Anthropogenic influences on the vegetation of Western Rajasthan

Summary Western Rajasthan, forming a part of the Thar desert, is admittedly dry, very hot in summer and is generally poor in vegetation. Though various causes for the origin of this desert have been attributed by climatologists, geographers and geologists, based on anthropological evidences it seems that there has been severe destruction of vegetation during the past. Over this landscape was superimposed the present day conditions, mainly the human influences, direct and indirect, on the vegetation, thus making the conditions still arid. From the observations it is seen that the water table in tube wells in some villages is good, patches of good density of vegetation are present where managed properly or dedicated to some deity. The rainfall, though scanty, is sufficient to support vegetation and if some rest is given the climax is reached especially where the nucleus exists. Though climatically the area is dry but not arid, soils are poor but not infertile and evidence is said to be there that in the past it supported good evergreen vegetation. Immediate establishment of vegetation, even on active sand dunes, can be seen even today if an area is protected rigidly from human and animal influences. During drought periods there may not be any augmentation of vegetation, yet those already established live, stabilise the soil and perpetuate the progress of vegetation. With protection not only the grasses and rank vegetation come up but even species like P. cineraria come up. It may therefore be safely said that Rajasthan desert, if not a man made desert is surely a man maintained desert.     

Anthropogenic transformation of the biomes, 1700 to 2000

Aim To map and characterize anthropogenic transformation of the terrestrial biosphere before and during the Industrial Revolution, from 1700 to 2000. Location Global. Methods Anthropogenic biomes (anthromes) were mapped for 1700, 1800, 1900 and 2000 using a rule‐based anthrome classification model applied to gridded global data for human population density and land use. Anthropogenic transformation of terrestrial biomes was then characterized by map comparisons at century intervals. Results In 1700, nearly half of the terrestrial biosphere was wild, without human settlements or substantial land use. Most of the remainder was in a seminatural state (45%) having only minor use for agriculture and settlements. By 2000, the opposite was true, with the majority of the biosphere in agricultural and settled anthromes, less than 20% seminatural and only a quarter left wild. Anthropogenic transformation of the biosphere during the Industrial Revolution resulted about equally from land‐use expansion into wildlands and intensification of land use within seminatural anthromes. Transformation pathways differed strongly between biomes and regions, with some remaining mostly wild but with the majority almost completely transformed into rangelands, croplands and villages. In the process of transforming almost 39% of earth's total ice‐free surface into agricultural land and settlements, an additional 37% of global land without such use has become embedded within agricultural and settled anthromes. Main conclusions Between 1700 and 2000, the terrestrial biosphere made the critical transition from mostly wild to mostly anthropogenic, passing the 50% mark early in the 20th century. At present, and ever more in the future, the form and process of terrestrial ecosystems in most biomes will be predominantly anthropogenic, the product of land use and other direct human interactions with ecosystems. Ecological research and conservation efforts in all but a few biomes would benefit from a primary focus on the novel remnant, recovering and managed ecosystems embedded within used lands.     

Dynamics of an Anthropogenic Fire Regime

Human interaction with fire and vegetation occurs at many levels of human population density and cultural development, from subsistence cultures to highly technological societies. The dynamics of these interactions with respect to wildland fire are often difficult to understand and identify at short temporal scales. Dendrochronological fire histories from the Missouri Ozarks, coupled with human population data, offer a quantitative means of examining historic (1680-1990) changes in the anthropogenic fire regime. A temporal analysis of fire scar dates over the last 3 centuries indicates that the percent of sites burned and fire intervals of anthropogenic fires are conditioned by the following four limiting factors: (a) anthropogenic ignition, (b) surface fuel production, (c) fuel fragmentation, and (d) cultural behavior. During an ignition-dependent stage (fewer than 0.64 humans/km²), the percent of sites burned is logarithmically related to human population (r² = 0.67). During a fuel-limited stage, where population density exceeds a threshold of 0.64 humans/km², the percent of sites burned is independent of population increases and is limited by fuel production. During a fuel-fragmentation stage, regional trade allows population densities to increase above 3.4 humans/km², and the percent of sites burned becomes inversely related to population (r² = 0.18) as decreases in fuel continuity limit the propagation of surface fires. During a culture-dependent stage, increases in the value of timber over forage greatly reduce the mean fire interval and the percent of sites burned. Examples of the dynamics of these four stages are presented from the Current River watershed of the Missouri Ozarks.     

