Dynamics of the diameter distribution after selection cutting in uneven- and even-aged northern hardwood stands: a long-term evaluation

Abstract

Selection cutting is defined as a tool for uneven-aged silviculture. Dependence on diameter distribution by forestry practitioners for identifying stand conditions has led to misuse of selection-like cuttings in even-aged northern hardwood stands. Our study used several long-term data sets to investigate the temporal stability in numbers of trees per diameter class in uneven-aged northern hardwood stands treated with single-tree selection and in 45-year-old second-growth stands treated with selection-like cuttings. We analyzed data from New York, Michigan, and Wisconsin to determine changes through time in number of trees across 2.5 cm diameter classes, shifts in the shape and scale of the three-parameter Weibull function used to describe the diameter distributions, and dynamics of associated stand attributes. Findings showed that single-tree selection cutting created and sustained stable diameter distributions and uniformity of conditions through consecutive entries in uneven-aged stands. By contrast, these characteristics varied through time in the second-growth stands that had been treated with selection-like cuttings. Analysis also showed that the Weibull shape and scale parameters for stands under selection system migrated towards those of the recommended target diameter distribution in the uneven-aged stands. These parameters diverged from the target with repeated use of selection-like cuttings in the second-growth even-aged stands.

Evaluating diameter distribution series of small-leaved lime (Tilia cordata Mill.) in forest stands

“…Moreover, the simple two-parameter form of its distribution often gives better results compared to the three-parameter form [ 3 , 6 , 30 ]. In addition, the two-parameter Weibull function was used in a large number of related studies due to the high correlation of its parameters (γ and β) with the stand characteristics [ 13 , 17 , 18 ]. Therefore, its application is suitable for describing the d 1,3 distributions in this study.…”

“…The stand structure is analyzed in terms of different tree species [ 1 , 8 , 9 ], composition [ 10 – 12 ], average age [ 4 , 13 ], age structure [ 10 , 14 ], growth site conditions [ 3 , 15 ], density [ 4 ], factors that affect the tree number distribution by diameter class [ 3 , 6 , 16 ]. Bassil et al [ 17 ] studied the temporal stability of the number of trees by diameter classes in different-aged Northern hardwoods that are subject to logging [ 17 ]. Many publications are aimed at searching for models and evaluating their effectiveness in describing the d 1,3 distribution [ 1 , 3 , 18 ], including those subjected to thinning [ 13 ].…”

Smallholder Farmers' Local Practices Underpinning the Use of Agroforestry Technologies in Uganda's Mt. Elgon Region

“…Direct observations showed that even after harvesting the mature trees, the remaining ones are often overcrowded with varying sizes and ages, leaving little space for young trees to grow and resulting in etiolation and stuntedness. Studies have also shown that when trees are stunted early due to competition, they hardly regain vigour (Bassil et al, 2019;Sharma et al, 2016), which can significantly impact the quality and quantity of firewood and poles harvested. While it's associated with the benefit of continuously harvesting trees for home use and income, relay planting can negatively impact tree vigour and the quality of tree products.…”

Evaluation of estimation methods for fitting the three-parameter Weibull distribution to European beech forests

“…Tree diameter distribution is a key piece of information about forest stand structure (Pretzsch 2009) which forest managers use to evaluate recent forest management and make decisions about further silvicultural treatments (Burkhart & Tomé 2012, Bassil et al 2019. Tree diameter distribution is integrated into several individual-tree and stand growth models (Schütz & Rosset 2020, Pretzsch et al 2002, Hasenauer et al 2006, Sterba et al 1995.…”