DROUGHT AND RANGELAND GRASSHOPPER SPECIES DIVERSITY

1994 ◽  
Vol 126 (4) ◽  
pp. 1075-1092 ◽  
Author(s):  
W.P. Kemp ◽  
M.M. Cigliano
Keyword(s):  
Species Richness ◽  
Central Region ◽  
Resource Limitation ◽  
Extreme Drought ◽  
Severe Drought ◽  
Grasshopper Species ◽  
Drought Intensity ◽  
The North ◽  
South Central

AbstractRangeland grasshopper species richness was monitored at 10 sites in Montana, U.S.A., during 1986 through 1992, which included an extreme drought year (1988). We observed significant post-1988 drought reductions in rangeland grasshopper species richness in the eastern and south-central region of Montana where drought intensity has been increasing during the past 20 years. In the north-central region, which also experienced the 1988 drought but showed no long-term drought trend, we did not observe a post-drought reduction in overall rangeland grasshopper species richness. Thus, in terms of rangeland grasshopper species richness, the potential impact of a severe drought in a given year may depend on the timing of such an event within longer-term climatic cycles. Our findings suggest that as regional drought intensity increases temporally, there may be an increased likelihood that a single extreme drought year will not only have a profound impact on abundance but may also result in significant long-term reduction of grasshopper species richness. Our results support the hypothesis that resource limitation is a very important factor in structuring rangeland grasshopper communities in space and time.

scholarly journals Anurans of the Parque Estadual do Mirador, a remnant of Cerrado in the state of Maranhão, Northeastern Brazil

2017 ◽  
Vol 17 (4) ◽  
Author(s):  
Etielle Barroso de Andrade ◽  
Luiz Norberto Weber ◽  
José Roberto de Souza Almeida Leite
Keyword(s):  
Species Richness ◽  
Central Region ◽  
Wide Distribution ◽  
The State ◽  
Northeastern Brazil ◽  
Species Number ◽  
Sampling Effort ◽  
The South ◽  
Cerrado Biome ◽  
South Central

Abstract The Cerrado is one of the most threatened biomes in Brazil. It is estimated that much of its original vegetation has been replaced by some type of human use. This is quite worrying, mainly in the northern part where the number of wildlife inventories is insufficient and creates the false impression of low diversity in the region. The Parque Estadual do Mirador-PEM, located in the south-central region of the state of Maranhão, presents vegetation typical of the Cerrado biome and corresponds to one of 46 priority areas for conservation in the state. Herein, we describe the species richness and composition of the anurofauna from the PEM and analyze the influence of different types of vegetation in its formation. Our inventory was conducted from December 2013 to February 2015, using the active search and auditory census methods on breeding sites in different water bodies of the park. We recorded 31 anuran species belonging to five families (species number in parentheses): Leptodactylidae (14), Hylidae (12), Bufonidae (3), Microhylidae (1) and Phyllomedusidae (1). The rarefaction curve and species richness estimators indicated that the sampling effort was enough to record most of the species in the region. The richness of anurans in the PEM was higher than reported by other authors for several areas of Cerrado. Most species have a wide distribution in Brazil or are strongly associated with the Caatinga or Amazon biomes. Only about 19% are endemic to the Cerrado biome. This study is the first to inventory the anurans species of the south-central region of state of Maranhão and provides important data on amphibian communities from the northern part of the Brazilian Cerrado.

