Striga asiatica (witch weed).

2021 ◽  
Author(s):  
Chris Parker
Keyword(s):  
Global Warming ◽  
Plant Species ◽  
Natural Vegetation ◽  
Cereal Crops ◽  
Climatic Data ◽  
Striga Asiatica ◽  
Parasitic Weeds ◽  
Crop Land ◽  
Almost All

Abstract S. asiatica is a hemiparasitic plant, native to Africa and Asia. In common with most other parasitic weeds, it is not especially invasive in natural vegetation, but is much feared in crop land where infestations can build up to ruinous levels, especially with repeated growing of susceptible cereal crops. For this reason it is included in almost all lists of noxious, prohibited plant species. It has recently been reported in Queensland, Australia. There is also evidence for its continuing spread and intensification within a number of countries in Africa in particular in rice in Tanzania and maize in Malawi. A study by Mohamed et al. (2006) suggests that on the basis of climatic data, there are many territories into which Striga species, including S. asiatica, could be introduced and thrive. Global warming could further increase this potential.

scholarly journals Modeling of climatic factors of vegetation altitudinal zonality in Ukrainian Carpathians and its future changes due to global warming

2019 ◽  
Vol 53 ◽  
pp. 240-251
Author(s):  
Alexander Mkrtchian
Keyword(s):  
Global Warming ◽  
High Altitude ◽  
Climatic Factors ◽  
Vegetation Type ◽  
System Modeling ◽  
Remote Sensing Data ◽  
Natural Vegetation ◽  
Anthropogenic Activity ◽  
Landsat 8 ◽  
Climatic Data

Prospective climate changes in the current century will cause substantial shifts in the potential species habitats, in the spatial extents of communities and ecosystems, and in the areas covered by them. The present study is related to the climatic factors influencing the formation of altitude vegetation zonality in the Ukrainian Carpathians. As the borders between altitudinal belts in this area have been substantially transformed by anthropogenic activity, the method has been elaborated for the detection of the locations of natural borders, on the basis of the statistical analysis of the distribution of the altitudinal gradient of NDVI index derived from Landsat 8 remote sensing data. Thereafter the relations between the locations of these natural borders and the WorldClim bioclimatic surfaces were analyzed by means of multiple regression models. Thus, it was revealed that the location of the boundary between nemoral and boreal altitude belts in this region is influenced mostly by minimal winter temperatures, while the location of the boundary between boreal and high-altitude treeless belts is mostly determined by the average temperatures of the warmest quarter of the year. On the basis of climatic data, the location of altitude zones of natural vegetation has been mapped, that mirror the climatic aspect of the site – the potential natural vegetation on the classification level of biome (vegetation type). WorldClim dataset, together with actual climatic data contains the prospective climatic surfaces obtained by global climatic system modeling. Using these data allowed forecasting the changes in location and relative areas of altitude belts in the Carpathians under the influence of global warming. In the middle of this century, the areas of nemoral belts are expected to expand while the areas of boreal and high-altitude treeless belts will significantly dwindle. These two belts can totally disappear in this region by 2070. Key words: Carpathians, altitude zonality, global warming, Landsat, WorldClim.

Sulphur in Northern Nigerian Soils: 1. The effects of cultivation and fertilizers on total S and sulphate patterns in soil profiles

1972 ◽  
Vol 78 (3) ◽  
pp. 465-470 ◽  
Author(s):  
A. R. Bromfield
Keyword(s):  
Crop Yields ◽  
Farmyard Manure ◽  
Natural Vegetation ◽  
Soil Profiles ◽  
Organic S ◽  
Nigerian Soils ◽  
Natural Fallow ◽  
Crop Root ◽  
Almost All ◽  
Savannah Zone

SUMMARYOrganic-S and sulphate-S were measured in the Northern Guinea savannah zone down soil profiles under undisturbed natural vegetation, and in land cleared and cropped, with and without fertilizers and farmyard manure. The main soil type was a drained, red to red-brown, sandy clay to clay loam (pH 4·1–5·6 in 0·01 M-Cal2), which strongly sorbed sulphate.Organic-S was most in the surface layers and decreased with depth. Root remains from the natural fallow vegetation, present up to 9 years after clearance, strongly influenced the distribution of organic-S. The roots disappeared after 19 years, when distribution of organic-S mainly reflected crop-root distribution; amounts of organic-S were related to crop yields. FYM was less effective in maintaining organic-S than fertilizers containing P and N.Profiles under natural vegetation contained little sulphate-S but it accumulated in the sub-soil after clearance when S was not removed. The sulphate pattern of profiles under unfertilized crops resembled that under natural vegetation. All fertilized sites had a well-defined sulphate sorbtion pattern, the deepest maximum was at 50 cm on a plot where more than 800 kg S/ha had been applied in nineteen annual aounts. Sulphate-S ranged from > 1 ppm, in the deepest samples, to 52 ppm at the absorption maximum.Almost all the sulphur applied was in the profiles or removed in harvested crops, showing that losses from erosion and leaching were small.

