scholarly journals Effects of natural broadleaved regeneration vs conifer restoration on the herb layer and microclimate

2016 ◽  
Vol 68 (3) ◽  
pp. 483-493
Author(s):  
Dragana Vukov ◽  
Zoran Galic ◽  
Marko Rucando ◽  
Milos Ilic ◽  
Mirjana Cuk ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Correspondence Analysis ◽  
Detrended Correspondence Analysis ◽  
Beech Forest ◽  
Douglas Fir ◽  
Pteridium Aquilinum ◽  
Permanent Plots ◽  
Herb Layer ◽  
Forest Stands ◽  
Floristic Similarity

This study was carried out on the Vidlic Mountain, eastern Serbia. The herb layer was surveyed in permanent plots on two localities: in a naturally regenerated beech forest and in a Douglas-fir plantation, in spring, summer and autumn 2011, 2012 and 2013. Air temperature, air humidity and soil moisture were measured. Species richness, Shannon?s diversity index and Pielou?s evenness index were calculated for each plot. Comparison of the abundances of species common to both forest stands was done using the Mann-Whitney U-test. The compositional gradient of the species data was examined using detrended correspondence analysis (DCA), and the species-environment relationship was analyzed by canonical correspondence analysis (CCA). Soil moisture and the total herb cover significantly differed in the naturally regenerated beech forest and Douglas-fir plantation. Floristic similarity between the surveyed forest stands was 28.12%. Although the dominant canopy species is known to be the strongest predictor of the herb layer, the model that includes all of the analyzed environmental factors explains the largest amount of the species variability. The species best fitted to this model are Dryopteris filix-mas, Galium odoratum, Pulmonaria officinalis, Sanicula europaea, Pteridium aquilinum and Rubus caesius. The analyzed forest stands are examples of two different post-disturbance regeneration strategies. Having in mind the limitations of this study, we can conclude that the naturally regenerated beech forest recovers faster: its herbaceous layer indicated nearly natural conditions, with only a few pioneer and disturbance-tolerant species. The herb layer in the Douglas-fir stand is still in the early seral stage, i.e. establishment.

Ordination by detrended correspondence analysis (DCA) of the vegetation of Swartboschkloof, Jonkershoek, Cape Province

Bothalia ◽  
1987 ◽  
Vol 17 (1) ◽  
pp. 121-129 ◽  
Author(s):  
D. J. Mcdonald
Keyword(s):  
Soil Moisture ◽  
Plant Communities ◽  
Correspondence Analysis ◽  
Detrended Correspondence Analysis ◽  
Vegetation Classification ◽  
Environmental Data ◽  
Strongly Correlated ◽  
Intensive Study ◽  
Dca Ordination ◽  
Soil Moisture Status

The data of a Braun-Blanquet vegetation classification was ordinated using detrended correspondence analysis (DCA). This was done at the Fynbos Biome intensive study site, Swartboschkloof, Jonkershoek, to investigate the factors determining the distribution of the plant communities. Superimposition of environmental data on the DCA ordination confirmed the indications of the Braun-Blanquet classification that the distribution of plant communities is most strongly correlated with soil geology and, to a lesser extent, with soil moisture status. The ordination also proved useful for examining the relationships between the transitional communites and the distinct communities of Swartboschkloof.

scholarly journals How do plant communities and flower visitors relate? A case study of semi-natural xerothermic grasslands

2013 ◽  
Vol 82 (2) ◽  
pp. 99-105 ◽  
Author(s):  
Damian Chmura ◽  
Paweł Adamski ◽  
Zygmunt Denisiuk
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Plant Communities ◽  
Correspondence Analysis ◽  
Positive Relationship ◽  
Detrended Correspondence Analysis ◽  
Permanent Plots ◽  
Moisture Index ◽  
Rarefaction Analysis ◽  
Flower Visitors

