scholarly journals Climate effects on vegetation vitality at the treeline of boreal forests of Mongolia

2018 ◽  
Vol 15 (5) ◽  
pp. 1319-1333 ◽  
Author(s):  
Michael Klinge ◽  
Choimaa Dulamsuren ◽  
Stefan Erasmi ◽  
Dirk Nikolaus Karger ◽  
Markus Hauck
Keyword(s):  
Climate Change ◽  
Boreal Forest ◽  
Human Impact ◽  
Forest Type ◽  
Forest Steppe ◽  
Paleoenvironmental Reconstruction ◽  
Climate Data ◽  
Southern Boundary ◽  
The Mean ◽  
Limiting Parameters

Abstract. In northern Mongolia, at the southern boundary of the Siberian boreal forest belt, the distribution of steppe and forest is generally linked to climate and topography, making this region highly sensitive to climate change and human impact. Detailed investigations on the limiting parameters of forest and steppe in different biomes provide necessary information for paleoenvironmental reconstruction and prognosis of potential landscape change. In this study, remote sensing data and gridded climate data were analyzed in order to identify main distribution patterns of forest and steppe in Mongolia and to detect environmental factors driving forest development. Forest distribution and vegetation vitality derived from the normalized differentiated vegetation index (NDVI) were investigated for the three types of boreal forest present in Mongolia (taiga, subtaiga and forest–steppe), which cover a total area of 73 818 km2. In addition to the forest type areas, the analysis focused on subunits of forest and nonforested areas at the upper and lower treeline, which represent ecological borders between vegetation types. Climate and NDVI data were analyzed for a reference period of 15 years from 1999 to 2013. The presented approach for treeline delineation by identifying representative sites mostly bridges local forest disturbances like fire or tree cutting. Moreover, this procedure provides a valuable tool to distinguish the potential forested area. The upper treeline generally rises from 1800 m above sea level (a.s.l.) in the northeast to 2700 m a.s.l. in the south. The lower treeline locally emerges at 1000 m a.s.l. in the northern taiga and rises southward to 2500 m a.s.l. The latitudinal gradient of both treelines turns into a longitudinal one on the eastern flank of mountain ranges due to higher aridity caused by rain-shadow effects. Less productive trees in terms of NDVI were identified at both the upper and lower treeline in relation to the respective total boreal forest type area. The mean growing season temperature (MGST) of 7.9–8.9 ∘C and a minimum MGST of 6 ∘C are limiting parameters at the upper treeline but are negligible for the lower treeline. The minimum of the mean annual precipitation (MAP) of 230–290 mm yr−1 is a limiting parameter at the lower treeline but also at the upper treeline in the forest–steppe ecotone. In general, NDVI and MAP are lower in grassland, and MGST is higher compared to the corresponding boreal forest. One exception occurs at the upper treeline of the subtaiga and taiga, where the alpine vegetation consists of mountain meadow mixed with shrubs. The relation between NDVI and climate data corroborates that more precipitation and higher temperatures generally lead to higher greenness in all ecological subunits. MGST is positively correlated with MAP of the total area of forest–steppe, but this correlation turns negative in the taiga. The limiting factor in the forest–steppe is the relative humidity and in the taiga it is the snow cover distribution. The subtaiga represents an ecological transition zone of approximately 300 mm yr−1 precipitation, which occurs independently from the MGST. Since the treelines are mainly determined by climatic parameters, the rapid climate change in inner Asia will lead to a spatial relocation of tree communities, treelines and boreal forest types. However, a direct deduction of future tree vitality, forest composition and biomass trends from the recent relationships between NDVI and climate parameters is challenging. Besides human impact, it must consider bio- and geoecological issues like, for example, tree rejuvenation, temporal lag of climate adaptation and disappearing permafrost.

scholarly journals Climate effects on the vitality of boreal forests at the treeline in different ecozones of Mongolia

2017 ◽  
Author(s):  
Michael Klinge ◽  
Choimaa Dulamsuren ◽  
Stefan Erasmi ◽  
Dirk Nikolaus Karger ◽  
Markus Hauck
Keyword(s):  
Climate Change ◽  
Boreal Forest ◽  
Vegetation Index ◽  
Mean Annual Precipitation ◽  
Forest Belt ◽  
Limiting Factor ◽  
Forest Steppe ◽  
Climate Data ◽  
Southern Boundary ◽  
The Mean

