Uprooted Trees Research Articles

Promoting Turf Recovery Following a Hurricane

Devastation from hurricanes can cause multiple problems for turfgrass managers, sod producers, and homeowners. Damage may include visible factors such as prolonged periods of standing water, uprooted trees, shading and obstruction from demolished structures, deposition of silt or mud, and damage to irrigation systems. Less visible problems may include damage to root systems resulting from compacted soil from heavy equipment used during cleanup and recovery, reduced drainage, and injury resulting from effects of saltwater intrusion. Suggested guidelines for correcting these problems are included in the text.

Mangrove tree strength estimated with field experiments

Mangrove forests protect coastal communities from wind and wave energy, including during extreme events such as cyclones and tsunamis. Under extreme conditions, energy absorption often exceeds mangrove tree strength, resulting in broken stems and uprooted trees. Such damage can restructure mangrove community composition and function for decades. Predicting the vulnerability of mangrove forests to damage from external forces is critical for understanding the likelihood of forest structural change during damaging events. Despite the importance of such predictions, we have little mechanistic understanding of mangrove tree strength. We measured mangrove strength across three root types (prop roots, pneumatophores, and buttress roots) using static pulling tests. We applied a non-destructive load to mangrove trees using a winch, and related the force applied to the bending induced in the tree. Mangroves were stronger than terrestrial trees, per unit tree size, and this scaled strength was similar across mangrove species of different root types. Un-scaled mangrove strength increased exponentially with tree size, towards a strength asymptote for the largest trees. Enhanced empirical knowledge of mangrove tree strength is critical to understand the coastal protection services provided by diverse mangrove forests, particularly in a future of global climate change and increased occurrence of extreme storms.

A Possible Meteoric Fall in Cabeza la Vaca (Spain) in 1970 January

We recover a report in the “HOY” regional newspaper about a presumed meteorite fall near Cabeza la Vaca, Spain. The report details observable effects like a crater, uprooted tree, and a destroyed fence. While the exact date is unknown, it likely occurred within a week of 1970 January 27. The report lacks the crater size specification. This research note underscores the potential significance of the reported meteorite fall, encouraging further investigation.

Floating marine debris influx in the intertidal zone of offshore islands in Bangladesh: A case study of Manpura Island

Marine Debris is all-pervading in the world's oceans. In this research, for the first time, Floating Marine Debris (FMD) accumulation in the intertidal zone of Manprua island, an offshore island of Bangladesh, is reported. The assessment has been done by integrating both physical investigations and questionnaire survey. The Study shows high debris density on the windward and river-facing sides of the island. The density of debris items in this area varies from 550,000 to 60,000 items per km2 (8.5 to 0.08 g/m2) for transect samples during low tide and 350,000 to 60,000 items per km2 (5.76 to 1.20 g/m2) for net samples during high tide. However, the most damaging debris items are uprooted trees and water hyacinths because they hinder fishing activities. This study provides baseline information on FMD in the Meghna Estuary, which can be used as a reference for sustainable monitoring and management of marine pollution.

Effects of root plates, pits and mounds following windthrow events on the biodiversity of plants and lichens in Central European mountain forests

Windthrows lead to the formation of a characteristic land microtopography and they provide new habitats and substrata for species. The present study is novel, because it concerns different taxonomic groups of organisms and effects of various variables on species composition, richness and abundance within root plate-pit-mound (RPM) complexes. For the first time we studied lichens, liverworts, mosses and vascular plants on RPM complexes across major vegetation types, from deciduous to coniferous forests. We analyzed 164 RPM complexes which included in total 268 components: 115 root plates, 80 pits and 73 mounds. Besides the vegetation types and component types the following variables were also considered: dimensions (area, size), age (decomposition degree), species of the uprooted tree, shade, and elevation. The research revealed that root plates, pits and mounds had their own indicator species, but the key factors for the species composition were the species of uprooted trees and the vegetation type. Furthermore, the type of component and the vegetation type were also the most main variables determining the richness and abundance of the studied taxonomic groups of species. Analyses revealed the greatest species richness and abundance of lichens on root plates, and the highest richness of liverworts and vascular plants in pits. The type of component had no effect on the species richness of mosses. However, they were most abundant on mounds. The response of individual groups to the vegetation types and other variables varied. Findings from the study indicated that the presence of uprooted trees with different features (size and age, species of uprooted tree) is important for the biodiversity of mountain forests. We recommend leaving uprooted trees in forest communities for natural colonization, preferably large objects. Moreover, in managed forests a mosaic of forest communities that mimic the structure of natural unmanaged forests should be supported.

