scholarly journals Waldindikatoren zur Artenvielfalt – Erkenntnisse aus LFI und BDM Schweiz | Forest structures and species diversity – Findings from the NFI and BDM

2007 ◽  
Vol 158 (8) ◽  
pp. 243-254 ◽  
Author(s):  
Urs-Beat Brändli ◽  
Christoph Bühler ◽  
Adrian Zangger
Keyword(s):  
Species Diversity ◽  
Vascular Plants ◽  
Monitoring Program ◽  
Stand Density ◽  
Species Group ◽  
National Forest Inventory ◽  
Study Data ◽  
Species Density ◽  
Site Factors ◽  
Forest Inventories

In order to monitor species diversity, surveying indicators in habitats has often been recommended as more cost efficient than assessing species directly. In this study data from the Swiss National Forest Inventory (NFI)and the Biodiversity Monitoring Program (BDM) were used to verify the correlation of species density for vascular plants, mosses, and molluscs with 58 variables of forest structure, site conditions and forest management. The analyses show that site factors, in particular the biogeographic regions, the altitude, slope and the soil acidity,explain 18 to 49% of the observed variance in species density, depending on the species group (taxon). Of all the factors influenced by management, only the availability of light (stand density) was found to play an important role primarily on vascular plants. In addition the density of molluscs is positively correlated to shrub cover. However, none of the regression models tested explains more than 54% of the variance of species density. Therefore, the authors conclude that the species richness of the species groups investigated can be assessed reliably only by direct survey. The analyses confirm that certain data assessed in forest inventories is ecologically very important and relevant for environmental policy.

scholarly journals Enhancing the precision of broad-scale forestland removals estimates with small area estimation techniques

2021 ◽  
Author(s):  
John W Coulston ◽  
P Corey Green ◽  
Philip J Radtke ◽  
Stephen P Prisley ◽  
Evan B Brooks ◽  
...  
Keyword(s):  
Small Area ◽  
Small Area Estimation ◽  
Species Group ◽  
Tree Cover ◽  
Estimation Techniques ◽  
Spatial And Temporal Scales ◽  
Area Estimation ◽  
Forest Inventories ◽  
Southeastern Us ◽  
Increasing Demand

Abstract National Forest Inventories (NFI) are designed to produce unbiased estimates of forest parameters at a variety of scales. These parameters include means and totals of current forest area and volume, as well as components of change such as means and totals of growth and harvest removals. Over the last several decades, there has been a steadily increasing demand for estimates for smaller geographic areas and/or for finer temporal resolutions. However, the current sampling intensities of many NFI and the reliance on design-based estimators often leads to inadequate precision of estimates at these scales. This research focuses on improving the precision of forest removal estimates both in terms of spatial and temporal resolution through the use of small area estimation techniques (SAE). In this application, a Landsat-derived tree cover loss product and the information from mill surveys were used as auxiliary data for area-level SAE. Results from the southeastern US suggest improvements in precision can be realized when using NFI data to make estimates at relatively fine spatial and temporal scales. Specifically, the estimated precision of removal volume estimates by species group and size class was improved when SAE methods were employed over post-stratified, design-based estimates alone. The findings of this research have broad implications for NFI analysts or users interested in providing estimates with increased precision at finer scales than those generally supported by post-stratified estimators.

Realized and potential efficiency for post-stratified estimation in a national forest inventory

2021 ◽  
Author(s):  
James A. Westfall ◽  
Andrew J. Lister ◽  
John W. Coulston ◽  
Ronald E. McRoberts
Keyword(s):  
Remotely Sensed ◽  
National Forest Inventory ◽  
Data Types ◽  
Remotely Sensed Data ◽  
Large Area ◽  
Forest Inventories ◽  
Temporal Misalignment ◽  
Total Tree ◽  
Potential Efficiency ◽  
Post Stratification

Post-stratification is often used to increase the precision of estimates arising from large-area forest inventories with plots established at permanent locations. Remotely sensed data and associated spatial products are often used for developing the post-stratification, which offers a mechanism to increase precision for less cost than increasing the sample size. While important variance reductions have been shown from post-stratification, it remains unknown where observed gains lie along the continuum of possible gains. This information is needed to determine whether efforts to further improve post-stratification outcomes are warranted. In this study, two types of ‘optimal’ post-stratification were compared to typical production-based post-stratifications to estimate the magnitude of remaining gains possible. Although the ‘optimal’ post-stratifications were derived using methods inappropriate for operational usage, the results indicated that substantial further increases in precision for estimates of both forest area and total tree biomass could be obtained with better post-stratifications. The potential gains differed by the attribute being estimated, the population being studied, and the number of strata. Practitioners seeking to optimize post-stratification face challenges such as evaluation of numerous auxiliary data sources, temporal misalignment between plot observations and remotely sensed data acquisition, and spatial misalignment between plot locations and remotely sensed data due to positional errors in both data types.

