scholarly journals Phytoclimatic Stages and Vegetation in Baden - Württemberg and Emilia - Romagna

2019 ◽  
Vol 67 ◽  
pp. 1-30
Author(s):  
Dario Botti
Keyword(s):  
Environmental Analysis ◽  
Regional Scale ◽  
Landscape Analysis ◽  
Vegetation Types ◽  
Climatic Parameters ◽  
One Stage ◽  
Ecological Regionalization ◽  
Broad Type

The assessment of ecosystems and landscapes requires reliable and simple tools. Climate determines broad type and distribution of ecosystems. Therefore, it is a major factor to consider in environmental analysis and ecological regionalization. A standardized bioclimatic classification would be useful to characterize and compare different ecosystems. In this paper, Defaut’s Phytoclimatic System (DSPS) was tested at regional scale in two European areas: Baden-Württemberg (Germany) and Emilia-Romagna (Italy). DSPS phytoclimatic units and vegetation belts and climatic parameters are illustrated and discussed. In addition, as an example application, a map of phytoclimatic units of Emilia-Romagna is designed. Some challenges in matching vegetation to DSPS were found: 1) in areas where transition from one stage to another are not sharply delineated and different vegetation types are intermixed; 2) in alluvial lowlands; 3) in heavily anthropized areas. In conclusion, the results of this study suggest that DSPS can be a useful tool in ecological regionalization and in landscape analysis.

The Use of Ecological Tolerances for the Reconstruction of Tertiary Palaeoclimates

1997 ◽  
Vol 45 (3) ◽  
pp. 475 ◽  
Author(s):  
Helene A. Martin
Keyword(s):  
Vegetation Types ◽  
Climatic Parameters ◽  
Salt Tolerant ◽  
Pollen Assemblage ◽  
Pollen Types ◽  
Living Species ◽  
Marine Influence ◽  
Lagarostrobos Franklinii ◽  
Single Living ◽  
Very High

The major vegetation types may be recognised from the pollen assemblage being deposited beneath them, hence the palaeovegetation may be reconstructed from fossil pollen assemblages. The climatic parameters of the vegetation may then be used to reconstruct palaeoclimates. The result, however, is very general. Most pollen types can only be affiliated with a family, a genus or a group of species and the ecological tolerances within these groups may not be uniform. There are, however, some distinctive pollen types that can be identified with a single living species and this paper examines the potential of these types in the reconstruction of palaeoclimates. Lagarostrobos franklinii (J.D.Hook) Quinn, Huon pine, has a long history and the fossil occurrences of it are compatible with the hypothesis that its ecological tolerances have not changed and it has always required very high humidity. Two sclerophyllous taxa,Eucalyptus spathulata Hook. and Dodonaea triquetra Wendl., however, coexisted with rainforest and then other vegetation types as the climate became drier, adapting to the prevailing conditions. The evidence suggests that the salt-tolerant E. spathulata may have evolved in small patches of coastal scrub, subjected to marine influence, within the dominant rainforest vegetation.

scholarly journals Effects of Distinguishing Vegetation Types on the Estimates of Remotely Sensed Evapotranspiration in Arid Regions

2019 ◽  
Vol 11 (23) ◽  
pp. 2856 ◽  
Author(s):  
Tao Du ◽  
Li Wang ◽  
Guofu Yuan ◽  
Xiaomin Sun ◽  
Shusen Wang
Keyword(s):  
Water Resource Management ◽  
Regional Scale ◽  
Great Influence ◽  
Populus Euphratica ◽  
Remotely Sensed ◽  
Arid Ecosystems ◽  
Tamarix Ramosissima ◽  
Estimation Accuracy ◽  
Vegetation Types ◽  
The Difference

Accurate estimates of evapotranspiration (ET) in arid ecosystems are important for sustainable water resource management due to competing water demands between human and ecological environments. Several empirical remotely sensed ET models have been constructed and their potential for regional scale ET estimation in arid ecosystems has been demonstrated. Generally, these models were built using combined measured ET and corresponding remotely sensed and meteorological data from diverse sites. However, there are usually different vegetation types or mixed vegetation types in these sites, and little information is available on the estimation uncertainty of these models induced by combining different vegetation types from diverse sites. In this study, we employed the most popular one of these models and recalibrated it using datasets from two typical vegetation types (shrub Tamarix ramosissima and arbor Populus euphratica) in arid ecosystems of northwestern China. The recalibration was performed in the following two ways: using combined datasets from the two vegetation types, and using a single dataset from specific vegetation type. By comparing the performance of the two methods in ET estimation for Tamarix ramosissima and Populus euphratica, we investigated and compared the accuracy of ET estimation at the site scale and the difference in annual ET estimation at the regional scale. The results showed that the estimation accuracy of daily, monthly, and yearly ET was improved by distinguishing the vegetation types. The method based on the combined vegetation types had a great influence on the estimation accuracy of annual ET, which overestimated annual ET about 9.19% for Tamarix ramosissima and underestimated annual ET about 11.50% for Populus euphratica. Furthermore, substantial difference in annual ET estimation at regional scale was found between the two methods. The higher the vegetation coverage, the greater the difference in annual ET. Our results provide valuable information on evaluating the estimation accuracy of regional scale ET using empirical remotely sensed ET models for arid ecosystems.