Causes and consequences of large-scale windthrow on the development of fir-beech forests in the Dinaric mountains

We investigated several aspects of windthrow that are relevant to our understanding and management of forest ecosystems. As an example, we used an extreme event in December 2017, when the strongest storm in recent history occurred in the Slovenian Dinaric High Karst. We examined influential factors such as soil properties, wind speed, precipitation and ecological consequences for the affected forests. Soil properties were measured around standing and fallen silver fir trees at all three research sites. Tree species composition in the regeneration was observed on plots with chemical and acoustic ungulate deterrents and on control plots without deterrents. Economic estimates of yield loss due to damage were calculated at the national level. A model of the potential threat from windthrow was also developed based on data collected from windthrow events and meteorological data over the past 20 years. Our results indicate that soil depth and mineral fraction depth were similar at sites with and without damaged trees and were not the determining factors for tree toppling. Plots with acoustic deterrents showed the most effective regeneration development, the least decline in silver fir and the greatest increase in noble hardwood seedlings, while plots with chemical deterrents showed the least browsing damage. The estimated economic loss of €16.1 million is 6.6% less than the harvest under normal conditions. The economic loss was relatively low due to the nature of the storm, with the predominant type of damage being uprooted trees with no damaged trunks. The windthrow hazard model revealed that a large number of consecutive events with strong winds in each section weakened the stand, which was subsequently knocked down during the next extreme wind and rainfall event.

A 6-year study on the mortality dynamics of sprouts germinated on Schima superba after a severe ice storm in southern China.

Natural disturbances modify forest structure by affecting regeneration dynamics and can change main ecosystem functions. An ice storm unusually took place in southern China in early 2008, which caused huge damage to forests. Resprouting of woody plants in a subtropical forest has received little attention. The role of survival time and mortality has been assessed for newsprouts after an ice storm. In this study, damage types, in addition to the annual number and mortality rates of sprouts for all tagged and sampled resprouted Chinese gugertree (Schima superba Gardner & Champ.) individuals more than or equal to 4 cm in basal diameter (BD), were monitored. A total of six plots (20 m × 20 m) wererecorded in a subtropical secondary forest dominated by S. superba in Jianglang Mountain, China. This investigation had been conducted for six consecutive years. The results showed that the survival rates of the sprouts were dependent on the year they sprouted. The earlier the year they boomed, the lower the mortality. The sprouts produced in 2008 were of the highest vitality and survival rates. Sprouts of the decapitated trees exhibited a better survival rate than those of uprooted or leaning trees. Sprouting position also plays a role in regeneration. Sprouts at the basal trunks of uprooted trees and the sprouts at the upper trunksof the decapitated trees exhibited the lowest mortality. The relationship between the accumulative mortality rate and the average diameter of new sprouts isaffected by damage types. We reported the mortality dynamics of sproutsin a subtropical forest after a rare natural disaster. This information could serve asa reference for the construction of a branch sprout dynamic model ormanagement of forest restoration after ice storms.