The Multilevel Cycle of Anthropogenic Zinc

A comprehensive annual cycle for stocks and flows of zinc, based on data from circa 1994 and incorporating information on extraction, processing, fabrication, use, discard, recycling, and landfilling, was carried out at three discrete governmental unit levels—54 countries and 1 country group (which together comprise essentially all global anthropogenic zinc stocks and flows), nine world regions, and the planet as a whole. All of these cycles are available in an electronic supplement to this article, which thus provides a metadata set on zinc flows for the use of industrial ecology researchers. A "best estimate" global zinc cycle was constructed to resolve aggregation discrepancies. Among the most interesting results are the following: (1) The accumulation ratio, that is, addition to in-use stock as a function of zinc entering use, is positive and large (2/3 of zinc entering use is added to stock) (country, regional, and global levels); (2) secondary input ratios (fractions of input to fabrication that are from recycled zinc) and domestic recycling percentages (fractions of discarded zinc that are recycled) differ among regions by as much as a factor of six (regional level); (3) worldwide, about 40% of the zinc that was discarded in various forms was recovered and reused or recycled (global level); (4) zinc cycles can usefully be characterized by a set of ratios, including, notably, the utilization efficiency (the ratio of manufacturing waste to manufacturing output: 0.090) and the prompt scrap ratio (new scrap as a fraction of manufacturing input: 0.070) (global level). Because capturable discards are a significant fraction of primary zinc inputs, if a larger proportion of discards were recaptured, extraction requirements would decrease significantly (global level). The results provide a framework for complementary studies in resource stocks, industrial resource utilization, energy consumption, waste management, industrial economics, and environmental impacts.     

Anthropogenic drivers of gypsy moth spread

The gypsy moth, Lymantria dispar (L.), is a polyphagous defoliator introduced to Medford, Massachusetts in 1869. It has spread to over 860,000 km² in North America, but this still only represents ¼ of its susceptible host range in the United States. To delay defoliation in the remaining susceptible host range, the government maintains a barrier zone and a quarantine, reflecting a presumption that anthropogenic factors are important in the spread of gypsy moth. We develop a model framework that relates these factors along with biophysical characteristics to a county’s susceptibility to gypsy moth invasion. We then compile a dataset for counties within 200 km of the infested area and use trap catch data from 1999 to 2007 to estimate the probability of gypsy moth presence. As expected, gypsy moth is more likely to be found close to the population front and to traps that recorded moths in the previous year. However, when controlling for these factors, our most robust finding is that the use of wood for home heating and energy is consistently positively correlated with the presence of gypsy moth. In contrast, the movement of wood products by industry, which is actively regulated by state and federal governments, is rarely correlated with the presence of gypsy moth. This is consistent with effective regulation of the movement of goods by industry, but not by the public. Our findings provide empirical support for the importance and challenge of firewood as a vector for non-native forest insects.     

Anthropogenic disturbance and the risk of flea-borne disease transmission

Anthropogenic disturbance may lead to the spread of vector-borne diseases through effects on pathogens, vectors, and hosts. Identifying the type and extent of vector response to habitat change will enable better and more accurate management strategies for anthropogenic disease spread. We compiled and analyzed data from published empirical studies to test for patterns among flea and small mammal diversity, abundance, several measures of flea infestation, and host specificity in 70 small mammal communities of five biomes and three levels of human disturbance: remote/wild areas, agricultural areas, and urban areas. Ten of 12 mammal and flea characteristics showed a significant effect of disturbance category (six), biome (four), or both (two). Six variables had a significant interaction effect. For mammal-flea communities in forest habitats (39 of the 70 communities), disturbance affected all 12 characteristics. Overall, flea and mammal richness were higher in remote versus urban sites. Most measures of flea infestation, including percent of infested mammals and fleas/mammal and fleas/mammal species increased with increasing disturbance or peaked at intermediate levels of disturbance. In addition, host use increased, and the number of specialist fleas decreased, as human disturbance increased. Of the three most common biomes (forest, grassland/savanna, desert), deserts were most sensitive to disturbance. Finally, sites of intermediate disturbance were most diverse and exhibited characteristics associated with increased disease spread. Anthropogenic disturbance was associated with conditions conducive to increased transmission of flea-borne diseases.     