Abstract. In northern Mongolia, at the southern boundary of the Siberian boreal forest belt, the distribution of steppe and forest is generally linked to climate and topography, making this region highly sensible to climate change. Detailed investigations on the limiting parameters of forest and steppe occurrence in different ecozones provide necessary information for environmental modelling and scenarios of potential landscape change. In this study, remote sensing data and gridded climate data were analyzed in order to identify distribution patterns of forest and steppe in Mongolia and to detect driving ecological factors of forest occurrence and vulnerability against environmental change. With respect to anomalies in extreme years we integrated the climate and land cover data of a 15 year period from 1999–2013. Forest distribution and vegetation vitality derived from the normalized differentiated vegetation index (NDVI) were investigated for the three ecozones with boreal forest present in Mongolia (taiga, subtaiga, and forest-steppe). In addition to the entire ecozone areas, the analysis focused on different subunits of forest and non-forested areas at the upper and lower treeline, which represent ecological borderlines of site conditions. The total cover of boreal forest in Mongolia was estimated at 73 818 km2. The upper treeline generally increases from 1800 m above sea level (a.s.l.) in the Northeast to 2700 m a.s.l. in the South. The lower treeline locally emerges at 1000 m a.s.l. in the northern taiga and is rising southward to 2500 m a.s.l. The latitudinal trend of both treelines turns into a longitudinal trend in the east of the mountains ranges due to more aridity caused by rain-shadow effects. Less vital trees were identified by NDVI at both, the upper and lower treeline in relation to the respective ecozone. The mean growing season temperature (MGST) of 7.9–8.9 °C and a minimum of 6 °C was found to be a limiting parameter at the upper treeline but negligible for the lower treeline and the total ecozones. The minimum of the mean annual precipitation (MAP) of 230–290 mm yr−1 is an important limiting factor at the lower treeline but at the upper treeline in the forest-steppe ecotone, too. In general, NDVI and MAP are lower in grassland, and MGST is higher compared to the forests in the same ecozone. An exception occurs at the upper treeline of the subtaiga and taiga, where the alpine vegetation is represented by meadow mixed with shrubs. Comparing the NDVI with climate data shows that increasing precipitation and higher temperatures generally lead to higher greenness in all ecological subunits. While the MGST is positively correlated with the MAP of the total ecozones of the forest-steppe, this correlation turns negative in the taiga ecozone. The subtaiga represents an ecological transition zone of approximately 300 mm yr−1 precipitation, which occurs independently from the MGST. Nevertheless, higher temperatures lead to higher vegetation vitality in terms of NDVI values. Climate change leads to a spatial relocation of tree communities, treelines and ecozones, thus an interpretation of future tree vitality and biomass trends directly from the recent relationships between NDVI and climate parameters is difficult. While climate plays a major role for vegetation and treeline distribution in Mongolia, the disappearing permafrost needs to be accounted for as a limiting factor for tree growth when modeling future trends of climate warming and human forest disturbance.

Responses of boreal conifers to climate fluctuations: indications from tree-ring widths and carbon isotope analyses

1998 ◽  
Vol 28 (4) ◽  
pp. 524-533 ◽  
Author(s):  
J Renée Brooks ◽  
Lawrence B Flanagan ◽  
James R Ehleringer
Keyword(s):  
Climate Change ◽  
Boreal Forest ◽  
Carbon Isotope ◽  
Tree Ring ◽  
Picea Mariana ◽  
Pinus Banksiana ◽  
Annual Growth ◽  
Climate Change Scenarios ◽  
Southern Boundary ◽  
The North

Spatial distribution and species composition of the boreal forest are expected to change under predicted climate change scenarios. Current research indicates that water limitations control the southern boundary of the central Canadian boreal forest and temperature limitations control the northern boundary. As part of Boreal Ecosystem - Atmosphere Study (BOREAS), we examined this idea by comparing annual variation in tree-ring widths and carbon isotope ratios ( delta 13C) of tree-ring cellulose with annual climatic parameters in the northern and southern boreal forest. Contrary to expectations, climate correlations with ring widths at the northern and southern sites were similar in black spruce (Picea mariana (Mill.) BSP). Annual growth was favored by cooler and wetter conditions. For jack pine (Pinus banksiana Lamb.), increased temperature and spring precipitation favored annual growth at both sites. In the north, annual growth was negatively correlated with winter precipitation. The delta 13C - climate correlations in Pinus banksiana followed current distribution theories. In the south, potential evapotranspiration explained significant annual delta 13C variation, whereas in the north, winter and growing season precipitation influenced annual delta 13C variations. Our data support the concept that moisture limits the southern range of Pinus banksiana and cold soil temperatures limit the northern extent. However, colder, wetter conditions favored growth of Picea mariana throughout its range. These observations strengthen the concept that species respond individually to climate change, not as a cohesive biome.