scholarly journals Leaf wax <i>n</i>-alkanes in modern plants and topsoils from eastern Georgia (Caucasus) – implications for reconstructing regional paleovegetation

2017 ◽  
Author(s):  
Marcel Bliedtner ◽  
Imke K. Schäfer ◽  
Roland Zech ◽  
Hans von Suchodoletz
Keyword(s):  
Regional Scale ◽  
Chemical Degradation ◽  
Vegetation Types ◽  
Terrestrial Plants ◽  
Caucasus Region ◽  
Leaf Wax ◽  
South Eastern Europe ◽  
Southern Caucasus ◽  
Physical And Chemical ◽  
Long Chain

Abstract. Long-chain n-alkanes became increasingly used for paleoenvironmental studies during the last years as they have the great potential to reconstruct past changes in vegetation and climate. They mostly originate from leaf waxes of higher terrestrial plants, are relatively resistant against physical and chemical degradation and can thus serve as valuable biomarkers that are preserved in various sedimentary archives for at least millennial timescales. However, before any robust interpretation of the long-chain n-alkane patterns in sedimentary archives, reference samples from modern vegetation and topsoil material should be investigated at a regional scale. Apart from Central and South-Eastern Europe, such systematic regional studies on modern plant and topsoil material are still largely lacking. To test the potential of leaf wax derived n-alkane patterns for paleoenvironmental studies in the semi-humid to semi-arid southern Caucasus region, we investigated the influence of different vegetation types on the leaf wax n-alkane signal in modern plants and topsoil material (0–5 cm) from eastern Georgia. We sampled (i) sites with grassland that included steppe, cultivated grassland and meadows, and (ii) sites that are dominated by deciduous hornbeam forests. The n-alkane results show distinct and systematic differences between samples from sites with the different vegetation types: n-alkanes derived from sites with grassland are mainly dominated by C31, while n-alkanes derived from sites with deciduous trees show high abundances of C29. Thus, chain-length ratios allow to discriminate between these two different vegetation types and have a great potential when used for regional paleoenvironmental reconstructions. As degradation of organic matter can affect the leaf wax n-alkane distribution, we further present an updated end-member model that includes our results, accounts for degradation effects and enables semi-quantitative reconstruc-tions of past vegetation changes in the southern Caucasus region.

scholarly journals Mapping Congo Basin vegetation types from 300 m and 1 km multi-sensor time series for carbon stocks and forest areas estimation

2012 ◽  
Vol 9 (12) ◽  
pp. 5061-5079 ◽  
Author(s):  
A. Verhegghen ◽  
P. Mayaux ◽  
C. de Wasseige ◽  
P. Defourny
Keyword(s):  
Land Cover ◽  
Atlantic Coast ◽  
Regional Scale ◽  
Carbon Stocks ◽  
Congo Basin ◽  
Tree Cover ◽  
Temporal Consistency ◽  
Vegetation Types ◽  
Forest Types ◽  
Surface Areas

Abstract. This study aims to contribute to the understanding of the Congo Basin forests by delivering a detailed map of vegetation types with an improved spatial discrimination and coherence for the whole Congo Basin region. A total of 20 land cover classes were described with the standardized Land Cover Classification System (LCCS) developed by the FAO. Based on a semi-automatic processing chain, the Congo Basin vegetation types map was produced by combining 19 months of observations from the Envisat MERIS full resolution products (300 m) and 8 yr of daily SPOT VEGETATION (VGT) reflectances (1 km). Four zones (north, south and two central) were delineated and processed separately according to their seasonal and cloud cover specificities. The discrimination between different vegetation types (e.g. forest and savannas) was significantly improved thanks to the MERIS sharp spatial resolution. A better discrimination was achieved in cloudy areas by taking advantage of the temporal consistency of the SPOT VGT observations. This resulted in a precise delineation of the spatial extent of the rural complex in the countries situated along the Atlantic coast. Based on this new map, more accurate estimates of the surface areas of forest types were produced for each country of the Congo Basin. Carbon stocks of the Basin were evaluated to a total of 49 360 million metric tons. The regional scale of the map was an opportunity to investigate what could be an appropriate tree cover threshold for a forest class definition in the Congo Basin countries. A 30% tree cover threshold was suggested. Furthermore, the phenology of the different vegetation types was illustrated systematically with EVI temporal profiles. This Congo Basin forest types map reached a satisfactory overall accuracy of 71.5% and even 78.9% when some classes are aggregated. The values of the Cohen's kappa coefficient, respectively 0.64 and 0.76 indicates a result significantly better than random.

