Determination of the optimum felling frequency and sprout density in mid-term white poplar (Populus alba L.) cultivations (case study: Dehcheshme village in Farsan county)

Background and Objectives: The growing population and increasing demand for wood have led to the depletion of forest resources and a reduction in arable land.Poplars are known as one of the fastest-growing tree species and serve as a primary source of timber in the northern hemisphere.Various poplar species have been cultivated throughout Europe and the Middle East for the production of short-rotation coppice (timber crops) and medium-rotation coppice.After identifying suitable species, it is crucial for poplar growers to determine the optimal spacing for planting seedlings and the frequency of felling to ensure the growth of larger trees.This study investigates the effects of different planting densities and felling frequencies on the productivity of white poplar (Populus alba L.) plantations. Materials and Methods:This study was conducted in the poplar-growing region east of Deh Cheshmeh Village in Chaharmahal and Bakhtiari Province.It utilized a roughly 5-hectare field divided into 12 equally sized and leveled plots.These plots were classified into two categories: those with young trees (6 to 7 years old) and those with mature trees (15 to 18 years old).Researchers further divided the plots based on the number of past fellings (zero, one, or two) and tree density (low or high).Data on breast height diameter, total height, crown height, crown coverage, and standing volume were collected from 25-square-meter sample areas within each plot.The study employed a completely randomized block design with two factors: felling frequency and planting density.Results: Analysis of variance within the randomized block design, using tree age as a blocking factor, indicated that trees grown in plots subjected to a single past felling exhibited significantly larger breast height diameter, total height, crown coverage, and standing volume compared to those without prior felling or those that were pruned twice.Trees with two past fellings displayed the highest sprout count, while trees that were felled twice or not at all showed the highest ratio of crown height to total height.Furthermore, the findings highlighted that white poplar trees in lower planting density plots exhibited notably larger dimensions and volume than those in high-density plots. Conclusion:In summary, optimal cultivation of white poplar trees in the poplar cultivation hub of Chaharmahal and Bakhtiari Province indicates that maintaining a plantation density of fewer than 100 trees per hectare, along with a single prior felling, is advisable.