Vegetation dynamics in response to human and climatic factors in the Tanzanian Coast

The interactive effects of climatic factors (precipitation and temperature) on vegetation growth can be characterized by their effect on vegetation seasonal dynamics. The interactive effects, seasonal trend of vegetation growth, and its future consistency (potential for future trend) have not been adequately studied in the literature. In this work, using the Enhanced Vegetation Index (EVI) and gridded climate data at a resolution of 250 m in the central Loess Plateau region, we examined seasonal vegetation dynamics with climate changes and the interactive effects of climatic factors on vegetation growth at the pixel and regional scales from the period 2000 to 2015. Vegetation cover in the Central Loess Plateau in China has dramatically changed due to the Grain-for-Green (GFG) ecological restoration program, which was designed to convert cropland to forestland or grassland since 1999. Our results show that the EVI increased significantly during the 16 year period and is likely to continue to increase in the near future. Relatively small Hurst exponents for forestland suggests that the potential for a future increased trend will be weak for the forest. Large Hurst exponents for grassland indicate its strong potential of further increase. Significant increases in spring precipitation have promoted vegetation growth, while significant decreases in summer temperature have had negative effects on vegetation growth. For temperatures between 10 to 20 °C, the impact of temperature on vegetation growth has a clear positive relationship with the moderator variable precipitation. For precipitation < 200 mm in the growing season, the impact of precipitation on vegetation growth has a clearly positive relationship with the moderator variable temperature. Results of this study will provide useful and important guidelines for designing forestland and grassland restoration plans in arid, semiarid and sub-humid regions.

Download Full-text

Morphological and Chemical Traits of Cladonia Respond to Multiple Environmental Factors in Acidic Dry Grasslands

Microorganisms ◽

10.3390/microorganisms9020453 ◽

2021 ◽

Vol 9 (2) ◽

pp. 453

Author(s):

Gabriele Gheza ◽

Luca Di Nuzzo ◽

Chiara Vallese ◽

Matteo Barcella ◽

Renato Benesperi ◽

...

Keyword(s):

Environmental Factors ◽

Vegetation Dynamics ◽

Climatic Factors ◽

Biotic Interactions ◽

Dry Grasslands ◽

Reproduction Strategies ◽

Colonization Patterns ◽

Chemical Traits ◽

Substrate Ph ◽

Terricolous Lichen

Terricolous lichen communities in lowlands occur especially in open dry habitats. Such communities are often dominated by species of the genus Cladonia, which are very variable in morphology, reproduction strategies, and secondary metabolites. In this work, we investigated traits-environment relationships considering vegetation dynamics, substrate pH, disturbance, and climate. A total of 122 plots were surveyed in 41 acidic dry grasslands in the western Po Plain (Northern Italy). Relationships between Cladonia traits and environmental variables were investigated by means of a model-based Fourth Corner Analysis. Thallus morphology and metabolites responded to vegetation dynamics, substrate pH, disturbance, and climate, whereas reproduction strategies responded only to vegetation dynamics. Traits’ correlations with vegetation dynamics elucidate their colonization patterns in open dry habitats or suggest biotic interactions with bryophytes and vascular plants. In addition, correlations between metabolites and environmental factors support interpretations of their ecological roles. Our results also stress the importance of studying traits’ relationships with climatic factors as an alert towards lichen reactions to climate change.

Download Full-text

Climatic Constraints to Monthly Vegetation Dynamics in Desert Areas Over the Silk Road Economic Belt

Remote Sensing ◽

10.3390/rs13050995 ◽

2021 ◽

Vol 13 (5) ◽

pp. 995

Author(s):

Yu-Jun Ma ◽

Fang-Zhong Shi ◽

Xia Hu ◽

Xiao-Yan Li

Keyword(s):