scholarly journals Robust increase of Indian monsoon rainfall and its variability under future warming in CMIP-6 models

2020 ◽  
Author(s):  
Anja Katzenberger ◽  
Jacob Schewe ◽  
Julia Pongratz ◽  
Anders Levermann
Keyword(s):  
Climate Change ◽  
Global Warming ◽  
Climate Models ◽  
Monsoon Rainfall ◽  
Global Climate ◽  
Coupled Model ◽  
Global Climate Models ◽  
Future Climate Change ◽  
Global Mean Temperature ◽  
Almost All

Abstract. The Indian summer monsoon is an integral part of the global climate system. As its seasonal rainfall plays a crucial role in India's agriculture and shapes many other aspects of life, it affects the livelihood of a fifth of the world's population. It is therefore highly relevant to assess its change under potential future climate change. Global climate models within the Coupled Model Intercomparison Project Phase 5 (CMIP-5) indicated a consistent increase in monsoon rainfall and its variability under global warming. Since the range of the results of CMIP-5 was still large and the confidence in the models was limited due to partly poor representation of observed rainfall, the updates within the latest generation of climate models in CMIP-6 are of interest. Here, we analyse 32 models of the latest CMIP-6 exercise with regard to their annual mean monsoon rainfall and its variability. All of these models show a substantial increase in June-to-September (JJAS) mean rainfall under unabated climate change (SSP5-8.5) and most do also for the other three Shared Socioeconomic Pathways analyzed (SSP1-2.6, SSP2-4.5, SSP3-7.0). Moreover, the simulation ensemble indicates a linear dependence of rainfall on global mean temperature with high agreement between the models and independent of the SSP; the multi-model mean for JJAS projects an increase of 0.33 mm/day and 5.3 % per degree of global warming. This is significantly higher than in the CMIP-5 projections. Most models project that the increase will contribute to the precipitation especially in the Himalaya region and to the northeast of the Bay of Bengal, as well as the west coast of India. Interannual variability is found to be increasing in the higher-warming scenarios by almost all models. The CMIP-6 simulations largely confirm the findings from CMIP-5 models, but show an increased robustness across models with reduced uncertainties and updated magnitudes towards a stronger increase in monsoon rainfall.

scholarly journals Ecological Impacts of Megaprojects: Species Succession and Functional Composition

Plants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2411
Author(s):  
Hamada E. Ali ◽  
Solveig Franziska Bucher
Keyword(s):  
Plant Species ◽  
Large Scale ◽  
Invasive Plant ◽  
Species Traits ◽  
Natural Vegetation ◽  
Ecological Impacts ◽  
Imperata Cylindrica ◽  
Dry Matter Content ◽  
Large Scale Disturbance ◽  
The Impact

Land-use changes have huge impacts on natural vegetation, especially megaprojects, as the vegetation layer is destroyed in the course of construction works affecting the plant community composition and functionality. This large-scale disturbance might be a gateway for the establishment of invasive plant species, which can outcompete the natural flora. In contrast, species occurring in the area before the construction are not able to re-establish. In this study, we analyzed the impact of a pipeline construction on a wetland nature reserve located in northern Egypt. Therefore, we analyzed the plant species occurrence and abundance and measured each plant species’ traits before the construction in 2017 as well as on multiple occasions up to 2 years after the construction had finished on altogether five sampling events. We found that the construction activity led to the establishment of an invasive species which previously did not occur in the area, namely, Imperata cylindrica, whereas five species (Ipomoea carnea, Pluchea dioscoridis, Polygonum equisetiforme, Tamarix nilotica, and Typha domingensis) could not re-establish after the disturbance. The functionality of ecosystems assessed via the analysis of plant functional traits (plant height, specific leaf area, and leaf dry matter content) changed within species over all sampling events and within the community showing a tendency to approximate pre-construction values. Functional dispersion and Rao’s quadratic diversity were higher after the megaproject than before. These findings are important to capture possible re-establishment and recovery of natural vegetation after construction and raise awareness to the impact of megaprojects, especially in areas which are high priority for conservation.