UAV Inventory of the Last Remaining Dragon Tree Forest on Earth

The last remaining Dragon Tree Forest on Earth survives on a small plateau (Roqeb di Firmihin) in Socotra Island (Yemen). The Socotran Dragon’s Blood Tree (Dracaena cinnabari Balf. f.) is endemic to the Socotra Archipelago UNESCO World Heritage Site. Being a culturally important and endangered tree species, its conservation is a priority. Despite this, a complete inventory of the Firmihin Dracaena forest (14.9 km2) has never been attempted before. We applied the use of unmanned aerial vehicles (UAVs) for the first time in conserving the Socotran Dragon’s Blood Tree. A pair of UAVs (small drones) were used during field surveys in 2021 to spatially describe individual tree positions, tree density, mortality, and the forest age structure. Aerial images were processed into a single orthophoto image of high spatial resolution (8 cm/pixel) used for detailed analysis. We applied image-enhancement techniques, used object-based classification, and corrected every entry manually during the inventory process. In total 35,542 individual living trees and 2123 uprooted trees were inventoried. The mean age of the forest, based on crown age (derived from crown size) was estimated at an average of ca. 300 years (291.5 years) with some individuals older than 500 years. Our analysis reveals that the trajectory of recent cyclones and the average direction of fallen trees in Firmihin are correlated, suggesting that intensified winds (as a result of global warming) catalyze the decline of the overmature forest. Our study illustrates the use of UAVs in collecting crucial data for the conservation and threat assessment of endangered tree species in Socotra, and regular drone inventories could be applied (e.g., after future cyclone events or landslides) to better evaluate the status of these vulnerable island ecosystems.

Soil erosion affected by trees in a tropical primary rain forest, Papua New Guinea

Trees have the ability to distinctly determine soil evolution and hillslope processes through mechanical soil disturbances such as tree uprooting. Recent findings have resulted in new biogeomorphic state transition models for old-growth forests in the temperate climate zone. The situation in tropical forests, however, is mostly unknown. Here, we focus on determining short- (decades) and long-term (millennia) soil erosion rates and the biogeomorphic role of trees on hillslope dynamics in the species-rich Wanang primeval tropical forest, Papua New Guinea. We hypothesized that trees play a significant role in hillslope dynamics on a background of powerful soil erosion dominated by abiotic factors, and that this role has potentially intensified over the last decades.The long-term soil erosion was assessed using the meteoric 10Be levels in three soil profiles along the whole depth gradient along with one natural outcrop. The recent soil erosion rate was determined using 239+240Pu levels in the uppermost soil layers. The specific role of trees in hillslope processes was evaluated based on repeated tree censuses of 65,535 tree individuals, calculating the tree mortality rate and modeling the soil volume affected by uprooted trees and by the in situ decay of the root systems of broken trees.Soil erosion was 6.25 m3 ha−1 yr−1 over the long term and indeed did increase during the last decades. While this rate was significantly affected by trees, they were not the main factor, with circa 0.95 m3 ha−1 influenced annually by uprooting, and an additional 0.61 m3 ha−1 by the in situ decay of root systems. These results reflect a forest ecosystem that is currently in the biogeomorphic stage of biotic/abiotic feedbacks.

Корневая система тополя бальзамического (Populus balsamifera L.)

The research aims at studying the features of the balsam poplar root system in the conditions of Arkhangelsk. The relevance of the topic is determined by the poplar multifunctionality in urban conditions. The effectiveness of sanitation functions, phytoremediation, carbon sequestration, and sustainability of poplars is determined by their root system condition. Understanding the specifics of its structure will enable the selection and creation of conditions necessary for the successful growth of trees of this species. Studies of the root system structure, recording the number, diameter, and branching of roots of different orders were carried out on uprooted trees growing isolated as well as in groups. In public gardens, the length of poplar skeletal roots with their subsequent surface excavation was assessed using the Arbotom device with the Arboradix module. A strong foundation in the central part of the root system, formed of the overgrown core, buttress roots of the first order and fibrous roots, provides resistance of poplars to windthrow. The bending of first-order roots early in tree development creates a holding platform for the branch cuttings. The close group growth of poplars leads to “storeying” and deepening of the root system. Poplars growing in groups form a greater number of proximal roots with a smaller diameter compared to isolated growth. Thus, the average diameter of the base of the first-order roots in group growth is 11.5 cm; in single growth – 24.5 cm. The length of poplar skeletal roots in public gardens ranges from 2 to 9 m. Reducing the share of poplars in the plantation by 2.3 times together with a decrease in stand density by 2 times or track area by 2 times leads to an increase in the length of skeletal roots by 1.5–2 times and the formation of a more uniform root system. The results can be used in the design of urban green spaces. For citation: Tyukavina O.N., Popova L.F. Root System of Balsam Poplar (Populus balsamifera L.). Lesnoy Zhurnal = Russian Forestry Journal, 2022, no. 6, pp. 71–81. (In Russ.). https://doi.org/10.37482/0536-1036-2022-6-71-81

