Estimating Litter production amount and quality for Eldar pine and umbrella Elm trees in historic city of Yazd

Abstract

This study aimed to estimate the quantity and quality of litter produced by pine and elm trees in the green space of historic city of Yazd. Litterbags were used to collect the leaves during a year. For each species, amount of nitrogen, phosphorus, calcium, sulfur, carbon, magnesium, and potassium levels was measured monthly. The results showed that the annual mean weight of all components of litter was 4056.56 g for pine and 4106.67 g for elm trees. The greatest fall of pine needles was recorded in September. The highest fall of elm leaves was measured in November. The specific leaf area of ​​elm and pine was calculated to be 169.38 and 29.96 cm2/g, respectively. The leaf area index for pine and elm was 0.91 and 7.99, respectively. The results showed no statistically significant difference between pine and elm trees in the leaf amount and total litter. The crown area of ​​pine and elm trees, exhibited a direct effect on the amount of total litter produced. There was a significant difference between the two species in organic matter percentage, whereas there was no significant difference between them in the carbon, calcium, and magnesium content. Elm had a significantly lower C/N than pine. The specific leaf area of elm was higher than pine and it is better in this index. Although pines are evergreen, they produce a lot of litter during one year. Considering the planting spacing, which is usually 3×3 or 5×5 meters, the litter production is estimated to be 1.622 to 4.507 ton.ha− 1 for eldar pine and 1.642 to 4.562 ton.ha− 1 for umbrella elm trees respectively. Our results point out the need to revise the mixing ratio of conifers in plantations to reduce the litter collecting costs by Yazd municipality and increase the soil productivity.