<p>The paper examines the relationships between the species composition of flower visitors and plants in the semi-natural xerothermic grasslands in southern and central Poland. Thirty 10 × 10 m permanent plots were laid out in total, mainly in nature reserves. The vegetation units studied were classified according to the Braun-Blanquet system; these were phytocoenoses of the <em>Festuco-Brometea</em> classes <em>Inuletum ensifoliae</em>, <em>Adonido-Brachypodietum pinnati</em> and the transitional plant community. Entomological research was performed using the Pollard method within the same plots. A particular site was visited only once and different sites were studied between April and August 2008. We applied, among others, co-correspondence-analysis Co-CA, detrended correspondence analysis (DCA) and redundancy analysis (RDA) to investigate the co-occurrence patterns of plants and flower visitors and their biotopic requirements. We found that the species composition of flower visitors cannot be predicted by floristic composition when the duration of the study is restricted to one day (but under similar weather conditions); however, there is a positive relationship between the species richness of insects and plants and a positive relationship between the number of plant species and the abundance of flower visitors. The Ellenberg moisture index and the cover of meadow species significantly explained the species composition of insects. The three various vegetation units and five dominant xerothermic species, i.e. <em>Adonis vernalis</em>, <em>Anemone sylvestris</em>, <em>Inula ensifolia</em>, <em>Linum hirsutum</em> and <em>Carlina onopordifolia</em> that were studied across time differed in the species richness of insects. Our results demonstrate that possible patterns in the species composition and the assembly rules of flower visitors are not apparent when the Pollard method is applied. Based on the data obtained using this method, the flower visiting assemblages seem not to be driven by competition and they primarily show a tendency to co-occur which can be an artifact. A plant-focused method that included a rarefaction analysis yielded more insightful results and shed more light on the differences between the dominant plants that shape the physiognomy of plant communities in a possible pollination specialization.</p>

Growth and yield of all-aged Douglas-fir – western hemlock forest stands: a matrix model with stand diversity effects

2005 ◽  
Vol 35 (10) ◽  
pp. 2368-2381 ◽  
Author(s):  
Jingjing Liang ◽  
Joseph Buongiorno ◽  
Robert A Monserud
Keyword(s):  
Species Diversity ◽  
Matrix Model ◽  
The United States ◽  
Douglas Fir ◽  
Growth And Yield ◽  
Western Hemlock ◽  
Permanent Plots ◽  
Forest Stands ◽  
Individual Tree ◽  
Size Diversity

A density-dependent matrix model was developed for Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) – western hemlock (Tsuga heterophylla (Raf.) Sarg.) forest stands in the Pacific Northwest of the United States. The model predicted the number and volume of trees for 4 species groups and 19 diameter classes. The parameters were based on species-dependent equations linking individual tree growth, mortality, and stand recruitment to tree and stand characteristics, including stand diversity in terms of tree species and size. The equations were estimated with individual tree and stand data from 2706 permanent plots in western Washington and Oregon, largely from private and state lands, measured twice at an average interval of 10 years. Other things being equal, diameter growth increased slightly with species diversity and decreased with size diversity. Recruitment increased with species diversity and decreased with size diversity. Mortality was independent of species diversity and tended to increase with size diversity. There was practically no relationship between individual tree volume and species or size diversity. The number of trees predicted by the model over the interval between successive inventories was generally unbiased. Long-term predictions with different initial conditions were consistent with standard yield tables and compared favorably with those of the Forest Vegetation Simulator. The model also implied that, independently of its initial condition, an undisturbed stand would eventually reach a steady state dominated by western hemlock more than 1 m in diameter, with few trees of other species and size.

scholarly journals Shift in the Spatio-Temporal Natural Fruiting of Boletes in West African Woodlands: the Key Role of the Soil Moisture

2020 ◽  
Author(s):  
Akotchayé Sylvestre Badou ◽  
Roel D. Houdanon ◽  
Kassim I. Tchan ◽  
D.M.T. Apollon Hègbè ◽  
Nourou Soulemane Yorou
Keyword(s):  
Species Richness ◽  
Soil Moisture ◽  
Ectomycorrhizal Fungi ◽  
Linear Models ◽  
Positive Influence ◽  
Permanent Plots ◽  
Data Logger ◽  
Fresh Biomass ◽  
Natural Production ◽  
Spatio Temporal

Abstract Background: The ectomycorrhizal fungi display strong fluctuations during the mycological season. However, how abiotic parameters affect the fruiting sequences of ectomycorrhizal fungi and also the direction and extent of this effect are not yet tapped adequately. The present study seeks to assess the microclimate effect on the natural production of boletes. Nine permanent plots of 2500 m2 (50m x 50m) split into 25 subplots of 100 m2 (10m x 10m) were installed in three different vegetation dominated respectively by Isoberlinia doka, Isoberlinia tomentosa and Uapaca togoensis. Microclimatic parameters were recorded each 30 minutes throughout by mean of a Micro Station Data Logger - H21-002 the mycological seasons. Each plot was surveyed twice a week (from May to October) over three years (2015, 2016 and 2017) to record the presence/absence of fruit bodies and fresh biomass of boletes. To evaluate the effect of time and microclimate variables on natural production, we used mixed effects and generalized linear models using R version 3.5.3. Results: In total, during the three years (2015, 2016 and 2017), we recorded 14 species of boletes. Species richness does not change over time (P > 0.05). In addition, fresh biomass varies within years and vegetation (P < 0.05). The combination of year and month of collection has a significant effect on the number of fruit bodies (P < 0.05). Only the soil moisture has a significant positive influence on the species richness of boletes (P > 0.05). Conclusions: When the soil moisture decreases by four units, the number of fruit bodies of ectomycorrhizal fungi is significantly reduced by one unit. Therefore, above 0.25 m3 / m3 and below 0.05 m3 / m3 there is a decrease in the number of fruit bodies.