Beach erosion: Threat and adaptation measures of communities in the Tun Mustapha Park (TMP), Sabah, Malaysia

Beach erosion is among the main phenomena affecting small islands in the Coral Triangle region, particularly in the Tun Mustapha Park (TMP), Malaysia. This study was done to investigate the level of beach erosion and to determine the adaptation measures for the coastal communities to beach erosion. Field trips were carried out in May and July 2017 at seven islands (Banggi, Tiga, Balambangan, Malawali, Molleangan, Tigabu and Mandidarah) of TMP. Semi-structured interviews were conducted with 50 respondents who were the coastal inhabitants of the islands, to gain local knowledge about island beach erosion. Results indicate that beach erosion occurred during the peak of monsoon seasons and extreme events. Wind-induced high waves during the end of the year (northeast monsoon) eroded beaches, damaged houses, fishing structures and uprooted trees. Six of the islands are affected by beach erosion, whereas Mandarah island is experiencing accretion. Karakit beach is the only study site protected by seawall and beach revetment. The identified coastal adaptations to beach erosion were traditional shoreline protection by piling dead corals, sand sacks and woods on the beaches, modification and improvement to damaged building structures. Some local communities opted to move further inland and relocate to other islands or mainland Sabah to avoid the impacts of erosion. This study emphasizes the value of local knowledge shared by the coastal communities which can be incorporated with scientific baseline data for improved sustainable coastal development, protection, and management of the marine protected area.

An Automatic Individual Tree 3D Change Detection Method for Allometric Parameters Estimation in Mixed Uneven-Aged Forest Stands from ALS Data

Forests play a central role in the management of the Earth’s climate. Airborne laser scanning (ALS) technologies facilitate the monitoring of large and impassable areas and can be used to monitor the 3D structure of forests. While the ALS-based forest measures have been studied in depth, 3D change detection in forests is still a subject of little attention in the literature due to the challenges introduced by comparing point cloud pairs. In this study, we propose an innovative methodology to (i) automatically perform a 3D change detection of forests on an individual tree level; (ii) estimate tree parameters with allometric equations; and (iii) perform an assessment of the aboveground biomass (AGB) variation over time. The area in which the tests were carried out was hit by an ice storm that occurred in the time interval between the two LiDAR acquisitions; furthermore, field measurements were carried out and used to validate the results. The single-tree segmentation of the point clouds was automatically performed with a local maxima algorithm to detect the treetop, and a decision tree method to define the individual crowns around the local maxima. The multitemporal comparison of the point clouds was based on the identification of single trees, which were matched when there was a correlation between the position of the treetops. For each tree, the DBH (diameter at breast height) and the AGB were also estimated using allometric equations. The results are promising and allowed us to identify the uprooted trees and estimate that about 40% of the AGB of the area under examination had been destroyed, with an RMSE over the estimation ranging between 4% and 21% in four scenarios.

The Destructive Static Tree-Pulling Test Provides Reliable Estimates of the Soil–Root Plate of Eastern Baltic Silver Birch (Betula pendula Roth.)

Under the intensifying cyclonic activity, the wind resistance of European forests could be increased through science-based adaptive forest management, which requires the quantification of tree stability. In this regard, the dimensions of the soil–root plate can be directly attributed to tree wind resistance; however, naturally uprooted trees might be a biased source of information for the evaluation of adaptive measures due to uncontrolled conditions and uneven sample size. Therefore, the dimensions of the soil–root plates of naturally windthrown silver birch trees (Betula pendula Roth.) are compared to artificially overturned trees under a static tree-pulling test in Eastern Baltic region. The application of static tree-pulling overestimated the dimensions of the soil–root plates of silver birch compared to windthrown trees. The overestimation of soil–root plate dimensions was consistent spatially and across soil types, which is likely a regional adaptation to local wind climate. This implies that static tree-pulling is representative of the assessment of the effects of adaptive management on tree stability via the dimensions of the soil–root plates.