scholarly journals Species ethnobotanical values rather than regional species pool determine plant diversity in agroforestry systems

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Daniel K. N’Woueni ◽  
Orou G. Gaoue
Keyword(s):  
Species Diversity ◽  
Plant Species ◽  
Plant Diversity ◽  
Agroforestry Systems ◽  
Natural Vegetation ◽  
Species Pool ◽  
Higher Plant ◽  
Natural Habitats ◽  
Natural Systems ◽  
Regional Species Pool

AbstractThe conversion of natural systems into farms and agroecosystems is the main cause of biodiversity loss. In human-dominated landscapes, understanding the interactions between agroforestry systems and adjacent natural vegetation is fundamental to developing sustainable agricultural systems. Species can move between these two systems with natural systems providing the regional pool of species that shape the agricultural values and conservation value of the agroforestry systems. We investigated the influence of neighboring natural habitats on traditional agroforestry systems in the buffer zone of Pendjari Biosphere Reserve in Benin to understand the contribution of regional processes on the quality of agroforestry systems. We expected that agroforestry parklands adjacent to natural vegetation with high species diversity will also have higher plant species diversity. We found no similarity in plant species composition between agroforestry systems and adjacent natural habitats. A small proportion of species in adjacent natural habitats were found in agroforestry systems. The proportion of shared species was not significantly influenced by plant diversity in adjacent natural habitats or the distance from the agroforestry systems to the natural adjacent habitat. However, plant diversity in agroforestry systems was strongly associated with site ethnobotanical values indicating that farmers act as a supplemental but severe environmental filter of the regional species pool. Our study suggests that promoting the plantation of plants with high ethnobotanical use-value is a potentially viable strategy for sustainable agriculture and ecological restoration in Biosphere reserves.

scholarly journals Cecidomyiidae (Diptera, Insecta): richness of species and distribution in Brazil

2021 ◽  
Vol 21 (2) ◽  
Author(s):  
Valéria Cid Maia
Keyword(s):  
Plant Species ◽  
Atlantic Forest ◽  
Gall Midge ◽  
The Other ◽  
Amazon Forest ◽  
Gall Midges ◽  
Species Origin ◽  
Neotropical Species ◽  
Fauna Composition ◽  
Almost All

Abstract: Most Neotropical species of Cecidomyiidae (Diptera) have been described from Brazil, but a list of species with occurrence in the country has never been published. Little is known about their distribution and richness in the Brazilian phytogeographic domains. Additionally, a list of host plant species has never been gathered. The present study aims to fill these knowledge gaps and provides an overview of this family in Brazil. For this, data were obtained mainly from the literature, but also from the Cecidomyiidae collection of Museu Nacional and two herbaria (RB and R). Based on the site "Flora do Brasil 2020", botanical names were updated and plant species origin and distribution were verified. A total of 265 gall midge species have been recorded in Brazil, most from the Atlantic Forest (183), followed by Cerrado (60), and Amazon Forest (29). The other phytogeographic domains shelter from five to ten species. Phytophagous gall midges occur on 128 plant species of 52 families, almost all native, being 43 endemic to Brazil (21 endemic to Atlantic Forest, five to Cerrado, and one to Amazon). Although, the taxonomical knowledge is focused on the Atlantic Forest, each domain has its own fauna composition and these informations can be useful for environmental conservational purposes. About 58% of the Brazilian fauna are known only from the type-locality. In order to fill these gaps, it is necessary and important to collect in uninvestigated areas.

Aggressions of the Socio-Economic System on the Natural Capital

2017 ◽  
pp. 109-140
Author(s):  
Constanţa Popescu ◽  
Constantin Popescu ◽  
Maria Luiza Hrestic
Keyword(s):  
Global Warming ◽  
Adverse Effects ◽  
Economic System ◽  
Acid Rain ◽  
Natural Environment ◽  
Natural Capital ◽  
Marine Species ◽  
Vertebrate Species ◽  
New Beginning ◽  
Almost All

Nearly 250 million years ago, the Earth was shaken by the amplest extinction known so far, which led to the extinction of up to 96% of all the marine species, 70% of the vertebrate species, and almost all the insects. This extinction affected the whole range of biodiversity so much. Nature took almost 10 million years to recover after this event. Life was really in danger on our planet at that moment, due to the dismal conditions that were created, and the current research shows that these dire conditions continued to occur, in the natural environment, after that, triggering numerous outbreaks that occurred for five to six million years following the initial crisis, triggered by the carbon rise and the repeated shortages of oxygen, the increased warming and other such adverse effects, which, once initiated, were uncontrollable and had disastrous effects. When life returned to normal and, gradually, after several million years, a new beginning was possible, the significant elements that caused the disaster - global warming, acid rain - sound strangely familiar to us today.