Patterns in data of extreme droughts/floods and harvest grades derived from historical documents in eastern China during 801–1910

2020 ◽  
Author(s):  
Zhixin Hao
Keyword(s):  
Crop Production ◽  
Eastern China ◽  
Regional Scale ◽  
Extreme Drought ◽  
Historical Documents ◽  
The North ◽  
Historical Factors ◽  
Extreme Flood ◽  
The Impact

<p>In China, historical documents record a large quantity of information related to climate change and grain harvest. This information can help to explore the impacts of extreme drought or flood on crop production, which can provide implications for the adaptation of agriculture to higher-probability extreme climate in the context of global warming. In this paper, reported extreme drought/flood chronologies and reconstructed grain harvest series derived from historical documents were adopted in order to investigate the association between the reported frequency of extreme drought/flood in eastern China and reconstructed poor harvests during 801–1910. The results show that extreme droughts were reported more often in 801–870, 1031–1230, 1481–1530, and 1581–1650 over the whole of eastern China. On a regional scale, extreme droughts were reported more often in 1031–1100, 1441–1490, 1601–1650, and 1831–1880 in the North China Plain, 801–870, 1031–1120, 1161–1220, and 1471–1530 in Jianghuai, and 991–1040, 1091–1150, 1171–1230, 1411–1470, and 1481–1530 in Jiangnan. The grain harvest was reconstructed to be generally poor in 801–940, 1251–1650, and 1841–1910, but the reconstructed harvests were bumper in 951–1250 and 1651–1840, approximately. During the entire period from 801 to 1910, the frequency of reporting of extreme droughts in any subregion of eastern China was significantly associated over the long term with lower reconstructed harvests. The association between reported frequency of extreme floods and reconstructed low harvests appeared to be much weaker, while reconstructed harvest was much worse when extreme drought and extreme flood in different subregions were reported in the same year. The association between reconstructed poor harvests and reported frequency of regional extreme droughts was weak during the warm epoch of 920–1300 but strong during the cold epoch of 1310–1880, which could imply that a warm climate could weaken the impact of extreme drought on poor harvests; yet other historical factors may also contribute to these different patterns extracted from the two datasets.</p>

scholarly journals Long-term warming and nitrogen fertilization affect C-, N- and P-acquiring hydrolase and oxidase activities in winter wheat monocropping soil

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Chuang Zhang ◽  
Wenxu Dong ◽  
Kiril Manevski ◽  
Wenpei Hu ◽  
Arbindra Timilsina ◽  
...  
Keyword(s):  
Agricultural Soils ◽  
C:N Ratio ◽  
Resource Limitation ◽  
N Fertilization ◽  
Organic N ◽  
Resource Limitations ◽  
The North ◽  
The Relationship ◽  
Enzyme Ratio

AbstractThe enzymatic activities and ratios are critical indicators for organic matter decomposition and provide potentially positive feedback to carbon (C) loss under global warming. For agricultural soils under climate change, the effect of long-term warming on the activities of oxidases and hydrolases targeting C, nitrogen (N) and phosphorus (P) and their ratios is unclear, as well as whether and to what extend the response is modulated by long-term fertilization. A 9-year field experiment in the North China Plain, including an untreated control, warming, N fertilization, and combined (WN) treatment plots, compared the factorial effect of warming and fertilization. Long-term warming interacted with fertilization to stimulate the highest activities of C, N, and P hydrolases. Activities of C and P hydrolase increased from 8 to 69% by N fertilization, 9 to 53% by warming, and 28 to 130% by WN treatment compared to control, whereas the activities of oxidase increased from 4 to 16% in the WN soils. Both the warming and the WN treatments significantly increased the enzymatic C:N ratio from 0.06 to 0.16 and the vector length from 0.04 to 0.12 compared to the control soil, indicating higher energy and resource limitation for the soil microorganisms. Compared to WN, the warming induced similar ratio of oxidase to C hydrolase, showing a comparable ability of different microbial communities to utilize lignin substrates. The relationship analyses showed mineralization of organic N to mediate the decomposition of lignin and enzyme ratio in the long-term warming soil, while N and P hydrolases cooperatively benefited to induce more oxidase productions in the soil subject to both warming and N fertilization. We conclude that coupled resource limitations induced microbial acclimation to long-term warming in the agricultural soils experiencing high N fertilizer inputs.