Impact of Timber Logging on Neighbouring Stands in a Forest of the South Western Cameroon

During conventional logging operations, there is always some damage to nearby stands. This study therefore assessed the damage caused after logging operations to surrounding stands in a Forest Management Unit (FMU) in south western Cameroon after logging operations. The damages assessed were snapped branches/trunks and uprooted trees. A total of 304 trees with a diameter ≥ 30 cm were cut and a total of 770 neighbouring harvestable and future trees were affected. It was observed that 375 of the neighbouring stand had their trunks snapped, 312 had their branches snapped, and 15 were uprooted. It was noted that 80% of the trees affected were those with diameters between 30 - 50 cm, which were called future trees for the next harvest, while the least damage was on protected/seed trees. Lophira alata caused the highest stand damage due to its abundance and large size, while Distemonanthus benthamianus caused the least domino damage. Damage to future trees negatively affects future concession holders as these trees are supposed to mature before the next harvest, hence the yield will be greatly reduced. Sustainable timber exploitation will greatly reduce residual damage as care will be taken to ensure falling timber causes less damage to the surrounding stand.

Estimation of deracinated trees area in temperate forest with satellite images employing machine learning methods.

Climate change can increase the number of uprooted trees. Although there have been an increasing number of machine learning applications for satellite image analysis, the estimation of deracinated tree area by satellite image is not well developed. Therefore, we estimated the deracinated tree area of forests via machine-learning classification using Landsat 8 satellite images. We employed support vector machines (SVMs), random forests (RF), and convolutional neural networks (CNNs) as potential machine learning methods, and tested their performance in estimating the deracinated tree area. We collected satellite images of upright trees, deracinated trees, soil, and others (e.g., waterbodies and cities), and trained them with the training data. We compared the accuracy represented by the correct classification rate of these methods, to determine the deracinated tree area. It was found that the SVM and RF performed better than the CNN for two-class classification (deracinated and upright trees), and the correct classification rates of all methods were up to 93%. We found that the CNN and RF performed significantly higher for the four- and two-class classification compared to the other methods, respectively. We conclude that the CNN is useful for estimating deracinated tree areas using Landsat 8 satellite images.

Recovery of Forest Structure Following Large-Scale Windthrows in the Northwestern Amazon

The dynamics of forest recovery after windthrows (i.e., broken or uprooted trees by wind) are poorly understood in tropical forests. The Northwestern Amazon (NWA) is characterized by a higher occurrence of windthrows, greater rainfall, and higher annual tree mortality rates (~2%) than the Central Amazon (CA). We combined forest inventory data from three sites in the Iquitos region of Peru, with recovery periods spanning 2, 12, and 22 years following windthrow events. Study sites and sampling areas were selected by assessing the windthrow severity using remote sensing. At each site, we recorded all trees with a diameter at breast height (DBH) ≥ 10 cm along transects, capturing the range of windthrow severity from old-growth to highly disturbed (mortality > 60%) forest. Across all damage classes, tree density and basal area recovered to >90% of the old-growth values after 20 years. Aboveground biomass (AGB) in old-growth forest was 380 (±156) Mg ha−1. In extremely disturbed areas, AGB was still reduced to 163 (±68) Mg ha−1 after 2 years and 323 (± 139) Mg ha−1 after 12 years. This recovery rate is ~50% faster than that reported for Central Amazon forests. The faster recovery of forest structure in our study region may be a function of its higher productivity and adaptability to more frequent and severe windthrows. These varying rates of recovery highlight the importance of extreme wind and rainfall on shaping gradients of forest structure in the Amazon, and the different vulnerabilities of these forests to natural disturbances whose severity and frequency are being altered by climate change.