Relationship between seborrheic dermatitis and climate change: observational study (Preprint)

2019 ◽  
Author(s):  
Ömer Kutlu
Keyword(s):  
Climate Change ◽  
Seborrheic Dermatitis ◽  
Winter Season ◽  
Central Anatolia ◽  
High Humidity ◽  
Climate Data ◽  
Uv Index ◽  
Exact Etiology ◽  
The Mean ◽  
Health Registry

BACKGROUND The exact etiology of seborrheic dermatitis remains unclear and climate change is considered one of the possible triggering factors. OBJECTIVE The aim of this study was to investigate the correlation between seborrheic dermatitis and climate data including humidity, temperature, rainfall, atmospheric pressure, cloud, and UV index. METHODS The data were collected retrospectively from electronic health registry systems in Develi in the Central Anatolia region of Turkey, between August 2018- July 2019. The monthly seborrheic dermatitis incidence was calculated. Climate data for the relevant period were obtained. The correlation between seborrheic dermatitis incidence and climate data were analyzed. RESULTS The study included a total of 21588 patients applied to the Dermatology outpatient clinic. Seborrhoeic dermatitis was identified in 996 patients (4.61%). The mean age of the patients was 30.2±20.2 years. The seborrheic dermatitis incidence rate was highest in winter season (5.02%). There was a statistically significant positive correlation between high humidity (%), cloud (%) and seborrheic dermatitis incidence, while a negative correlation was between high temperature (°C) and seborrheic dermatitis incidence.(p<0.001, p=0.028, p=0.024, respectively) CONCLUSIONS Environmental factors such as high humidity, high cloud rate, and low temperature are important in the emergence of seborrheic dermatitis.

scholarly journals Modelled potential forest area in the forest-steppe of central Mongolia is about three times of actual forest area

2020 ◽  
Author(s):  
Michael Klinge ◽  
Choimaa Dulamsuren ◽  
Florian Schneider ◽  
Stefan Erasmi ◽  
Markus Hauck ◽  
...  
Keyword(s):  
Vegetation Index ◽  
Arid Environment ◽  
Forest Area ◽  
Forest Steppe ◽  
Forest Edges ◽  
Climate Data ◽  
Forest Stands ◽  
Tree Biomass ◽  
Central Mongolia ◽  
The Mean

Abstract. The Mongolian forest-steppe is highly sensitive to climate change and environmental impact. The intention of this study was to identify, which geoecological parameters control forest distribution and tree growth in this semi-arid environment, and to evaluate the actual and potential tree biomass. For this purpose, we applied a combination of tree biomass and soil mapping, remote sensing and climate data analysis to a study area in the northern Khangai Mountains, central Mongolia. Forests of different landscape units and site conditions generally showed minor differences in tree biomass. We found no significant correlation between tree biomass and NDVI (normalized differentiated vegetation index). Tree biomass was reduced at forest edges, in small fragmented forest stands of the steppe-dominated area, and in large forest stands, compared to all other forest units. The tree biomass of forests on slopes ranged between 25 and 380 Mg ha−1. The mean tree biomass in forests of 10–500 ha was 199–220 Mg ha−1, whereby tree biomass at the forest edges was 50–63 Mg ha−1 less than in the interior parts of the forests. The mean tree biomass of forests > 500 ha was 182 Mg ha−1, whereas that of forests

scholarly journals Climate trends in a specific Mediterranean viticultural area between 1950 and 2006

OENO One ◽  
2008 ◽  
Vol 42 (3) ◽  
pp. 113 ◽  
Author(s):  
Frédéric Laget ◽  
Jean-Luc Tondut ◽  
Alain Deloire ◽  
Mary T. Kelly
Keyword(s):  
Climate Change ◽  
Potential Evapotranspiration ◽  
Time Frame ◽  
Total Solar Radiation ◽  
Climate Data ◽  
Climatic Parameters ◽  
Climate Trends ◽  
The Past ◽  
Harvest Dates ◽  
The Mean

<p style="text-align: justify;"><strong>Aims</strong>: An analysis of climate data between 1950 and 2006 in the Hérault department, situated in the Mediterranean of France is presented.</p><p style="text-align: justify;"><strong>Methods and results</strong>: Data presented include the evolution of mean annual and seasonal temperatures, the Huglin index, total solar radiation, night freshness index, the distribution and efficiency of rainfall and potential evapotranspiration (pET). Results showed an increase in mean annual temperatures of +1.3 °C between 1980 and 2006 and an increase in the mean pET which was 900 mm / year since 1999. Also, harvest dates advanced by up to three weeks and sugar concentrations at harvest increased by up to 1.5 % potential alcohol.</p><p style="text-align: justify;"><strong>Conclusion</strong>: The indicators show that in this area certain climatic parameters have evolved over the period studied. Changes are observable in some of the parameters (notably temperature) for the last 30 years whereas others have evolved only in the past few years (e.g. pET). Therefore it is necessary to be circumspect in drawing conclusions on climate change in the area, particularly as regards the possible consequences for viticulture. However, at the plot level, it is clear that irrigation of the vines is becoming increasingly necessary in this region.</p><p style="text-align: justify;"><strong>Significance and impact of study</strong>: Climate is a major factor in vine cultivation and in the understanding of viticultural terroirs and wine typicality. The climate trends observed over a 50-year period are discussed in the viticultural context of a Mediterranean region. However, the interaction between climate change and technical progress in viticulture and oenology complicate the analysis over the time frame under consideration.</p>

scholarly journals Soil and Water Management Practices as a Strategy to Cope with Climate Change Effects in Smallholder Potato Production in the Eastern Highlands of Ethiopia