scholarly journals Grapevine Responses to Heat Stress and Global Warming

Plants ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1754
Author(s):  
Xenophon Venios ◽  
Elias Korkas ◽  
Aspasia Nisiotou ◽  
Georgios Banilas
Keyword(s):  
Global Warming ◽  
Heat Stress ◽  
Regulatory Networks ◽  
High Temperature Stress ◽  
Extreme Weather Events ◽  
Wine Quality ◽  
Heat Stress Response ◽  
Average Annual Temperature ◽  
Current Century ◽  
Almost All

The potential effects of the forthcoming climate change include the rising of the average annual temperature and the accumulation of extreme weather events, like frequent and severe heatwaves, a phenomenon known as global warming. Temperature is an important environmental factor affecting almost all aspects of growth and development in plants. The grapevine (Vitis spp.) is quite sensitive to extreme temperatures. Over the current century, temperatures are projected to continue rising with negative impacts on viticulture. These consequences range from short-term effects on wine quality to long-term issues such as the suitability of certain varieties and the sustainability of viticulture in traditional wine regions. Many viticultural zones, particularly in Mediterranean climate regions, may not be suitable for growing winegrapes in the near future unless we develop heat-stress-adapted genotypes or identify and exploit stress-tolerant germplasm. Grapevines, like other plants, have developed strategies to maintain homeostasis and cope with high-temperature stress. These mechanisms include physiological adaptations and activation of signaling pathways and gene regulatory networks governing heat stress response and acquisition of thermotolerance. Here, we review the major impacts of global warming on grape phenology and viticulture and focus on the physiological and molecular responses of the grapevine to heat stress.

Causes and consequences of variation in snow incidence on the high mountains of Tasmania, 1983–2013

2017 ◽  
Vol 65 (3) ◽  
pp. 214 ◽  
Author(s):  
Jamie B. Kirkpatrick ◽  
Manuel Nunez ◽  
Kerry L. Bridle ◽  
Jared Parry ◽  
Neil Gibson
Keyword(s):  
Plant Species ◽  
Aerial Photographs ◽  
Climate Indices ◽  
Small Subset ◽  
Climatic Data ◽  
Shrub Cover ◽  
Bare Ground ◽  
Landsat Images ◽  
Decadal Scale ◽  
Warming World

Alpine plant species are considered to have a precarious near future in a warming world, especially where endemic on mountains without a nival zone. We investigated how and why snow patch vegetation and snow incidence varied over recent decades in Tasmania, Australia. Landsat images between 1983 and 2013 were used to calculate the proportion of clear days with snow visible on Mt Field. We compared average annual snow incidence on 74 Tasmanian alpine mountains for 1983–1996 with that for 1997–2013 using the small subset of Landsat runs in which most of Tasmania was clear of cloud. We related the temporal data from Mt Field to Tasmanian climatic data and climate indices to determine the predictors of change. We recorded plant species and life form cover from quadrats in transects through a snow patch on Mt Field in 1983, 2001 and 2014, and mapped decadal scale changes in boundaries and shrub cover at five other snow patches across the extent of the Tasmanian alpine areas from aerial photographs. The incidence of snow fluctuated between 1983 and 2013 at Mt Field with no overall trend. Snow incidence was less on lower elevation alpine mountains in the period 1997–2013 than in the period 1983–1996, but showed a weak opposite trend on mountains higher than 1350 m. The contrast in trends may be a consequence of the effect on lapse rates of stronger frontal winds associated with a steepening of latitudinal pressure gradients. At Mt Field, bare ground decreased, cover of cushion plants and tall shrubs increased and obligate snow patch species were persistent. The trends we observed in both vegetation and snow incidence differ markedly from those observed on mainland Australia. The increase in shrub cover and decrease in bare ground on Mt Field were unexpected, given the constancy in incidence of snow. These results may relate to ongoing recovery from a fire in the 1960s, as the shrub species that have increased are fire-sensitive, obligate seeders and there has been no indication of warming since 1983 in the climatic record for western Tasmania. There is a possibility that some Tasmanian alpine areas might act as long-term refugia from general warming.

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