scholarly journals Evaluation of some effectiveness elements of the pig breeding industry in Bulgaria, through cluster analysis

2019 ◽  
Vol 35 (1) ◽  
pp. 25-33
Author(s):  
Ivelina Zapryanova
Keyword(s):  
Cluster Analysis ◽  
Central Region ◽  
Western Region ◽  
North Central Region ◽  
North Central ◽  
The North ◽  
South Central ◽  
North Eastern ◽  
Central Regions ◽  
North Western

An evaluation was made of the effectiveness elements of the pig breeding industry in Bulgaria in the period 2001-2016, through cluster analysis. The studied period was divided in 3 subperiods, each one with three similar groups (clusters). Through application of cluster analysis, the proximity of the different administration regions in the country was defined in accordance with certain indicators of the pig breeding effectiveness. It was found that in the first cluster for the period 2001-2006 fall North-Western and South-Western region. The North-Eastern and North-Central region form the second cluster. The South-Eastern and South-Central region fall mainly into the third cluster. In the first cluster for the period 2007-2011, the North-Western, South-Western and South-Central regions have a priority with the lowest number of sold animals. The North-Eastern and the North-Central region, forming a third cluster, remain with the highest effectiveness of the pig farming. After the end of 2013 an aggregation of the sector began. For the period 2012-2016, the second cluster is formed from three regions - North-Western, South-Western, and South-Central in 2013.

scholarly journals Long-term associations and insights on social structure of the Humpback whales in Prince William Sound, Alaska

2020 ◽  
Author(s):  
Olga von Ziegesar ◽  
Shelley Gill ◽  
Beth Goodwin
Keyword(s):  
Social Structure ◽  
Feeding Habits ◽  
North Pacific Ocean ◽  
Small Population ◽  
Population Characteristics ◽  
Humpback Whales ◽  
Prince William Sound ◽  
The North ◽  
South Central

AbstractHumpback whale (Megaptera novaeangliae) social structure is more complex than previously thought. Because of the fluid “fission-fusion” nature of their relationships: individuals foraging, traveling, and socializing with a number of animals, where associations form and are broken numerous times, little has been confirmed about their long-term associations. Humpback whales of the North Pacific Ocean migrate annually between tropical breeding areas to northern latitudes where they congregate and feed. The purpose of this study was to explore the social and feeding habits of the summer population of humpback whales returning to Prince William Sound (PWS) in the south central coast of Alaska. Fluke photographs of pigmentation patterns were used to document individual whales between the years 1983 and 2009 to determine, population characteristics, reproductive rates, long-term associations, feeding habits and spatial partitioning. During the 27 year study period there were 3,017 encounters with 405 unique whales. Forty of these whales (9.88%) had long sighting histories, showing strong site fidelity. Association indices for all pairs of whales were calculated. Long-lasting associations were found between thirty-two of the forty whales. Two distinct groups were determined by the highest association coefficients. Although the overall ranges of the two groups overlapped, they did not often mingle and offspring did not join their maternal group. All but two females had enduring bonds with at least one male. Associate males were sometimes found at a distance from others of their “clan” and would rejoin periodically. Two whales from one of these clans were found together in Hawaiian waters, a male escorting a female with a newborn calf, suggesting these long lasting associations endure through migration and into the southern breeding areas. Optimal observation conditions of a small population of humpback whales in sheltered waters allowed the discovery of two social groups enduring almost three decades.

