Predicting individual-tree growth of central European tree species as a function of site, stand, management, nutrient, and climate effects

2017 ◽  
Vol 137 (1) ◽  
pp. 29-44 ◽  
Author(s):  
Brigitte Rohner ◽  
Peter Waldner ◽  
Heike Lischke ◽  
Marco Ferretti ◽  
Esther Thürig
2015 ◽  
Vol 166 (6) ◽  
pp. 389-398 ◽  
Author(s):  
Brigitte Rohner ◽  
Esther Thürig

Development of climate-dependent growth functions for the scenario model “Massimo” Tree growth is substantially influenced by climatic factors. In the face of climate change, climate effects should therefore be included in estimations of Switzerland's future forest productivity. In order to include climate effects in the growth functions of the “Massimo” model, which is typically applied to project forest resources in Switzerland, we statistically modelled climate effects on tree growth representatively for Switzerland by simultaneously considering further growth-influencing factors. First, we used tree ring data to evaluate how climate variables should be defined. This analyses showed that for modelling multi-year tree growth we should use averages of whole-year variables. Second, we fitted nonlinear mixed-effects models separately for the main tree species to individual-tree growth data from the Swiss National Forest Inventory. In these models, we combined climate variables defined according to the results of the tree ring study with various further variables that characterize sites, stands and individual trees. The quantified effects were generally plausible and explained convincingly the physiological differences between the species. The statistical growth models for the main tree species will now be included in the forest scenario model “Massimo”. This will allow for founded analyses of scenarios which assume changing climatic conditions.


2016 ◽  
Vol 54 (1) ◽  
pp. 71-79 ◽  
Author(s):  
Juliette Chamagne ◽  
Matteo Tanadini ◽  
David Frank ◽  
Radim Matula ◽  
C. E. Timothy Paine ◽  
...  

2018 ◽  
Vol 48 (11) ◽  
pp. 1292-1301 ◽  
Author(s):  
Christopher E. Looney ◽  
Anthony W. D’Amato ◽  
Shawn Fraver ◽  
Brian J. Palik ◽  
Lee E. Frelich

Gradient studies of wetland forests have inferred that competition from upland tree species confines waterlogging-tolerant tree species to hydric environments. Little is known, however, about competition effects on individual-tree growth along stress gradients in wetland forests. We investigated tree growth and competition in mixed-species stands representing a waterlogging stress gradient in Fraxinus nigra Marsh. (black ash) forests in Minnesota, USA. Using competition indices, we examined how F. nigra basal area increment (BAI) responded to competition along the gradient and whether competition was size-asymmetric (as for light) or size-symmetric (as for soil resources). We modeled spatial distributions of F. nigra and associated tree species to assess how variation in species mixtures influenced competition. We found that although F. nigra BAI did not significantly differ with variations in site moisture, the importance of competition decreased as waterlogging stress increased. Competition across the gradient was primarily size-asymmetric (for light). Variation in species mixtures along the gradient was an important influence on competition. Some segregation of tree species occurred at all but the most upland site, where waterlogging stress was lowest and evidence of competition was greatest, confirming that competition from upland tree species confines F. nigra and potentially other waterlogging-tolerant species to hydric environments.


2019 ◽  
Vol 65 (6) ◽  
pp. 784-795
Author(s):  
Jeffrey S Ward ◽  
Jessica Wikle

AbstractSix study areas were established in 80–125-year-old upland oak stands on average sites to compare stand and individual tree growth response following two active treatments (B-level thinning, crop tree) with an unmanaged control. Initial stocking of 104 percent was reduced to 62 percent and 60 percent on the B-level and crop-tree-management plots, respectively. Approximately 7,200 board feet per acre (International ¼) were harvested on the actively managed plots with upland oaks accounting for 81 percent of pre- and 86 percent of residual stand. Eleven-year diameter and volume growth of oak sawtimber trees was greater on actively managed plots. Growth response increased with degree of release and was maintained for the length of the study. Because of the increased individual tree growth of oaks in response to release, stand volume growth of oak sawtimber did not differ between treatments. In contrast to an 11-year decline of poletimber stocking on unmanaged plots, poletimber stocking increased on managed plots as diameter growth increased in response to partial release. This may increase difficulty of regenerating oak in the future. For those mature red oak stands where traditional regeneration prescriptions will not be implemented or will be delayed, commercial harvests can be conducted without compromising stand volume growth of oak.


1995 ◽  
Vol 25 (1) ◽  
pp. 69-80 ◽  
Author(s):  
P.W. West ◽  
G.H.R. Osier

The factors determining individual tree growth response are examined during the 4 years following thinning in experiments in even-aged, 8- or 12-year-old regrowth Eucalyptusregnans F. Muell. forest at two sites in southern Australia. At one site, a vigorous understorey dominated by a sedge developed after the thinning. At that site, light-use efficiency by the trees was unaffected by thinning and the aboveground biomass production by the trees in the thinned stand was substantially less than that in the unthinned stand. At the other site, little understorey developed, light-use efficiency by trees in the thinned stand was greater than that in the unthinned stand, and aboveground biomass production was unaffected by thinning even though the leaf weight of the thinned stand was far below that of the unthinned stand. Where the understorey developed, it was concluded that it competed successfully with the trees for water, thereby reducing production in the thinned stand when compared with the unthinned stand. The individual tree growth response that occurred in the thinned stand at that site appeared to be due soley to the extra light available to individual trees following the canopy opening. Where the understorey did not develop, it was concluded that individual tree growth response was due not only to the extra light available to individual trees but also to the increased availability of belowground resources, most probably soil water. Application of a pre-existing stand growth model suggested that at that site the tendency for increased growth resulting from extra water availability in the thinned stand was just balanced by decreased growth due to lower radiation absorption by the reduced canopy, so that net production was unaffected by thinning.


2001 ◽  
Vol 154 (1-2) ◽  
pp. 261-276 ◽  
Author(s):  
Julian C. Fox ◽  
Peter K. Ades ◽  
Huiquan Bi

1992 ◽  
Vol 22 (5) ◽  
pp. 660-666 ◽  
Author(s):  
Paul C. Van Deusen

A number of recent studies have shown reduced stand-level and individual-tree growth in natural loblolly pine (Pinustaeda L.) stands in the southeastern United States. This study uses increment cores from dominant and codominant trees to determine if individual-tree growth has changed from 1915 to 1985. The cores are grouped for comparison by first sorting on the basis of median stand age and then further sorting these groups of cores by individual-tree age. These trees experienced increasing basal area increments from the mid-1940s into the mid-1970s, after which growth rates returned to preincrease levels. These data support recent findings of growth reductions, but also indicate previously unreported growth increases preceding the growth decreases. These and supplemental permanent plot data suggest that stand dynamics is a viable hypothesis for explaining these growth trends.


Sign in / Sign up

Export Citation Format

Share Document