Vegetation Dynamics ◽

Climatic Factors ◽

Climatic Conditions ◽

Silk Road ◽

Arid Areas ◽

Accumulation Effect ◽

Silk Road Economic Belt ◽

Dryland Ecosystems ◽

Desert Areas ◽

The Silk Road

The sustainability of vulnerable eco-environment over the Silk Road Economic Belt is under threat of climate change, and the identification of vegetation constraints by sub-optimum climatic conditions is critically essential to maintain existing dryland ecosystems. To better understand how the vegetation varies at monthly scale and its effect by climate conditions in different desert areas, this study first investigated the seasonal variation of the normalized difference vegetation index (NDVI). Then, we analyzed the time effects of diverse climatic factors (air temperature, solar radiation, precipitation) on NDVI and estimated the limitation of NDVI by these climatic factors in different desert areas. The result showed that the mean monthly NDVI during 1982–2015 showed a unimodal variation in most desert areas, with high values in late spring and summer over cold arid areas, in early spring or early autumn over hot arid areas, and in summer over polar areas, respectively. Solar radiation and precipitation in cold arid areas presented 1–2 month lag or accumulation effect on NDVI, while precipitation in most hot arid areas showed no remarkable time-lag but 3 month accumulation effect, and all three climate factors in polar areas exhibited 1–3 month accumulation effect. The explanatory power of climatic conditions for vegetation dynamics considering time effects increased by 3.4, 10.8, and 5.9% for the cold arid areas, hot arid areas, and polar areas (i.e., relative increase of 4.1, 25.4, and 8.2%), respectively. The main climatic constraints to vegetation dynamics were the water condition in hot arid areas (>78%) and the temperature condition in polar areas (>67%), while cold arid areas were simultaneously limited by the water and temperature conditions (>76% in total). These results provide a detailed understanding of vegetation variation and ecological projection, which are very important to implement adaption measures for dryland ecosystems over the Silk Road Economic Belt.

Download Full-text

The Effects of Climatic Factors on Vegetation Dynamics of Tallgrass and Shortgrass Cover

Geocarto International ◽

10.1080/10106040008542161 ◽

2000 ◽

Vol 15 (3) ◽

pp. 33-38 ◽

Cited By ~ 20

Author(s):

Bradley C. Rundquist ◽

John A. Harrington

Keyword(s):

Vegetation Dynamics ◽

Climatic Factors

Download Full-text

Vegetation dynamics and its relationship with climatic factors in the Changbai Mountain Natural Reserve

Journal of Mountain Science ◽

10.1007/s11629-011-2206-4 ◽

2011 ◽

Vol 8 (6) ◽

pp. 865-875 ◽

Cited By ~ 13

Author(s):

Guanglei Hou ◽

Hongyan Zhang ◽

Yeqiao Wang

Keyword(s):

Vegetation Dynamics ◽

Climatic Factors ◽

Changbai Mountain ◽

Natural Reserve

Download Full-text

Spatiotemporal variation of vegetation dynamics and correlations with climatic factors in the Tibetan Plateau, China

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/346/1/012015 ◽

2019 ◽

Vol 346 ◽

pp. 012015 ◽

Cited By ~ 1

Author(s):

Q L Fang ◽

L X Zhou ◽

L P Zhu ◽

X J Zhang ◽

J Yang ◽

...

Keyword(s):

Tibetan Plateau ◽

Vegetation Dynamics ◽

Climatic Factors ◽

Spatiotemporal Variation ◽

The Tibetan Plateau

Download Full-text

A Forecast Model Applied to Monitor Crops Dynamics Using Vegetation Indices (NDVI)

Applied Sciences ◽

10.3390/app11041859 ◽

2021 ◽

Vol 11 (4) ◽

pp. 1859

Author(s):

Francisco Carreño-Conde ◽

Ana Elizabeth Sipols ◽

Clara Simón de Blas ◽

David Mostaza-Colado

Keyword(s):

Remote Sensing ◽

Time Series ◽

Vegetation Dynamics ◽

Environmental Changes ◽

Multiple Scales ◽

Climatic Factors ◽

Vegetation Indices ◽

Arid Zones ◽

Electromagnetic Spectrum ◽

Combination Of Forecasts

Vegetation dynamics is very sensitive to environmental changes, particularly in arid zones where climate change is more prominent. Therefore, it is very important to investigate the response of this dynamics to those changes and understand its evolution according to different climatic factors. Remote sensing techniques provide an effective system to monitor vegetation dynamics on multiple scales using vegetation indices (VI), calculated from remote sensing reflectance measurements in the visible and infrared regions of the electromagnetic spectrum. In this study, we use the normalized difference vegetation index (NDVI), provided from the MOD13Q1 V006 at 250 m spatial resolution product derived from the MODIS sensor. NDVI is frequent in studies related to vegetation mapping, crop state indicator, biomass estimator, drought monitoring and evapotranspiration. In this paper, we use a combination of forecasts to perform time series models and predict NDVI time series derived from optical remote sensing data. The proposed ensemble is constructed using forecasting models based on time series analysis, such as Double Exponential Smoothing and autoregressive integrated moving average with explanatory variables for a better prediction performance. The method is validated using different maize plots and one olive plot. The results after combining different models show the positive influence of several weather measures, namely, temperature, precipitation, humidity and radiation.

Download Full-text