Exclusion of agricultural lands in spatial conservation prioritization strategies: consequences for biodiversity and ecosystem service representation

Agroecosystems have traditionally been considered incompatible with biological conservation goals, and often been excluded from spatial conservation prioritization strategies. The consequences for the representativeness of identified priority areas have been little explored. Here, we evaluate these for biodiversity and carbon storage representation when agricultural land areas are excluded from a spatial prioritization strategy for South America. Comparing different prioritization approaches, we also assess how the spatial overlap of priority areas changes. The exclusion of agricultural lands was detrimental to biodiversity representation, indicating that priority areas for agricultural production overlap with areas of relatively high occurrence of species. By contrast, exclusion of agricultural lands benefits representation of carbon storage within priority areas, as lands of high value for agriculture and carbon storage overlap little. When agricultural lands were included and equally weighted with biodiversity and carbon storage, a balanced representation resulted. Our findings suggest that with appropriate management, South American agroecosystems can significantly contribute to biodiversity conservation.     

Uncertainty in estimating land use and management impacts on soil organic carbon storage for US agricultural lands between 1982 and 1997

Uncertainty was quantified for an inventory estimating change in soil organic carbon (SOC) storage resulting from modifications in land use and management across US agricultural lands between 1982 and 1997. This inventory was conducted using a modified version of a carbon (C) accounting method developed by the Intergovernmental Panel on Climate Change (IPCC). Probability density functions (PDFs) were derived for each input to the IPCC model, including reference SOC stocks, land use/management activity data, and management factors. Change in C storage was estimated using a Monte‐Carlo approach with 50 000 iterations, by randomly selecting values from the PDFs after accounting for dependencies in the model inputs. Over the inventory period, mineral soils had a net gain of 10.8 Tg C yr^?1, with a 95% confidence interval ranging from 6.5 to 15.3 Tg C yr^?1. Most of this gain was due to setting‐aside lands in the Conservation Reserve Program. In contrast, managed organic soils lost 9.4 Tg C yr^?1, with a 95% confidence interval ranging from 6.4 to 13.3 Tg C yr^?1. Combining these gains and losses in SOC, US agricultural soils accrued 1.3 Tg C yr^?1 due to land use and management change, with a 95% confidence interval ranging from a loss of 4.4 Tg C yr^?1 to a gain of 6.9 Tg C yr^?1. Most of the uncertainty was attributed to management factors for tillage, land use change between cultivated and uncultivated conditions, and C loss rates from managed organic soils. Based on the uncertainty, we are not able to conclude with 95% confidence that change in US agricultural land use and management between 1982 and 1997 created a net C sink for atmospheric CO₂.     

Land use change and carbon cycle in arid and semi-arid lands of East and Central Asia

Dramatic changes in land use have occurred in arid and semi-arid landsof Asia during the 20th century. Grassland conversion into croplands and ecosystem degradation is widespread due to the high growth rate of human population and political reforms of pastoral systems. Rangeland degradation made many parts of this region vulnerable to environmental and political changes. The collapse of the livestock sector in some states of central Asia, expansion of livestock inChina and intensive degradation of grasslands in China are examples of the responses of pastoral systems to these changes over the past decades. Carbon dynamics in this region is highly variable in space and time. Land use/cover changes with widespread reduction of forest and grasslands increased carbon emission from the region.     

Comparison of the distribution patterns of BK polyomavirus lineages among China, Korea and Japan: Implications for human migrations in northeast Asia

BKV is widespread among humans, infecting children asymptomatically and then persisting in renal tissue. Based on the serological or phylogenetic method, BKV isolates worldwide are classified into four subtypes (I–IV), with subtypes I and IV further divided into several genetically-distinct subgroups. Since, similarly to JCV, a close relationship exists between BKV lineages and human populations, BKV should be useful as a marker to trace human migrations. To elucidate ancient human migrations in northeast Asia, urine samples were collected from immunocompetent elderly patients in Shanghai, China; Anyang, South Korea; and various locations in Japan. Partial and complete BKV genomes from these samples were amplified and sequenced using PCR, and the determined sequences were classified into subtypes and subgroups by phylogenetic and SNP analyses. In addition, based on an SNP analysis, the major subtype I subgroup (I/c) was classified into two subdivisions, I/c/Ch and I/c/KJ. The distribution patterns of BKV subgroups and subdivisions among the three regions were compared. Some aspects of the subgroup and subdivision distribution were more similar between Korea and Japan, but others were more similar between China and Korea or between China and Japan. Based on these findings, we inferred various northeast Asian migrations. Most of the JCV-based inferences of northeastern Asian migrations were consistent with those based on BKV, but the previously suggested migration route from the Asian continent to the Japanese archipelago seemed to need revision.     