scholarly journals PHYTOSOCIOLOGICAL ANALYSIS AND FLORISTRIC DIVERSITY OF VANEESWARAM KAVU IN KANNUR DISTRICT, KERALA

2017 ◽  
Vol 4 (2) ◽  
pp. 19-23
Author(s):  
Jeeshna M.V
Keyword(s):  
Quantitative Analysis ◽  
Species Diversity ◽  
Medicinal Plants ◽  
Vascular Plants ◽  
Quantitative Approach ◽  
Sacred Grove ◽  
Sacred Groves ◽  
Conservation Of Biodiversity

Sacred groves act as a treasure house for rare and medicinal plants. Apart from the quantitative analysis quantitative approach to sacred grove gives the potential species and importance of sacred grove, which is the main focuses of this work. There are many sacred grooves are present at Kannur district in whichVaneeswaram Kavu is one of the important one. The flora of sacred groves of has analysed taxonomically and phytosociologically. A total of 64 vascular plants falling under 61 genera and 43 families were documented. About 12 species are reported in the red listed category. In phytosociological studies specieslike, Elaeocarpus serratus, Erycibe paniculata and Scleria lithosperma were showing higher IVI. The devastation of species diversity in the study area represent there is an urgent need for regeneration of the species for conservation of biodiversity.

scholarly journals Zur Auswirkung der Hangneigungskorrektur auf Schätzwerte im Schweizerischen Landesforstinventar (LFI) | Investigation of the effect of the slope correction method as applied in the Swiss National Forest Inventory of estimates

2001 ◽  
Vol 152 (6) ◽  
pp. 215-225 ◽  
Author(s):  
Michael Köhl ◽  
Peter Brassel
Keyword(s):  
Forest Inventory ◽  
Basal Area ◽  
Correction Method ◽  
National Forest Inventory ◽  
National Forest ◽  
Average Deviation ◽  
Forest Inventories ◽  
Slope Correction ◽  
Number Of Stems ◽  
Elliptical Area

For forest inventories on slopes, it is necessary to correct the test areas, because the circular areas, when projected, become elliptical. Based on 93 samples from the Swiss National Forest Inventory (FNI), it was determined whether the simplified method, which increases the radius to match that of the elliptical area, leads to a distortion of the results. An average deviation of 2% was found between the FNI estimated values and the actual values for the basal area and the number of stems. For estimations of smaller units, greater distortions of the results are expected.

Tree diversity and natural regeneration in Tropical Dry Deciduous Forest of Panna Tiger Reserve, India

2021 ◽  
Author(s):  
Talat Parveen ◽  
Orus Ilyas
Keyword(s):  
Species Diversity ◽  
Tree Species ◽  
Deciduous Forest ◽  
Basal Area ◽  
Stand Density ◽  
Tectona Grandis ◽  
Aegle Marmelos ◽  
Tree Stand ◽  
Tiger Reserve ◽  
Dry Deciduous Forest

Abstract The disturbance is a major factor driving the decline of tropical forests and their associated fauna. Henceforth, basic information on species diversity would be useful for assessing the success of management in the fragmented and human-disturbed landscape. We accounted for tree species diversity and their regeneration pattern from the tropical dry deciduous forest of Panna Tiger Reserve (PTR), India. Considering this, random vegetation sampling along with transects was carried out in different ranges of PTR. It is spread over in an area of 2998.98 km2 that situated in the northern part of Madhya Pradesh and distributed in Panna and Chhatarpur district. The tropical dry deciduous forest inventory in the 10.6132-ha area yielded a total of 46 woody species of > 10 cm GBH, belonged to 23 Families and 40 genera. The regeneration represented 27 species of < 30 cm height (seedling) under 16 families and 24 genera while sapling, which ranges from > 30cm to 1.3m, showed 24 species of 13 families and 32 genera. The Shannon diversity of Trees, seedlings, and saplings was 2.684, 2.525, and 2.401 respectively. A total stand density and basal area of 2391 stems of trees were estimated as 225.285 stand ha− 1 and 90.016 m2ha− 1 respectively. Tectona grandis scored the highest IVI value of 59.44 (19.81% of total IVI for all species) among the dominated tree species, followed by Acacia catechu (24.94), Abrus precatorius (23.25), Zizyphus xylopyra (22.94), Anogeissus latifolia (22.16) and Lagerstroemia parviflora (22.18). Nearly 23.913% of the total number of species was recorded as rare species. The highest seedling density was obtained for Diospyros melanoxylon followed by Zizyphus xylopyra, Aegle marmelos, Wrightia tintoria, and Tectona grandis, which declined in the subsequent sapling stage and showed a reverse pattern. Hence, the highest sapling density was recorded for Tectona grandis then Aegle marmelos, Wrightia tintoria, Diospyros melanoxylon, and Zizyphus xylopyra. A total of 36.956% of tree species were found to fail to establish in the community because species were represented by only adult or tree stage that listed as Not-regenerating. In terms of the most diverse family among the plant categories; viz. Tree, Seedling, Sapling, Fabaceae had the highest species richness. The highest tree stand density (127.576 stand ha− 1) was recorded in the girth class of 31-60cm (48.687% of the total tree stand density) followed by 10-30cm and 61-90cm. Likewise, a total basal area of 20.824 m2ha− 1 was occupied by 31-60cm that contributed 23.051% of the total basal area, so our data on the population structure of forest shows a similar trend wherein the distribution curve exponentially decreases with increasing girth classes that indicates not only a mid-successional forest but also a human-disturbed.