scholarly journals Variability in <sup>14</sup>C contents of soil organic matter at the plot and regional scale across climatic and geologic gradients

2016 ◽  
Author(s):  
T. S. van der Voort ◽  
F. Hagedorn ◽  
C. McIntyre ◽  
C. Zell ◽  
L. Walthert ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Soil Depth ◽  
Regional Scale ◽  
Mean Annual Temperature ◽  
Spatial And Temporal Variability ◽  
Climatic Parameters ◽  
Soil Carbon Dynamics ◽  
Modelling Assumptions ◽  
Micro Topography

Abstract. Soil organic matter (SOM) forms the largest terrestrial pool of carbon outside of sedimentary rocks. Radiocarbon is a powerful tool for assessing soil organic matter dynamics. However, due to the nature of the measurement, extensive 14C studies of soils systems remain relatively rare. In particular, information on the extent of spatial and temporal variability in 14C contents of soils is limited, yet this information is crucial for establishing the range of baseline properties and for detecting potential modifications to the SOM pool. This study describes a comprehensive approach to explore heterogeneity in bulk SOM 14C in Swiss forest soils that encompass diverse landscapes and climates. We examine spatial variability in soil organic carbon (SOC) 14C, SOC content and C:N ratios over both regional climatic and geologic gradients, on the watershed- and plot-scale and within soil profiles. Results reveal (1) a relatively uniform radiocarbon signal across climatic and geologic gradients in Swiss forest topsoils (0-5 cm, Δ14C=159±36.4, n=12 sites), (2) similar radiocarbon trends with soil depth despite dissimilar environmental conditions, and (3) micro-topography dependent, plot-scale variability that is similar in magnitude to regional-scale variability (e.g., Gleysol, 0-5 cm, Δ14C 126±35.2, n=8 adjacent plots of 10x10m). Statistical analyses have additionally shown that Δ14C signature in the topsoil is not significantly correlated to climatic parameters (precipitation, elevation, primary production) except mean annual temperature at 0-5 cm. These observations have important consequences for SOM carbon stability modelling assumptions, as well as for the understanding of controls on past and current soil carbon dynamics.

scholarly journals Abordagem de multiescalas como estratégia de análise ambiental em Microbacias Hidrográficas (A multi-scale approach as a strategy for environmental analysis of hydrographic microbasins)

2016 ◽  
Vol 9 (6) ◽  
pp. 2003
Author(s):  
Andréia Dias De Medeiros ◽  
Diógenes Félix da Silva Costa ◽  
Eduardo Rodrigues Viana De Lima ◽  
Alisson Oliveira
Keyword(s):  
Land Use ◽  
Comparative Analysis ◽  
Environmental Analysis ◽  
Vegetation Cover ◽  
Landscape Analysis ◽  
Surrounding Area ◽  
Multi Scale ◽  
Mapping Strategy ◽  
Land Use And Cover