Effects of agricultural land use on water chemistry of mire pools in the Ishikari Peatland, northern Japan

Concomitant with farmland development in the Ishikari Peatland of northern Japan, deterioration of water chemistry has become increasingly evident at mire pools there. Using spatial analysis methods with a geographic information system and a statistical methodology, this study examined the effects of agricultural land use on the pool water chemistry. A water chemistry survey of several pools showed that nitrogen, phosphorus, and suspended-solid concentrations were remarkably higher than those in pools that had been undisturbed or less-disturbed by land-use development. Principal component analysis (PCA) was conducted to summarize water chemistry variables. Correlation analysis was conducted between the principal component (PC) scores and land-use variables to clarify land-use effects. Results of the PCA showed that the water chemistry variances were accounted for by the first two PCs: PC1 included farmland subsurface drainage containing nitrogen, specifically nitrate, and mineral ions; PC2 included farmland surface drainage containing soil particles and ammonium nitrogen. These PC scores were also affected by the number of inflow ditches and the total area of farmland located within the drainage catchment of inflow ditches leading to the pools. Results suggest that farmland subsurface and surface drainage water flowing into the pools degraded the water chemistry. The extent of the effects of drainage water depended on agricultural practices such as fertilizer application and paddy-field puddling (i.e., mechanical homogenization of water-saturated soil). Accordingly, water chemistry of the study pools was affected by agricultural practices and by the amount of farmland in the drainage basin, engendering eutrophication, and the deterioration of water chemistry. Therefore, preservation of water chemistry necessitates changes in agricultural practices, such as improving fertilizer application methods, along with measures related to land-use planning such as changing the drainage ditches’ flow direction.     

Troop size,home range area and seasonal range use of the Japanese macaque in the Northern Japan Alps

Home range area and habitat use of the wild Japanese macaque (Macaca fuscata) were investigated between elevations of 600m and 3000m in the Northern Japan Alps, in areas where there is great variation in vegetation type. A total of 22 troops were located either visually or by radiotracking from December 1996 to February 2000. The average troop size was 48.4 individuals, the average ranging area (65% probability distribution calculated using the adaptive kernel method) was 3.7km² and the average elevation of each troop varied from 740m to 1458m. Two troop types were distinguished according to their habitat use: (i) rural type groups frequently utilized cultivated land (n=12); and (ii) natural type groups never utilized cultivated land (n=10). Natural groups inhabited higher elevation areas and showed a greater dependency on deciduous broad-leaved forests during all seasons. In contrast, rural groups utilized the larch plantation more in spring, and the red pine forest in summer. Rural groups were observed on cultivated lands more often from summer to winter than in spring. The size of the rural groups was twice as large as that of the natural groups. Troop size and home range area showed significant correlation within each group type. The per capita home range area of rural groups was smaller than that of natural groups. These results suggest that per capita home range area is negatively correlated with habitat quality.     

Extensive land use and the logic of the latifundio: A case study in Guanacaste Province,Costa Rica

Traditional explanations of extensive land use on large unproductive estates in Latin American have failed to understand important aspects of the economic and political logic behind such enterprises. This article examines the reasons for the low productivity of cattle ranches over a period which spans the consolidation of haciendas in a frontier zone and their subsequent integration into the international beef market. The persistence of extensive land use in a modern export economy is explained as resulting from characteristics of the world beef market, local ecology, the Costa Rican credit and tax systems, and the social composition and political power of the landowning class.     