Grasshopper (Orthoptera: Acrididea) assemblages in forests and savanna areas in Center, West and South-west regions of Cameroon

2019 ◽  
Vol 12 (1) ◽  
pp. 17-32
Author(s):  
ALAIN CHRISTEL WANDJI ◽  
SÉVILOR KEKEUNOU ◽  
MARCELLE MBADJOUN NZIKE ◽  
ALAIN SIMEU NOUTCHOUM ◽  
ABRAHAM FOMENA
Keyword(s):  
Species Richness ◽  
Vegetation Type ◽  
Forest Degradation ◽  
Dissimilarity Index ◽  
Grasshopper Species ◽  
Crop Fields ◽  
Environmental Variations ◽  
Capture Method ◽  
First Time

Forest degradation due to human activities is a major threat to the long-term persistence of many species. It affects species richness, abundance and can lead to the extinction of some species. The present work aimed at identifying the effect of environmental variations on the species richness and composition of grasshoppers in three regions Cameroon. In each region, four vegetations (forests, agroforests, fallows and crop fields) were investigated using sweep nets and pitfalls trapping for specimens’ capture from February 2016 to February 2018. From this study, 92 grasshoppers species belonging to 3 families, 13 subfamilies and 70 genera were collected. The Acrididae was the most diverse family with 77 species. The Catantopinae was the richest subfamily (22 species), while the Pterotiltus was the richest genus with 7 species. Overall, the average sample success was 92.49%. We found that the species richness was strongly influenced by the study site (region), the vegetation type, and the capture method. The dissimilarity index revealed that the grasshopper communities of West and Center region were similar to each other, like those of fallows and crop fields.  Twenty-four species of grasshopper could be reported for the first time in Cameroon. This study updates the database on the grasshopper fauna of Cameroon and brings to 238 the number of grasshopper species known in Cameroon. Key words: Grasshoppers, species richness, forests, agroforests, fallows, crop fields

Agricultural Drought in Vietnam

2005 ◽  
Author(s):  
Nguyen van Viet ◽  
Vijendra K. Boken
Keyword(s):  
Central Region ◽  
Geographical Area ◽  
River Delta ◽  
Agricultural Drought ◽  
Annual Rainfall ◽  
Delta Region ◽  
Red River Delta ◽  
The North ◽  
South Central ◽  
Central Highland

Vietnam is located between 8°22'N and 23°22'N latitude and between 102°10'E and 109°21'E longtitude. The country has a geographical area > 333,000 km2 and a coastline > 3000 km long. Vietnam is situated in the typhoon center of the East Sea (Bien Dong), which is one of the five largest typhoon centers of the world, and it has a complicated topography ranging from narrow, low plains to steep, high mountains. Floods occur with high frequency, and drought occurs with medium frequency in Vietnam. If monthly rainfall is less than 50 mm, drought is considered to have occurred during the month. The climate of Vietnam is strongly influenced by mountainous terrain and by the northeast and southeast monsoons. The rainfall season, which usually begins in May–June and ends in November–December, accounts for about 75–85% of the total annual rainfall. The period from November– December to April–May is usually dry and is prone to droughts. Vietnam has been divided into seven agricultural regions: (1) north mountain and midland region, (2) northern delta region (Red River delta), (3) north-central region, (4) south-central region, (5) central highland region (Taynguyen platour), (6) southeast region, and (7) southern delta region (Mekong River delta). The rainfall distribution is uneven due to complex terrain conditions. While some places (in the north mountain, central, and central highland regions) receive 3000–4000 mm of rainfall annually, other places (such as Phanthiet and Phanrang of the south-central region) receive only 750–800 mm in a year. Rice and maize are the major crops in Vietnam, whose regional distributions are given in table 27.1. Table 27.2 shows rice area lost due to droughts during 1980–99 in different regions of Vietnam. The north mountain and midland region is not prone to droughts. Only moderate droughts occur at some places in this region. Droughts rarely occur for consecutive years, except the droughts that occurred during the summer season of 1988 and 1989. The northeast part of this region is more prone to drought than the rest of the region.

scholarly journals Drought assessment and the impacts on the agriculture and the forestry in Slovakia in 2020