Exploratory Data Analysis of the Multilevel Anthropogenic Zinc Cycle

A comprehensive multilevel contemporary cycle for stocks and flows of zinc is analyzed by the tools of exploratory data analysis. The analysis is performed at three discrete organizational levels—country (53 countries and 1 country group that together comprise essentially all anthropogenic stocks and flows of zinc), world region (9 world regions), and the planet as a whole. The results demonstrate the following: (1) Exploratory data analysis provides valuable and otherwise unobtainable information about material flows, especially those across multiple spatial levels. (2) All distributions of countrylevel zinc stock and flow data are highly skewed, a few countries having large magnitudes, many having small magnitudes. Rates of fabrication of zinc-containing products for the countries are poorly correlated with rates of extraction, reflecting the fact that many countries that extract zinc do not fabricate products from zinc to any significant degree, and vice versa. (4) Virtually all countries are adding zinc to stock in the use phase (in galvanizing applications, zinc castings, etc.). These rates of addition are highly correlated with rates of zinc entering use in all regions, and are higher in regions under vigorous development. (5) With weak confidence, the rate of zinc landfilling by countries appears to be highly correlated with the rate of discard. (6) The statistical distributions of regional-level zinc cycle parameters are approximately log normal. (7) The extremes of normalized statistical distributions of zinc flow values are broader at lower spatial levels (country versus region, for example), but regional interquartile ranges for zinc entering use and zinc discards are higher at regional level then at country level.     

Anthropogenic noise changes arthropod abundances

Anthropogenic noise is a widespread and growing form of sensory pollution associated with the expansion of human infrastructure. One specific source of constant and intense noise is that produced by compressors used for the extraction and transportation of natural gas. Terrestrial arthropods play a central role in many ecosystems, and given that numerous species rely upon airborne sounds and substrate‐borne vibrations in their life histories, we predicted that increased background sound levels or the presence of compressor noise would influence their distributions. In the second largest natural gas field in the United States (San Juan Basin, New Mexico, USA), we assessed differences in the abundances of terrestrial arthropod families and community structure as a function of compressor noise and background sound level. Using pitfall traps, we simultaneously sampled five sites adjacent to well pads that possessed operating compressors, and five alternate, quieter well pad sites that lacked compressors, but were otherwise similar. We found a negative association between sites with compressor noise or higher levels of background sound and the abundance of five arthropod families and one genus, a positive relationship between loud sites and the abundance of one family, and no relationship between noise level or compressor presence and abundance for six families and two genera. Despite these changes, we found no evidence of community turnover as a function of background sound level or site type (compressor and noncompressor). Our results indicate that anthropogenic noise differentially affects the abundances of some arthropod families. These preliminary findings point to a need to determine the direct and indirect mechanisms driving these observed responses. Given the diverse and important ecological functions provided by arthropods, changes in abundances could have ecological implications. Therefore, we recommend the consideration of arthropods in the environmental assessment of noise‐producing infrastructure.     

Differentiating Natural and Anthropogenic Sources of Metals to the Environment

Since natural and anthropogenic sources can contribute to elevated levels of metals at remote and background sites, identifying the source of a metal is an important step in environmental risk assessment. Various source apportionment procedures are available to identify metal sources, and have been used extensively to determine sources in urban settings and to a lesser extent at remote sites. However, measuring metals at remote or background sites presents unique challenges with respect to experimental design. The state of the science in monitoring techniques and source apportionment procedures is discussed in terms of limitations and applicability to remote sites, and recommendations are made on maximizing information recovery through source apportionment procedures by incorporating appropriate experimental design.     

Anthropogenic disturbance changes the structure of arboreal tropical ant communities

We investigated the influence of anthropogenic disturbance on the structure of arboreal Formicidae communities in SE Asian lowland forests. Included were a primary forest and three disturbed forests which had been cut for crop planting and abandoned 5. 15, and 40 yr after agricultural use for natural regeneration. Ant communities of at least 10 individuals of one tree species were sampled from each forest type by fogging. Diversity and community structure differed clearly among forest types. During the course of forest regeneration ant communities became more and more similar to those of the primary forest. A surrogate analysis shows that ant communities of the primary forest cannot be distinguished from randomly composed communities. This is in contrast to the theoretical expectations according to which ant communities should be structured by interspecific competition that lead to a large degree of predictability. However, a deterministic pattern of ant communities is found in the disturbed forest. This indicates that human disturbance not only changes the faunistic composition of ant communities but could also change the dynamics of the whole system. The transition from stochastic to deterministic communities might be of general importance for understanding the mechanisms structuring communities in disturbed habitats.     