Applicability evaluation of tree volume equation for Abies kawakamii (Hayata) Ito based on stem analysis data in Taiwan

ABSTRACT Abies kawakamii (Taiwan fir) typically constitutes pure forest distributed at 3,100–3,600 m above sea level in Taiwan. Its volume was first investigated in 1963 using aerial photography to identify the growing stock of the forest. In 1973, Taiwan Forestry Bureau established a fir volume estimation equation by considering Taiwan spruce and Taiwan fir stands. However, due to cutting natural forest is not permitted in Taiwan, it was difficult to reconstruct specific volume equation for Taiwan fir. We can only use and collect the uprooted trees as samples for this study by Typhoon Soudelor in 2015. We used these samples for estimation and used the remaining trees for verification and tested the suitability of six equations (models) for Taiwan fir volume estimation. We found that the Schumacher equation was suitable for juvenile trees, and the generalized combined-variable equation was suitable for semi-mature trees. The Schumacher equation (a logarithmic equation) and generalized combined-variable equation demonstrated the better suitability for volume estimation. However, when a juvenile was considered in the estimation, the generalized combined-variable equation provided underestimations. Thus, the Schumacher equation (V = aDbHc) was the better model for our test. The new tree volume estimation equation for Taiwan fir in the Mt. Xue region is presented as follows: .

Wind damage and yield recovery in rubber (Hevea brasiliensis) plantation

The recent study observed the damage type and the effect on the yield and dry rubber content (DRC) of wind damaged and one-year recovery of rubber trees. The observation covered 11 sites consisted of 8, 11, 12, and 15 years of PB 260 clone. The damage type was distinguished into curved, cracking curved, broken branch, broken stem, and uprooted. Latex samples were collected from each damage type and compared with normal trees. The observation exhibited that the broken stem and uprooted trees were found in the center of the impacted area, whereas curved and broken branch trees were located in the outer. The proportion of curved, broken branches and uprooted trees increased by plant age, while the proportion of broken stem decreased. The wind damage inflicted a significant yield loss and DRC decrease. The curved trees showed the least impact on the yield, yet it was reduced by nearly 50 %, and the DRC lower around 4.92 %. Nevertheless, when the curve was accompanied by cracking, the yield loss and the DRC decrease were more severe. The one-year recovery trees indicated that the trees did not fully recover.

Diversity and composition of moss guilds on uprooted trees in Central European mountain forests: effects of uprooting components and environmental variables

Key messageThe size of the structural components of the root–pit–mound complex was crucial for high moss species richness. Root plates, pits, and mounds were similar in terms of moss species composition, which was mostly determined by forest type.ContextUprooted trees may be colonized by different terricolous mosses including common species and specialists.AimsThe main aim of the present study was to analyze the relative effects of tree uprooting on mosses.MethodsWe used the parametric ZIGLMM and GLMM models to explain the richness and abundance of the moss species and double constrained correspondence analysis (dc-CA) to analyze species composition.ResultsThe size of components of RPM complexes had a positive effect on moss species richness. The species cover of mosses was positively correlated with elevation. Species richness was partly dependent on forest type and species cover on component type and age of the RPM complex. The most important factor diversifying species composition was the type of forest. Species traits were also related to forest communities.ConclusionUprooted trees are worth keeping in forest community, especially large ones. Moreover, the conservation value of uprooted trees in woodlands is higher if they are dispersed in different forest types.