2021 ◽  
Author(s):  
Maroš Turňa ◽  
Gabriela Ivaňáková ◽  
Ivana Krčová ◽  
Ivan Mrekaj ◽  
Jakub Ridzoň
Keyword(s):  
Atmospheric Precipitation ◽  
Weather Conditions ◽  
Middle Part ◽  
Point Of View ◽  
Extreme Drought ◽  
Soil Drought ◽  
Severe Drought ◽  
Seasonal Temperature ◽  
Drought Assessment ◽  
The North

<p>Weather conditions were quite remarkable in Slovakia during the whole year of 2020. In terms of annual mean temperature, year 2020 was very warm, with temperature very much above normal and deviations ranging mostly from +1.3 to +1.6 ° C from the normal 1981-2010 (in mountain regions even more than +1.7 ° C). With the exception of spring 2020, all other seasons were significantly above normal in terms of seasonal temperature, especially the winter 2019/2020. From the point of view of the amount of atmospheric precipitation, last year has mostly the above-normal precipitation. This was mainly due to the frequent occurrence of thunderstorm torrential rainfalls during the summer and due to the exceptionally above-normal precipitation in October, when extreme widespread rainfalls occurred in some regions of western and eastern Slovakia between 11 and 15 October. The second half of the year was thus significantly different from the point of view of the precipitation balance in comparison with the period from 10 March to approximately 15 May, when exceptionally dry conditions prevailed in Slovakia. The drought in Slovakia in year 2020 was dominant mostly in the spring, mainly in April and in the beginning of May. The lack of soil moisture was caused by the very low level of the snow cover in the previous winter months and the weather was also influenced by the long-term anticyclone in April 2020. This month was very dry in the major part of Slovakia and the extreme drought hit 24.3 % of the area of Slovakia. The unfavourable situation was registered in various regions by our reporters, in both the agricultural and forestry sectors. In summer the situation was stable and the severe drought didn´t occurred. In September the mild drought was only in the eastern part of Slovakia. October was humid in several regions. The severe and extreme soil drought in November was expressed in the first half of December in the north-western and middle part of Slovakia.</p><p> Key words: extreme drought, April 2020</p>

scholarly journals Groundwater and baseflow drought responses to synthetic recharge stress tests

2021 ◽  
Vol 25 (2) ◽  
pp. 1053-1068
Author(s):  
Jost Hellwig ◽  
Michael Stoelzle ◽  
Kerstin Stahl
Keyword(s):  
Fractured Rock ◽  
Drought Severity ◽  
Severe Drought ◽  
Stress Tests ◽  
The North ◽  
Groundwater Response ◽  
Dry Spells ◽  
Groundwater Drought ◽  
Fractured Rock Aquifers

Abstract. Groundwater is the main source of freshwater and maintains streamflow during drought. Potential future groundwater and baseflow drought hazards depend on the systems' sensitivity to altered recharge conditions. We performed groundwater model experiments using three different generic stress tests to estimate the groundwater and baseflow drought sensitivity to changes in recharge. The stress tests stem from a stakeholder co-design process that specifically followed the idea of altering known drought events from the past, i.e. asking whether altered recharge could have made a particular event worse. Across Germany, groundwater responses to the stress tests are highly heterogeneous, with groundwater heads in the north more sensitive to long-term recharge and in the Central German Uplands to short-term recharge variations. Baseflow droughts are generally more sensitive to intra-annual dynamics, and baseflow responses to the stress tests are smaller compared to the groundwater heads. The groundwater drought recovery time is mainly driven by the hydrogeological conditions, with slow (fast) recovery in the porous (fractured rock) aquifers. In general, a seasonal shift of recharge (i.e. less summer recharge and more winter recharge) will have lesser effects on groundwater and baseflow drought severity. A lengthening of dry spells might cause much stronger responses, especially in regions with slow groundwater response to precipitation. Water management may need to consider the spatially different sensitivities of the groundwater system and the potential for more severe groundwater droughts in the large porous aquifers following prolonged meteorological droughts, particularly in the context of climate change projections indicating stronger seasonality and more severe drought events.

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