Habitat use by endemic and introduced rodents along a gradient of forest disturbance in Madagascar

We used logistic and Poisson regression models to determine factors of forest and landscape structure that influence the presence and abundance of rodent species in the rain forest of Ranomafana National Park in southeastern Madagascar. Rodents were collected using live-traps along a gradient of human disturbance. All five endemic rodent species (Nesomys rufus, N. audeberti, Eliurus tanala, E. minor and E. webbi) and the introduced rat Rattus rattus were captured in both secondary and primary forests, but the introduced Mus musculus was only trapped in secondary forest. The abundance of R. rattus increased with the level of habitat disturbance, and it was most common in the heavily logged secondary forest. Furthermore, the probability of the presence of R. rattus increased with decreasing distance from forest edge and decreasing canopy cover, while the probability of presence increased with increasing herbaceous cover, altitude and overstory tree height. The species was never observed farther than 500 m away from human habitation or camp-site. N. rufus prefered selectively-logged forest at altitudes above 900 m a.s.l. Its probability of presence increased with increasing canopy cover, herbaceous cover and distance from forest edge, and with decreasing density of fallen logs, overstory tree height and distance from human habitation. N. audeberti prefered heavily-logged areas, while E. tanala was the only species occurring along the entire range of forest disturbance. We suggest that in the Ranomafana National Park the spread of R. rattus is associated with deforestation.     

Sparing land for nature: exploring the potential impact of changes in agricultural yield on the area needed for crop production

How can rapidly growing food demands be met with least adverse impact on nature? Two very different sorts of suggestions predominate in the literature: wildlife‐friendly farming, whereby on‐farm practices are made as benign to wildlife as possible (at the potential cost of decreasing yields); and land‐sparing, in which farm yields are increased and pressure to convert land for agriculture thereby reduced (at the potential cost of decreasing wildlife populations on farmland). This paper is about one important aspect of the land‐sparing idea – the sensitivity of future requirements for cropland to plausible variation in yield increases, relative to other variables. Focusing on the 23 most energetically important food crops, we use data from the Food and Agriculture Organisation (FAO) and the United Nations Population Division (UNPD) to project plausible values for 2050 for population size, diet, yield, and trade, and then look at their effect on the area needed to meet demand for the 23 crops, for the developing and developed worlds in turn. Our calculations suggest that across developing countries, the area under those crops will need to increase very considerably by 2050 (by 23% under intermediate projections), and that plausible variation in average yield has as much bearing on the extent of that expansion as does variation in population size or per capita consumption; future cropland area varies far less under foreseeable variation in the net import of food from the rest of the world. By contrast, cropland area in developed countries is likely to decrease slightly by 2050 (by 4% under intermediate projections for those 23 crops), and will be less sensitive to variation in population growth, diet, yield, or trade. Other contentious aspects of the land‐sparing idea require further scrutiny, but these results confirm its potential significance and suggest that conservationists should be as concerned about future agricultural yields as they are about population growth and rising per capita consumption.     

Genetic evidence of intercontinental movement of avian influenza in a migratory bird: the northern pintail (Anas acuta)

The role of migratory birds in the movement of the highly pathogenic (HP) avian influenza H5N1 remains a subject of debate. Testing hypotheses regarding intercontinental movement of low pathogenic avian influenza (LPAI) viruses will help evaluate the potential that wild birds could carry Asian-origin strains of HP avian influenza to North America during migration. Previous North American assessments of LPAI genetic variation have found few Asian reassortment events. Here, we present results from whole-genome analyses of LPAI isolates collected in Alaska from the northern pintail (Anas acuta), a species that migrates between North America and Asia. Phylogenetic analyses confirmed the genetic divergence between Asian and North American strains of LPAI, but also suggested inter-continental virus exchange and at a higher frequency than previously documented. In 38 isolates from Alaska, nearly half (44.7%) had at least one gene segment more closely related to Asian than to North American strains of LPAI. Additionally, sequences of several Asian LPAI isolates from GenBank clustered more closely with North American northern pintail isolates than with other Asian origin viruses. Our data support the role of wild birds in the intercontinental transfer of influenza viruses, and reveal a higher degree of transfer in Alaska than elsewhere in North America.     