Estimating Trend in Occupancy for the Southern Sierra Fisher Martes pennanti Population

2013 ◽  
Vol 4 (1) ◽  
pp. 3-19 ◽  
Author(s):  
William J. Zielinski ◽  
James A. Baldwin ◽  
Richard L. Truex ◽  
Jody M. Tucker ◽  
Patricia A. Flebbe
Keyword(s):  
Sierra Nevada ◽  
Habitat Degradation ◽  
Monitoring Program ◽  
National Forest Inventory ◽  
Small Population ◽  
Probability Of Detection ◽  
Martes Pennanti ◽  
Entire Study ◽  
Significant Difference ◽  
The One

Abstract Carnivores are important elements of biodiversity, not only because of their role in transferring energy and nutrients, but also because they influence the structure of the communities where they occur. The fisher Martes pennanti is a mammalian carnivore that is associated with late-successional mixed forests in the Sierra Nevada in California, and is vulnerable to the effects of forest management. As a candidate for endangered species status, it is important to monitor its population to determine whether actions to conserve it are successful. We implemented a monitoring program to estimate change in occupancy of fishers across a 12,240-km2 area in the southern Sierra Nevada. Sample units were about 4 km apart, consisting of six enclosed, baited track-plate stations, and aligned with the national Forest Inventory and Analysis grid. We report here the results of 8 y (2002–2009) of sampling of a core set of 223 sample units. We model the combined effects of probability of detection and occupancy to estimate occupancy, persistence rates, and trend in occupancy. In combined models, we evaluated four forms of detection probability (1-group and 2-group both constant and varying by year) and nine forms of probability of occupancy (differing primarily by how occupancy and persistence vary among years). The best-fitting model assumed constant probability of occupancy, constant persistence, and two detection groups (AIC weight  =  0.707). This fit the data best for the entire study area as well as two of the three distinct geographic zones therein. The one zone with a trend parameter found no significant difference from zero for that parameter. This suggests that, over the 8-y period, that there was no trend or statistically significant variations in occupancy. The overall probability of occupancy, adjusted to account for uncertain detection, was 0.367 (SE  =  0.033) and estimates were lowest in the southeastern zone (0.261) and highest in the southwestern zone (0.583). Constant and positive persistence values suggested that sample units rarely changed status from occupied to unoccupied or vice versa. The small population of fishers in the southern Sierra (probably &lt;250 individuals) does not appear to be decreasing. However, given the habitat degradation that has occurred in forests of the region, we favor continued monitoring to determine whether fisher occupancy increases as land managers implement measures to restore conditions favorable to fishers.

First description of the female of Acantholycosa logunovi (Araneae: Lycosidae)

Zootaxa ◽  
2011 ◽  
Vol 2813 (1) ◽  
pp. 65 ◽  
Author(s):  
ALEXANDER A. FOMICHEV ◽  
YURI M. MARUSIK
Keyword(s):  
Species Diversity ◽  
Related Species ◽  
Wolf Spider ◽  
Species Group ◽  
Senior Author ◽  
Northern Asia ◽  
Mountain System ◽  
Sayan Mountain

With 26 named species (Platnick 2011), Acantholycosa Dahl, 1908 is a relatively large Holarctic genus in the wolf spider subfamily Pardosinae Simon, 1898. Acantholycosa was recently revised and 17 species were described as new to science (Marusik et al. 2004). The majority of species occur in Northern Asia and the highest species diversity is known from the Altai-Sayan Mountain System (18 species) (Marusik et al., 2004). Among the newly described species was Acantholycosa logunovi Marusik, Azarkina & Koponen, 2004 from Altai in Russia. The female epigyne of this species was found to be remarkably similar to those of A. norvegica (Thorell, 1872), while male palp was similar to those in A. plumalis species group. While collecting spiders in Altai the senior author collected over a dozen specimens belonging to Acantholycosa of which one pair was in copula. Study of this material revealed that males were conspecific with figures of the holotype of A. logunovi, but that females were different from those illustrated by Marusik et al. (2004). The females described as A. logunovi by Marusik et al. (2004) are instead A. norvegica and therefore females of A. logunovi remained undescribed up until now. Here we describe the female of A. logunovi, provide comparisons with related species and add to the known localities of this species.