Este trabalho consiste na análise da paisagem em uma microbacia situada no Núcleo de Desertificação do Seridó, a partir de uma estratégia de mapeamento com base em uma abordagem de multiescalas. A referida abordagem teve como parâmetro de análise o uso e ocupação do solo, através de duas escalas de análise: microbacia e zona do entorno do maior reservatório da microbacia. Verificou-se que a classe Caatinga Arbustiva foi a predominante da área total da microbacia. A partir destes dados, realizou-se uma análise comparativa apenas do uso e cobertura da terra no entorno do reservatório principal, onde foi identificada como predominante a classe Caatinga Arbustiva Aberta. Evidenciou-se que mesmo não ocorrendo na microbacia um uso antrópico intensivo (retirada na cobertura vegetal), o entorno do principal reservatório apresenta um elevado percentual de cobertura pelas classes Caatinga Arbustiva Aberta, Caatinga Herbácea/Cultivo Temporário e Solo Exposto, as quais representam áreas degradadas que foram desmatadas em anos anteriores para a formação de pasto e/ou cultivo temporário. Palavras-chave: Semiárido, Desertificação, Microbacia, Análise da paisagem, SIG.   A B S T R A C T This work is a landscape analysis of a microbasin in the Núcleo de Desertificação do Seridó and used a mapping strategy based on a multi-scale approach. The approach used land use and cover as the analysis parameter and two scales: the microbasin and the larger surrounding reservoir of the microbasin. The Shrubby Caatinga class was verified as being predominant throughout the microbasin. Based on the data collected, a comparative analysis was made of land use and cover surrounding the principal reservoir, which was identified as being predominantly the Open Shrubby Caatinga class. It was evident that even though intense anthropogenic use (removal of vegetation cover) has not occurred in the microbasin, the surrounding area of the principal reservoir has a high percentage of the Open Shrubby Caatinga, Herbaceous/Temporary Cultivation Caatinga and Exposed Soil classes, which are degraded areas that were cleared during previous years to create pastures and/or areas for temporary cultivation. Keywords: Semiarid, Desertification, Microbasin, Landscape analysis, GIS   

scholarly journals Vegetation structure and greenness in Central Africa from Modis multi-temporal data

2013 ◽  
Vol 368 (1625) ◽  
pp. 20120309 ◽  
Author(s):  
Valéry Gond ◽  
Adeline Fayolle ◽  
Alexandre Pennec ◽  
Guillaume Cornu ◽  
Philippe Mayaux ◽  
...  
Keyword(s):  
Vegetation Index ◽  
Community Dynamics ◽  
Regional Scale ◽  
Congo Basin ◽  
Deciduous Forests ◽  
Environmental Drivers ◽  
Vegetation Types ◽  
Forest Types ◽  
Evergreen Forests ◽  
Multi Temporal

African forests within the Congo Basin are generally mapped at a regional scale as broad-leaved evergreen forests, with the main distinction being between terra-firme and swamp forest types. At the same time, commercial forest inventories, as well as national maps, have highlighted a strong spatial heterogeneity of forest types. A detailed vegetation map generated using consistent methods is needed to inform decision makers about spatial forest organization and their relationships with environmental drivers in the context of global change. We propose a multi-temporal remotely sensed data approach to characterize vegetation types using vegetation index annual profiles. The classifications identified 22 vegetation types (six savannas, two swamp forests, 14 forest types) improving existing vegetation maps. Among forest types, we showed strong variations in stand structure and deciduousness, identifying (i) two blocks of dense evergreen forests located in the western part of the study area and in the central part on sandy soils; (ii) semi-deciduous forests are located in the Sangha River interval which has experienced past fragmentation and human activities. For all vegetation types enhanced vegetation index profiles were highly seasonal and strongly correlated to rainfall and to a lesser extent, to light regimes. These results are of importance to predict spatial variations of carbon stocks and fluxes, because evergreen/deciduous forests (i) have contrasted annual dynamics of photosynthetic activity and foliar water content and (ii) differ in community dynamics and ecosystem processes.

scholarly journals The Joint Effects of Precipitation Gradient and Afforestation on Soil Moisture across the Loess Plateau of China

Forests ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 285 ◽  
Author(s):  
Qindi Zhang ◽  
Wei Wei ◽  
Liding Chen ◽  
Lei Yang
Keyword(s):  
Soil Moisture ◽  
Loess Plateau ◽  
Regional Scale ◽  
Mean Annual Precipitation ◽  
Precipitation Gradient ◽  
Vegetation Types ◽  
The Loess Plateau ◽  
Deep Soil ◽  
Ecological Regions ◽  
Caragana Korshinskii

Understanding the dependence of soil moisture changes following afforestation on the precipitation gradient and afforested vegetation types is crucial for improving ongoing afforestation projects, and to guide future restoration strategies in water-limited regions. For this study, we characterized afforestation-induced changes in soil moisture at depths of 0–3.0 m across a precipitation gradient in the semi-arid Loess Plateau of China. A paired experiment was conducted across 15 sites, where native grasslands served as the baseline hydrology. The results showed that korshinsk peashrub (Caragana korshinskii Kom.), sea buckthorn (Hippophae rhamnoides L.), and black locust (Robinia pseudoacacia L.) afforestation caused an overall strong decline in soil moisture content at depths of below 2.2 m. The degree of soil moisture decline at the regional scale did not vary between different afforested vegetation types but was contingent on precipitation. With decreasing precipitation gradients, afforestation increased the cost of deep soil moisture. Precipitation restrictions began to appear at mean annual precipitation (MAP) = 520 mm, and were intensified at MAP = 380 mm, which could be employed to divide the Loess Plateau into different ecological regions. Because of this, different strategies should be assigned in future restoration practices to these ecological regions to align with localized precipitation conditions. It will likely be prudent to encourage afforestation in areas with MAP of more than 520 mm, while advocating alternative grassland restoration in areas with MAP of less than 380 mm.