scholarly journals Identification of the important environmental factors influencing natural vegetation succession following cropland abandonment on the Loess Plateau, China

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e10349
Author(s):  
Zhenguo Zhang ◽  
Mingming Wang ◽  
Jikai Liu ◽  
Xinwei Li
Keyword(s):  
Loess Plateau ◽  
Correspondence Analysis ◽  
Classification Tree ◽  
Detrended Correspondence Analysis ◽  
Vegetation Succession ◽  
Natural Vegetation ◽  
Vegetation Types ◽  
The Loess Plateau ◽  
Cropland Abandonment

Identification of typical vegetation succession types and their important influencing factors is an important prerequisite to implement differential vegetation and soil management after land abandonment on the Loess Plateau, China. However, there is no reported study specifically on the identification of vegetation types and their important factors as well as the thresholds of the important factors for classification of the vegetation types, based on the medium- to long-term succession of natural vegetation after cropland abandonment. We collected vegetation and soil data on the natural vegetation with the longest 60-year-old forest communities that developed after cropland abandonment and analyzed the data using two-way indicator species analysis, detrended correspondence analysis, direct canonical correspondence analysis and classification tree model. The vegetation communities were classified into five distinct vegetation types, including Artemisia scoparia, Lespedeza davurica and Stipa bungeana, Artemisia giraldii pamp, Sophora viciifolia, Quercus liaotungensis and Biota orientalis. The years after cropland abandonment and soil C/N were further identified as important factors determining the types of vegetation. Likewise, it was observed that most of the investigated soil nutrient variables and soil texture-related variables improved with the vegetation succession while soil water in the surface layers showed a decreasing trend. These findings may provide an ecological basis for site-specific management of vegetation types after cropland abandonment in the medium-long term on the Loess Plateau. Our results encourage further exploration of vegetation succession and their important factors based on longer periods of vegetation succession after cropland abandonment under more soil and climatic conditions on the mountainous areas as the Loess Plateau.

scholarly journals L-Band Vegetation Optical Depth Estimation Using Transmitted GNSS Signals: Application to GNSS-Reflectometry and Positioning

2020 ◽  
Vol 12 (15) ◽  
pp. 2352
Author(s):  
Adriano Camps ◽  
Alberto Alonso-Arroyo ◽  
Hyuk Park ◽  
Raul Onrubia ◽  
Daniel Pascual ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Optical Depth ◽  
Vegetation Index ◽  
Elevation Angle ◽  
Depth Estimation ◽  
Beech Forest ◽  
Global Navigation Satellite Systems ◽  
Area Index ◽  
Vegetation Impact ◽  
L Band

At L-band (1–2 GHz), and particularly in microwave radiometry (1.413 GHz), vegetation has been traditionally modeled with the τ-ω model. This model has also been used to compensate for vegetation effects in Global Navigation Satellite Systems-Reflectometry (GNSS-R) with modest success. This manuscript presents an analysis of the vegetation impact on GPS L1 C/A (coarse acquisition code) signals in terms of attenuation and depolarization. A dual polarized instrument with commercial off-the-shelf (COTS) GPS receivers as back-ends was installed for more than a year under a beech forest collecting carrier-to-noise (C/N0) data. These data were compared to different ground-truth datasets (greenness, blueness, and redness indices, sky cover index, rain data, leaf area index or LAI, and normalized difference vegetation index (NDVI)). The highest correlation observed is between C/N0 and NDVI data, obtaining R2 coefficients larger than 0.85 independently from the elevation angle, suggesting that for beech forest, NDVI is a good descriptor of signal attenuation at L-band, which is known to be related to the vegetation optical depth (VOD). Depolarization effects were also studied, and were found to be significant at elevation angles as large as ~50°. Data were also fit to a simple τ-ω model to estimate a single scattering albedo parameter (ω) to try to compensate for vegetation scattering effects in soil moisture retrieval algorithms using GNSS-R. It is found that, even including dependence on the elevation angle (ω(θe)), at elevation angles smaller than ~67°, the ω(θe) model is not related to the NDVI. This limits the range of elevation angles that can be used for soil moisture retrievals using GNSS-R. Finally, errors of the GPS-derived position were computed over time to assess vegetation impact on the accuracy of the positioning.

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