scholarly journals A Nonlinear Mixed-Effects Height-to-Diameter Ratio Model for Several Tree Species Based on Czech National Forest Inventory Data

Forests ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 70 ◽  
Author(s):  
Ram Sharma ◽  
Zdeněk Vacek ◽  
Stanislav Vacek ◽  
Miloš Kučera
Keyword(s):  
Forest Inventory ◽  
Stand Density ◽  
Development Stage ◽  
National Forest Inventory ◽  
Mixed Effects ◽  
Site Quality ◽  
National Forest ◽  
Stand Development ◽  
Inventory Data ◽  
Canopy Layer

Height-to-diameter at breast height (DBH) ratio (HDR) is an important tree and stand stability measure. Several factors such as stand dynamics, natural and anthropogenic disturbances, and silvicultural tending significantly affect HDR, and, therefore, in-depth investigation of HDR is essential for better understanding of ecological processes in a forest. A nonlinear mixed-effects HDR model applicable to several tree species was developed using the Czech national forest inventory data comprising 13,875 sample plots and 348,980 trees. The predictive performance of this model was evaluated using the independent dataset which was originated from 25,146 trees on 220 research sample plots. Among various tree- and stand-level variables describing tree size, site quality, stand development stage, stand density, inter-tree spacing, and competition evaluated, dominant height (HDOM), dominant diameter (DDOM), relative spacing index (RS), and DBH-to-quadratic mean DBH ratio (dq) were identified as the most important predictors of HDR variations. A random component describing sample plot-specific HDR variations was included through mixed-effects modelling, and dummy variables describing species-specific HDR variations and canopy layer-specific HDR variations were also included into the HDR model through dummy variable modelling. The mixed-effects HDR model explained 79% of HDR variations without any significant trends in the residuals. Simulation results showed that HDR for each canopy layer increased with increasing site quality and stand development stage (increased HDOM) and increasing competition (increased RS, decreased DDOM and dq). Testing the HDR model on the independent data revealed that more than 85% of HDR variations were described for each individual species (Norway spruce, Scots pine, European larch, and European beech) and group of species (fir species, oak species, birch and alder species) without significant trends in the prediction errors. The HDR can be predicted with a higher accuracy using the calibrated mixed-effects HDR model from measurements of its predictors that can be obtained from routine forest inventories. To improve the prediction accuracy, a model needs to be calibrated with the random effects estimated using one to four randomly selected trees of a particular species or group of species depending on the availability of their numbers per sample plot. The HDR model can be applied for stand stability assessment and stand density regulation. The HDR information is also useful for designing a stand density management diagram. Brief implications of the HDR model for designing silviculture strategies and forest management planning are presented in the article.

scholarly journals The Influence of Tree Structural and Species Diversity on Temperate Forest Productivity and Stability in Korea

Forests ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 1113 ◽  
Author(s):  
Juhan Park ◽  
Hyun Seok Kim ◽  
Hyun Kook Jo ◽  
II Bin Jung
Keyword(s):  
Species Diversity ◽  
Tree Species ◽  
Temperate Forest ◽  
Temperate Forests ◽  
Basal Area ◽  
Stand Density ◽  
Structural Diversity ◽  
Forest Productivity ◽  
Tree Species Diversity ◽  
Positive Effect

Research Highlights: Using a long-term dataset on temperate forests in South Korea, we established the interrelationships between tree species and structural diversity and forest productivity and stability, and identified a strong, positive effect of structural diversity, rather than tree species diversity, on productivity and stability. Background and Objectives: Globally, species diversity is positively related with forest productivity. However, temperate forests often show a negative or neutral relationship. In those forests, structural diversity, instead of tree species diversity, could control the forest function. Materials and Methods: This study tested the effects of tree species and structural diversity on temperate forest productivity. The basal area increment and relative changes in stand density were used as proxies for forest productivity and stability, respectively. Results: Here we show that structural diversity, but not species diversity, had a significant, positive effect on productivity, whereas species diversity had a negative effect, despite a positive effect on diversity. Structural diversity also promoted fewer changes in stand density between two periods, whereas species diversity showed no such relation. Structurally diverse forests might use resources efficiently through increased canopy complexity due to canopy plasticity. Conclusions: These results indicate reported species diversity effects could be related to structural diversity. They also highlight the importance of managing structurally diverse forests to improve productivity and stability in stand density, which may promote sustainability of forests.

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