云冷杉红松林掘根倒木及其微立地对凋落叶分解速率及养分释放的影响

采用凋落物分解袋埋藏法，将采集的红松（Pinus koraiensis）、紫椴（Tilia amurensis）和色木槭（Acer mono）凋落叶按自然比例混合装入袋中，于2019年7月将其埋入云冷杉红松林中不同腐烂等级（Ⅱ、Ⅲ、Ⅳ级）的掘根倒木（UT）及其形成的坑底（PB）与丘面（MF）以及对照（包括林隙（FG）和林分（IS））等11种微立地下。8-10月每月从每种微立地取回3袋，处理后测定凋落叶的质量、碳、氮、磷含量。采用相关分析和方差分析的统计分析方法，探究不同微立地下凋落叶的质量、分解速率与养分元素之间的相关性和差异显著性。结果表明：（1）微立地和分解时间对凋落叶质量具有极显著影响（P<0.01）。凋落叶分解90天后，各微立地的凋落叶质量残留率排列为：PB （85.64%） > MF （83.09%） > FG （81.33%） > IS （80.93%） > UT （80.27%）；（2）各微立地的凋落叶分解速率排列为：k_IS=k_UT>k_FG>k_MF>k_PB；Olson指数模型能够较好的模拟各微立地的凋落叶分解动态；年分解速率k为0.61-1.42，分解50%和95%所需时间分别为0.49-1.14 a和2.10-4.92 a。（3）各微立地的凋落叶C残留率总体呈下降趋势，表现为释放模式；UT和MF微立地的N、P残留率持续下降，表现为释放；PB微立地的N、P变化模式分别为释放-富集-释放、富集-释放模式，释放均大于富集，最终表现为释放模式。微立地对凋落叶P释放具有极显著影响（P<0.01），对N释放具有显著影响（P<0.05）；微立地与掘根倒木腐烂等级的交互作用对C、N释放均具有极显著的影响（P<0.01）。（4）凋落叶质量残留率与P的残留率在所有微立地中均存在显著或极显著正相关关系，与N的残留率仅在Ⅱ级UT、PB微立地、Ⅲ级UT微立地、Ⅳ级UT、PB和MF微立地以及FG对照中呈显著或极显著的正相关关系，与C的残留率仅在Ⅱ级UT、PB微立地、Ⅳ级PB、MF微立地中存在极显著或显著正相关关系，与C/N在Ⅱ级UT微立地、Ⅲ级UT、MF微立地和FG对照中呈显著或极显著负相关关系。可见，与不同腐烂等级的掘根倒木相比，掘根倒木形成的微立地环境对凋落叶分解和养分释放的影响较大。;Litter decomposition bag burial method is adopted in this study. The collected litters of Pinus koraiensis, Tilia amurensis, and Acer mono were mixed and packed into bags according to their natural proportion. These bags were buried under eleven different microsites, including uprooted trees (UT) with different decayed levels (Ⅱ, Ⅲ, Ⅳ) and their formed pit bottom (PB), mound face (MF) and the controls (forest gap (FG) and intact stand (IS)) in Picea koraiensis-Abies nephrolepis-Pinus koraiensis forest in July 2019. From August to October, three bags of each microsite were collected from each month. After treatment, the mass, C, N and P contents of litters were measured in the labs. Correlation analysis and variance analysis were used to explore their correlations and significance difference between the mass, decomposition rate and nutrient elements of litters at different microsites. The results showed that:(1) microsites and decomposition time had significant effects on the quality of litters(P<0.01). With continuous decomposition, the mass residual rates of litters in each microsite were arranged as follows:PB(85.64%) > MF(83.09%) > FG(81.33%) > IS(80.93%) > UT(80.27%). (2) Their decomposition rates were listed as follows k_IS=k_UT>k_FG>k_MF>k_PB; the Olson index model can simulate the decomposition dynamics of litters in each microsite. The annual decomposition rate k was 0.61-1.42, and the decomposition time required for 50% and 95% was 0.49-1.14 a and 2.10-4.92 a, respectively. (3) The retention rate of C in each microsite showed an overall downward trend, manifested as release mode. The residual rates of N and P in UT and MF microsites continued to decrease, N and P of litters were in the release mode. The change patterns of N and P elements in PB microsites were release-enrichment-release and enrichment-release, respectively. The release was greater than the enrichment, and the final expression was release mode. Microsites had a very significant effect on P release of litters(P<0.01), microsites had a significant effect on N release(P<0.05); the interaction between the microsite and the decay classes of uprooted treefalls had a significant effect on the release of C and N(P<0.01). (4) Retention rate of litter quality and the residual rate of P had a significant or extremely significant positive correlation in all microsites; Retention rate of litter quality and the residual rate of N had a significant or extremely significant positive correlation at level Ⅱ UT, PB microsites, level Ⅲ UT microsites, level Ⅳ UT, PB and MF microsites and FG control; Retention rate of litter quality and the residual rate of C had a significant or extremely significant positive correlation at level Ⅱ UT, PB microsites, Ⅳ PB, MF microsites; retention rate of litter quality and C/N had a significant or extremely significant negative correlation at level Ⅱ UT microsites, Ⅲ UT, MF microsites and FG control. It can be seen that the microsite environment formed by uprooted treefalls has a greater influence on the decomposition and nutrient release of litters than that different decay classes of uprooted treefalls.