Quantitative and qualitative attributes of dead wood in dominated by Carpinus betulus L. forests in Kaniv Nature Reserve

The article presents the quantitative and qualitative attributes of dead wood in forests dominated by Carpinus betulus L. in Kaniv Nature Reserve. The study was conducted in 130–140-year natural common hornbeam forests on two permanent sample plots of 0.24 ha each by identifying and measuring all components of standing and lying (fallen) dead wood. It was found that wood detritus has an average volume of 39.8 m3/ha consists of standing dead trees (23.1%) and fallen dead wood (76.9%). The species composition is dominated by common hornbeam (96.5%), and the share of Norway maple (Acer platanoides L.) is low (3.5%). Wood of II (13.2 m3/ha, 33.1%) and III (12.2 m3/ha, 30.7%) classes of destruction predominates. Standing dead wood is formed by only one tree species — common hornbeam and has an average volume of 9.2 m3/ha. It is represented mainly by standing broken trees. The volume of standing dead wood is dominated by wood detritus of the II stage of decomposition (95.7%). Fallen dead wood is formed by two tree species — common hornbeam (95.4%) and Norway maple (4.6%), has an average volume of 30.6 m3/ha. It is represented by whole uprooted and broken fallen trees (trunks), fragments of fallen trees (trunks) and rough branches. Lying dead wood is represented by detritus of all five classes of decomposition, but wood of III (12.2 m3/ha, 39.9%) and IV (9.6 m3/ha, 31.4%) classes predominates. The volume of fallen dead wood is mainly formed by components with an average diameter of 10.1–30.0 cm (75.7%). The diversity of fractions and components, structural features, sizes and stages of decomposition of dead wood can be important in the formation of potential habitats and substrates for a number of species of living organisms.

Estimation of coarse woody debris stocks in forest ecosystems of Slobozhansky national nature park

Dead wood is an important component of forest ecosystems. It performs a number of environmental functions. Coarse woody debris includes standing dead trees, fallen dead trees, fragments of fallen trees (trunks), branches (fragments of branches), and rough tree roots. It is a substrate and habitat for living organisms, including a number of species of mosses, lichens, fungi, invertebrates, as well as birds and mammals. Woody detritus plays an important role in the biological cycle of substances and energy, and carbon deposition, is a source of nutrients. Therefore, the study of quantitative and qualitative features of dead wood, in particular on protected areas, is a considerable nowadays problem. The aim of the work is to estimate identified by forest inventory stocks of dead wood in forest ecosystems of Slobozhansky NNP by categories, as well as to analyze the distribution of its volumes in stands of dominant tree species and forest types. The estimation of coarse woody debris stocks was performed based on forest inventory data of Slobozhansky National Nature Park conducted by Ukrainian State Project Forestry Production association “Ukrderzhlisproekt”. Data from 493 forest stands of nine tree species were analyzed. The stock of the following fractions of coarse woody debris was studied: standing dead wood, fallen (downed) dead wood. Data analysis was performed using MS Excel 2016 software. It was found that the total area of forest stands in which standing or downed dead wood was found during forest inventory was 2149.8 ha, or 47.5% of the total forest area of NNP. The total stock of coarse woody debris was 19478 m3, more than 95% of which is concentrated in the stands of Scots pine (Pinus sylvestris L.) (78.8%) and pedunculate oak (Quercus robur L.) (16.6%). Standing dead wood prevailed (62.1%) fallen dead wood (37.9%) in the structure of dead wood volume. The volume of dead wood was in the range of 5–50 m3∙ha–1, and on average in studied forest ecosystems in which it was found was 9.1 m3∙ha–1. In Scots pine forest stands coarse woody debris was found on an area of 1703.5 hectares with total stock of 15355 m3, consists of standing dead trees (9952 m3, 64.8%) and fallen dead wood (5403 m3, 35.2%). The volume of dead wood in forest stands was 5–50 m3∙ha–1, on average – 9.0 m3∙ha–1. In pedunculate oak stands coarse wood debris was found on an area of 384.7 hectares with a total stock of 3224 m3, consists of standing dead wood (1469 m3, 45.6%) and fallen dead wood (1755 m3, 54.4%). The volume of dead wood in forest stands was 5–20 m3∙ha–1, on average – 8.4 m3∙ha–1.

WOODY NECROMASS STOCK IN MIXED OMBROPHILOUS FOREST USING DIFFERENT SAMPLING METHODS

ABSTRACT The objective of this study was to quantify the necromass stock in a Mixed Ombrophilous Forest (MOF) fragment in the National Forest of Irati, State of Paraná, Brazil. Two sampling methods were tested: FA1, consisting of a fixed area (FA) approach with sample units measuring 2,500 m2 (50 m × 50 m); and FA2, consisting of fixed area sampling units measuring 500 m2 (10 m × 50 m) and line intercept sampling (LI) using 50 m lines. Data were collected on permanent sample plots installed in the area, consisting of 25 square blocks of 1 ha. Fallen dead wood pieces with a diameter = 10 cm were used in the analysis. The dead wood was classified into three degrees of decomposition, and masses were calculated as the corresponding density at each class. The tested sampling methods were evaluated using coefficient of variation and relative sampling error, and the nonparametric Kruskal-Wallis test was used to compare the results between the methods. Volume size of fallen dead wood did not statistically differ between the methods, but variation in necromass volume was lower in the FA1 method, whereas the FA2 method had a smaller sampling error. Overall sampling error ranged from 23.4-27.92%; lowering the sampling error to 15% would require a high sampling intensity (FA1: 42 area units [a.u.], FA2: 99 a.u., and LI: 236 a.u.). Total necromass weights amounted to 4.67 Mg.ha-1 (FA1); 5.16 Mg.ha-1 (FA2) and 4.58 Mg.ha-1 (IL), and carbon stock estimates were 2.00 Mg.C.ha-1 (FA1); 2.20 Mg.C.ha-1 (FA2) and 1.96 Mg.C.ha-1 (IL).

Mass of downed wood in northern hardwood forests in New Hampshire: potential effects of forest management

Downed (i.e., fallen, dead) wood was sampled in 1-, 15-, 50-, and 100-year-old managed stands, an uneven-aged, managed stand, and an uncut stand of northern hardwoods in New Hampshire. Mass of downed wood ranged from a mean of 32 t/ha in the 15- and 50-year-old stands to 86 t/ha in the recently cut stand. Mean estimates varied significantly among stands, although most of the variation was due to the large amount of downed wood in the recently cut stand. The range of downed-stem diameters was greatest in the 100-year-old and uncut stands. Large (>38 cm) logs were notably absent from the uneven-aged, managed stand, indicating that selective cutting utilizes mature stems efficiently. Comparison of our data with other estimates shows that the amount of downed wood in northern hardwood stands declines to about 20 t/ha within 20–30 years after logging. Quantities remain relatively stable for up to an additional 30 years and then begin to increase. They stabilize at 35–40 t/ha after approximately 100 years. Large-diameter logs become an increasingly important component of downed wood as stands mature beyond 50 years of age. Rapid decomposition of even the largest logs precludes continued accumulation of downed wood in uncut, old-growth stands. The data suggest that less downed wood and fewer large-diameter logs are likely to accumulate under short-rotation (<50 years) harvest, whole-tree harvests, and selection cuts than under long rotations or in uncut forests.