2021 ◽  
Vol 13 (11) ◽  
pp. 6420
Author(s):  
Ashenafi Woldeselassie ◽  
Nigussie Dechassa ◽  
Yibekal Alemayehu ◽  
Tamado Tana ◽  
Bobe Bedadi
Keyword(s):  
Climate Change ◽  
Soil Moisture ◽  
Soil Fertility ◽  
Potato Production ◽  
Annual Rainfall ◽  
Mineral Fertilizers ◽  
Climate Data ◽  
Supplemental Irrigation ◽  
The Mean ◽  
Eastern Highlands

Low soil fertility and climate change-induced low soil moisture are major problems constraining potato (Solanum tuberosum L.) production in the eastern highlands of Ethiopia. Climate events are projected to become more pervasive. Therefore, research was conducted with the objective of analyzing smallholder potato farmers’ adaptation strategies to cope with the issues of low soil fertility and low soil moisture that are exacerbated by climate change. The research involved surveying eight purposively selected peasant associations in four major potato-producing districts in east and west Hararghe zones. The survey employed a multistage sampling procedure. Data were collected from 357 households using a standard questionnaire, focus group discussions, and key informant interviews. The data were analyzed using descriptive statistics, index ranking, and analysis of variance for survey data. The observed climate data for the period of 1988 to 2017 were analyzed. The Mann-Kendall trend test, standard anomaly index, precipitation concentration index, and coefficient of variation were used to analyze the observed climate data. The survey results revealed the farmers, on average, applied 159 kg urea, 165 kg NPS (63 kg P2O5, 31 kg N and 12 kg S), and 1.8 ton of farmyard manure per hectare for producing potatoes. Most smallholder farmers (68.91%) used supplemental irrigation for potato production during the main growing season. The method of irrigation the farmers used was overwhelmingly the furrow method (92.72%). Analyzing the climate data showed that the mean annual temperature increased whereas the mean annual rainfall decreased during the 30-year period. It was concluded that climate change is markedly affecting potato production; in response to this, most of the farmers used supplemental irrigation to cope with moisture stress, all of them applied mineral fertilizers, and some of them additionally applied organic fertilizer to alleviate the problems of soil degradation and nutrient depletion. This implies that soil moisture and nutrient stresses are the major problems constraining potato production against which the farmers need policy and institutional supports to consolidate their coping strategies and build resilience against climate change.

scholarly journals Application of SWAT in Hydrological Simulation of Complex Mountainous River Basin (Part II: Climate Change Impact Assessment)

Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1548
Author(s):  
Suresh Marahatta ◽  
Deepak Aryal ◽  
Laxmi Prasad Devkota ◽  
Utsav Bhattarai ◽  
Dibesh Shrestha
Keyword(s):  
Climate Change ◽  
River Basin ◽  
Climate Models ◽  
Assessment Tool ◽  
Swat Model ◽  
Global Climate Models ◽  
Climate Data ◽  
The Future ◽  
The Impact ◽  
Mountainous River

This study aims at analysing the impact of climate change (CC) on the river hydrology of a complex mountainous river basin—the Budhigandaki River Basin (BRB)—using the Soil and Water Assessment Tool (SWAT) hydrological model that was calibrated and validated in Part I of this research. A relatively new approach of selecting global climate models (GCMs) for each of the two selected RCPs, 4.5 (stabilization scenario) and 8.5 (high emission scenario), representing four extreme cases (warm-wet, cold-wet, warm-dry, and cold-dry conditions), was applied. Future climate data was bias corrected using a quantile mapping method. The bias-corrected GCM data were forced into the SWAT model one at a time to simulate the future flows of BRB for three 30-year time windows: Immediate Future (2021–2050), Mid Future (2046–2075), and Far Future (2070–2099). The projected flows were compared with the corresponding monthly, seasonal, annual, and fractional differences of extreme flows of the simulated baseline period (1983–2012). The results showed that future long-term average annual flows are expected to increase in all climatic conditions for both RCPs compared to the baseline. The range of predicted changes in future monthly, seasonal, and annual flows shows high uncertainty. The comparative frequency analysis of the annual one-day-maximum and -minimum flows shows increased high flows and decreased low flows in the future. These results imply the necessity for design modifications in hydraulic structures as well as the preference of storage over run-of-river water resources development projects in the study basin from the perspective of climate resilience.

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