ◽  
Vol 41 (3) ◽  
pp. 583-598 ◽  
Author(s):  
Jussi Peuhkurinen ◽  
Lauri Mehtätalo ◽  
Matti Maltamo

Airborne laser scanning based forest inventories employ two major methods: individual tree detection (ITD) and the area-based statistical approach (ABSA). ITD is based on the assumption that trees are of a certain form and can be delineated using airborne laser scanning techniques, whereas ABSA is an empirical method based on the relations between area-level forest attributes and laser echo height distributions. These two methods are compared here within the same test area in terms of their usefulness for estimating mean forest stand characteristics and tree size distributions. All evaluations were performed using leave-one-out cross validation. The average errors in volume and basal area did not differ significantly between the methods. ABSA resulted in overall better accuracies when estimating the diameter and height of the basal area median tree and the number of stems, whereas ITD produced significantly biased estimates for the number of stems and the mean tree size. Tree size distributions were estimated with slightly better accuracy using ABSA. More comprehensive investigations revealed that both methods were not able to estimate forest structure (tree size distribution and spatial distribution of tree locations), which in turn, affected the estimation accuracies.


1985 ◽  
Vol 2 (4) ◽  
pp. 117-120 ◽  
Author(s):  
Neil I. Lamson ◽  
H. Clay Smith ◽  
Gary W. Miller

Abstract Four West Virginia hardwood stands, managed using individual-tree selection for the past 30 years, were examined after the third and, in one instance, the fourth periodic harvest to determine the severity of logging damage. On existing skid roads, trees were removed with a rubber-tired skidder or a crawler tractor with a rubber-tired arch. Logging damage reduced residual stand basal area by 6%, a total of 6.1 ft² per acre. Damage was concentrated in the saplings—85% of the stems lost to logging damage were less than 5.0 in dbh. An adequate number of undamaged stems in all diameter classes remained after logging to achieve individual-tree selection stand structure goals. North. J. Appl. For. 2:117-120, Dec. 1985.


1988 ◽  
Vol 18 (7) ◽  
pp. 859-866 ◽  
Author(s):  
K. L. O'Hara

The growth of individual trees from four thinning treatments in a 64-year-old Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) stand was analyzed to determine desirable residual stand structures after thinning. Dominant and codominant trees had the highest individual tree stem volume growth rates over the previous 5 years, and accounted for most stand volume growth in thinned and unthinned stands. Two measures of growing space, crown projection area and sapwood basal area (a surrogate for leaf area), were used to measure how efficiently individual trees used their growing space. Crown classes were useful in characterizing growing space efficiency (volume growth per unit of growing space) only in the unthinned treatment. In thinned treatments, tall trees with medium-sized crowns were most efficient, while in the unthinned treatment, tall trees with relatively large crowns were most efficient. A large crown in an unthinned stand was comparable in size to a medium-sized crown in a thinned stand. Results suggest growing space is not limiting individual tree growth in thinned stands and that thinning to a particular stand structure is more appropriate than thinning to a particular level of stand density.


2016 ◽  
Vol 25 (2) ◽  
pp. e057 ◽  
Author(s):  
Irantzu Primicia ◽  
Rubén Artázcoz ◽  
Juan-Bosco Imbert ◽  
Fernando Puertas ◽  
María-del-Carmen Traver ◽  
...  

Aim of the study: We analysed the effects of thinning intensity and canopy type on Scots pine growth and stand dynamics in a mixed Scots pine-beech forest. Area of the study: Western Pyrenees. Material and methods: Three thinning intensities were applied in 1999 (0, 20 and 30% basal area removed) and 2009 (0, 20 and 40%) on 9 plots. Within each plot, pure pine and mixed pine-beech patches are distinguished. All pine trees were inventoried in 1999, 2009 and 2014. The effects of treatments on the tree and stand structure variables (density, basal area, stand and tree volume), on the periodic annual increment in basal area and stand and tree volume, and on mortality rates, were analysed using linear mixed effects models. Main Results: The enhancement of tree growth was mainly noticeable after the second thinning. Growth rates following thinning were similar or higher in the moderate than in the severe thinning. Periodic stand volume annual increments were higher in the thinned than in the unthinned plots, but no differences were observed between the thinned treatments. We observed an increase in the differences of the Tree volume annual increment between canopy types (mixed < pure) over time in the unthinned plots, as beech crowns developed. Research highlights: Moderate thinning is suggested as an appropriate forest practice at early pine age in these mixed forests, since it produced higher tree growth rates than the severe thinning and it counteracted the negative effect of beech on pine growth observed in the unthinned plots.Keywords: competition; Fagus sylvatica L.; Pinus sylvestris L.; forest management; mortality; Mediterranean forest.


2019 ◽  
Vol 3 (1) ◽  
pp. 10-19 ◽  
Author(s):  
MD. RAYHANUR RAHMAN ◽  
Md. MIZANUR RAHMAN ◽  
Md. ARIF CHOWDHURY ◽  
JARIN AKHTER

Abstract. Rahman MdR, Rahman MdM, Chowdhury MdA, Akhter J. 2019. Tree species diversity and structural composition: The case of Durgapur Hill Forest, Netrokona, Bangladesh. Asian J For 3: 10-19. Tree species diversity and stand structure of Durgapur hill forest were assessed through stratified random sampling method using sample plots of 20 m x 20 m in size during the period of October 2017 to May 2018. A total of 1436 stems of ≥5 cm DBH of 56 tree species belonging to 50 genera and 29 families were enumerated from sample area. Density (855 stem ha-1) and Basal area (29.27 m2 ha-1) of tree species were enumerated. Besides, Shannon-Wiener’s, Margalef’s, Simpson’s and Pielou’s diversity index were recorded for all the tree species. The study showed that the most dominant 10 species have 58% of the total IVI (174.29 out of 300). Where, Acacia auriculiformis showed the maximum Importance Value Index (51.02) followed by Shorea robusta (24.23). Number of individual tree species were highest (49) in the height range of 7- <12 m whereas maximum (52) species were recorded in the DBH (cm) range of 5- <10 cm. However, Acacia auriculiformis, Shorea robusta, and Tectona grandis were found as the most dominant species based on hierarchical cluster analysis. Therefore, current study will be helpful to the future policymakers in formulating forest resource management plan of Durgapur hill forest.


1996 ◽  
Vol 26 (10) ◽  
pp. 1838-1848 ◽  
Author(s):  
P. Lejeune

A model predicting circumference growth of individual trees has been developed for mixed irregular stands dominated by Fagussilvatica L. in southeastern Belgium. This model integrates simultaneously tree, stand, and growing site characteristics without considering distances between individual trees. It has a determination coefficient of 40.1% and a residual standard deviation of 0.45 cm/year. Forest mensuration variables considered in the model are circumference, tree social position represented by the total basal area of trees greater than the subject tree, stand basal area, and some index of stand structure corresponding to the ratio of the variance over the mean circumference. The site component is essentially expressed by the length of the growing period. The low accuracy obtained for individual tree growth is relative because the results are used mainly after individual trees have been distributed into size classes. We have been able to show that the introduction of crown description in the model can increase its accuracy. But this modification requires a submodel describing crown changes over time.


Sign in / Sign up

Export Citation Format

Share Document