Anthropogenic stressors and riverine fish extinctions

Human activities are often implicated in the contemporary extinction of contemporary species. Concerning riverine fishes, the major biotic and abiotic threats widely cited include introduction of non-native species, habitat fragmentation and homogenization in stream flow dynamics due to the damming of rivers, dumping of organic loadings, degradation of the riverine habitat by agricultural practices and water abstraction for human and agricultural consumption. However, few studies have evaluated the role of each of these threats on fish extinction at large spatial scales. Focusing on Western Europe and the USA, two of the most heavily impacted regions on Earth, we quantify fish species loss per river basin and evaluate for the first time to what extent, if any, these threats have been promoting fish extinctions. We show that mean fish extinction rates during the last 110 years in both continents is ∼112 times higher than calculated natural extinction rates. However, we identified only weak effects of our selected anthropogenic stressors on fish extinctions. Only river fragmentation by dams and percentage of non-native species seem to be significant, although weak, drivers of fish species extinction. In our opinion, the most probable explanation for the weak effects found here comes from limitations of both biological and threats datasets currently available. Obtaining realistic estimates on both extinctions and anthropogenic threats in individual river basins is thus urgently needed.     

Anthropogenic noise pollution and wildlife diseases

There is a global rise in anthropogenic noise and a growing awareness of its negative effects on wildlife, but to date the consequences for wildlife diseases have received little attention. In this paper, we discuss how anthropogenic noise can affect the occurrence and severity of infectious wildlife diseases. We argue that there is potential for noise impacts at three main stages of pathogen transmission and disease development: (i) the probability of preinfection exposure, (ii) infection upon exposure, and (iii) severity of postinfection consequences. We identify potential repercussions of noise pollution effects for wildlife populations and call for intensifying research efforts. We provide an overview of knowledge gaps and outline avenues for future studies into noise impacts on wildlife diseases.     

人为噪声对动物的非听觉影响

噪声在环境中广泛存在,城市化的迅速发展也使野生动物接触到人为噪声的机会增大。越来越多的证据表明,人为噪声在许多方面影响着人类的健康以及野生动物的生存。对这些研究进行总结发现,噪声会改变动物的生理状态,使其处在较高的应激水平,进而影响动物的抗氧化能力和免疫能力,甚至使雏鸟的端粒缩短。人为噪声的存在还会影响动物的学习和认知能力,干扰动物觅食、交流等行为。这些因素累积就可能会降低动物后代的存活率,改变物种丰度,对动物的生存造成威胁。对人为噪声带来的非听觉影响的研究,有助于更全面地了解噪声的潜在危害,采取更为积极的缓解应对措施。     

Net Anthropogenic Phosphorus Accumulation in the Beijing Metropolitan Region

Phosphorus (P) is one of main pollution elements of eutrophication. P emissions from different pathways and sources are a key issue in the protection of water quality and sustainable watershed management practices. We have estimated net anthropogenic P accumulation (NAPA), as an index of P pollution potential in the Beijing metropolitan region, China. The NAPA estimation is based on an inventory of P fertilizer use, consumption of human food and animal feed, non-food P, and riverine P net flux. The overall average NAPA for 1991, 1997, 2003, and 2007 are 777, 943, 1218, and 1084 kg P km⁻² y⁻¹, about two times that reported in developed countries. The Urban unit has the largest NAPA (5526 kg P km⁻² y⁻¹), whereas Mentougou P was negative, outputting 34 kg P km⁻² y⁻¹. P input of fertilizer is the largest source of NAPA, accounting for 40.7% (455 kg P km⁻² y⁻¹) of the total P input, followed by non-food P and P in human food and animal feed. NAPA is closely related to land use, on average 5433 kg P km⁻² y⁻¹ in densely populated developed land, 503 kg P km⁻² y⁻¹ in agricultural land and 84 kg P km⁻² y⁻¹ in forest land. Human population density is the best single predictor of NAPA. Our results provide a basis for understanding the potential impact of anthropogenic P inputs on environmental problems, such as nation-wide water quality degradation under the current rapid urban expansion in modern China.