scholarly journals Variability in <sup>14</sup>C contents of soil organic matter at the plot and regional scale across climatic and geologic gradients

2016 ◽  
Vol 13 (11) ◽  
pp. 3427-3439 ◽  
Author(s):  
Tessa Sophia van der Voort ◽  
Frank Hagedorn ◽  
Cameron McIntyre ◽  
Claudia Zell ◽  
Lorenz Walthert ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Soil Depth ◽  
Regional Scale ◽  
Mean Annual Temperature ◽  
Spatial And Temporal Variability ◽  
Climatic Parameters ◽  
Soil Systems ◽  
Modelling Assumptions ◽  
Micro Topography

Abstract. Soil organic matter (SOM) forms the largest terrestrial pool of carbon outside of sedimentary rocks. Radiocarbon is a powerful tool for assessing soil organic matter dynamics. However, due to the nature of the measurement, extensive 14C studies of soil systems remain relatively rare. In particular, information on the extent of spatial and temporal variability in 14C contents of soils is limited, yet this information is crucial for establishing the range of baseline properties and for detecting potential modifications to the SOM pool. This study describes a comprehensive approach to explore heterogeneity in bulk SOM 14C in Swiss forest soils that encompass diverse landscapes and climates. We examine spatial variability in soil organic carbon (SOC) 14C, SOC content and C : N ratios over both regional climatic and geologic gradients, on the watershed- and plot-scale and within soil profiles. Results reveal (1) a relatively uniform radiocarbon signal across climatic and geologic gradients in Swiss forest topsoils (0–5 cm, Δ14C  =  130 ± 28.6, n = 12 sites), (2) similar radiocarbon trends with soil depth despite dissimilar environmental conditions, and (3) micro-topography dependent, plot-scale variability that is similar in magnitude to regional-scale variability (e.g., Gleysol, 0–5 cm, Δ14C 126 ± 35.2, n = 8 adjacent plots of 10  ×  10 m). Statistical analyses have additionally shown that Δ14C signature in the topsoil is not significantly correlated to climatic parameters (precipitation, elevation, primary production) except mean annual temperature at 0–5 cm. These observations have important consequences for SOM carbon stability modelling assumptions, as well as for the understanding of controls on past and current soil carbon dynamics.

scholarly journals Ecosystem-Dependent Responses of Vegetation Coverage on the Tibetan Plateau to Climate Factors and Their Lag Periods

2021 ◽  
Vol 10 (6) ◽  
pp. 394
Author(s):  
Shuohao Cai ◽  
Xiaoning Song ◽  
Ronghai Hu ◽  
Da Guo
Keyword(s):  
Tibetan Plateau ◽  
Growing Season ◽  
Vegetation Coverage ◽  
Evergreen Forest ◽  
The Tibetan Plateau ◽  
Climate Factors ◽  
Vegetation Types ◽  
Climatic Parameters ◽  
Lag Effects ◽  
Temperate Desert

The spatiotemporal variation characteristics of the Normalized Difference Vegetation Index (NDVI) and its climate response patterns are of significance in deepening our understanding of regional vegetation and climate change. The response of vegetation to climate factors varies spatially and may have lag periods. In this paper, we studied the spatiotemporal responses of vegetation to climatic factors on an ecosystem-dependent scale using GIMMS NDVI3g data and climatic parameters. Pure pixels with a single vegetation type were firstly extracted to reduce the influence of mixed vegetation types. Then, a lag correlation analysis was used to explore the lag effects of climatic parameters affecting NDVI. Finally, the stepwise regression method was adopted to calculate the regression equation for NDVI and meteorological data with the consideration of effect lag times. The results show that precipitation has significant lag effects on vegetation. Temperature is the main climatic factor that affects most vegetation types at the start of growing season. At the end of growing season, the temperate desert, temperate steppe, and temperate desert steppe are greatly affected by precipitation. Moreover, the alpine steppe, alpine desert, alpine meadow, and alpine sparse vegetation are greatly affected by temperature. The needleleaf forest, subalpine scrub, and broadleaf evergreen forest are sensitive to sunshine percentage during almost the whole growing season. These findings could contribute to a better understanding of the drivers and mechanisms of vegetation degradation on the Tibetan Plateau.

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