A comparison of the diversity and structure of butterfly communities in semi-natural and human-modified grassland habitats at the foot of Mt. Fuji, central Japan

To examine the effects of human land use and disturbance on butterfly communities we compared the diversity and structure of communities in relatively undisturbed, semi-natural grassland habitats and highly disturbed, human-modified ones. Comparisons were based on transect counts conducted at 6 study sites at the foot of Mt. Fuji in the cool temperate zone of central Japan during 1995. Out of the six community parameters used in the analyses, the species richness, species diversities H and 1/, and dominance indices were significantly different between the two habitat types stated above. That is, butterfly communities in semi-natural habitats had higher species richness and diversity, and lower dominance indices than those in human-modified ones. This suggests that heavy land modification and disturbance to semi-natural habitats change greatly its butterfly community structure, which, indeed, leads to decreasing species richness and diversity mainly due to the loss of species that are confined to semi-natural habitats. Through the comparisons of various species' characteristics, it was found that the species confined to semi-natural habitats had lower population abundance, fewer generations per year, more restricted local distributions, and narrower geographic range size in Japan than the other component species. Based on our results, it is critical that the persistence of the species that are limited to semi-natural habitats be ensured in order to maintain high species richness and diversity in grassland butterfly communities. Thus, conservation plans that retain as much semi-natural habitat as possible within the process of human grassland use, development, and modification are needed.     

Habitat use of urban Tree Sparrows in the process of urbanization:Beijing as a case study

The Tree Sparrow (Passer montanus) is a dom-inant species in urban bird communities.With the devel-opment of urbanization,the habitats and sources of food for Tree Sparrows are decreasing.Can the urban Tree Sparrow adapt to changes in the urban environment? To answer this question,we studied the habitat use of Tree Sparrows in eight types of urban areas in Beijing.The results show that the number of both breeding and winter-ing Tree Sparrows decreased with increasing urbanization.The habitat use of Tree Sparrows,analyzed using stepwise discriminant analysis,was positively correlated with the number of brick bungalows,coniferous and broad-leaved trees and air conditioners.It was negatively correlated with the area of high buildings and hardened roads,pedestrian and automobile flux.This indicates that the Tree Sparrow had not adapted to rapid urbanization even though it is a generally adaptable species.Urban planning should take birds such as the Tree Sparrow into consideration.     

Soil organic carbon stock change due to land use activity along the agricultural frontier of the southwestern Amazon,Brazil, between 1970 and 2002

The southwestern portion of the Brazilian Amazon arguably represents the largest agricultural frontier in the world, and within this region the states of Rondônia and Mato Grosso have about 24% and 32% of their respective areas under agricultural management, which is almost half of the total area deforested in the Brazilian Amazon biome. Consequently, it is assumed that deforestation in this region has caused substantial loss of soil organic carbon (SOC). In this study, the changes in SOC stocks due to the land use change and management in the southwestern Amazon were estimated for two time periods from 1970–1985 and 1985–2002. An uncertainty analysis was also conducted using a Monte Carlo approach. The results showed that mineral soils converted to agricultural management lost a total of 5.37 and 3.74 Tg C yr^?1 between 1970–1985 and 1985–2002, respectively, along the Brazilian Agricultural Frontier in the states of Mato Grosso and Rondônia. Uncertainties in these estimates were ±37.3% and ±38.6% during the first and second time periods, respectively. The largest sources of uncertainty were associated with reference carbon (C) stocks, expert knowledge surveys about grassland condition, and the management factors for nominal and degraded grasslands. These results showed that land use change and management created a net loss of C from soils, however, the change in SOC stocks decreased substantially from the first to the second time period due to the increase in land under no‐tillage.     

喀斯特峰丛坡地不同土地利用方式下土壤N、P空间变异特征

基于网格点(5 mx5 m)采样法采集土壤样品,利用经典统计学和地统计学方法,研究了喀斯特峰丛坡地不同土地利用方式(火烧迹地、刈割地、草地、封育地)下表层(0～20cm)土壤氮、磷的空间变异特性.结果表明:研究区4种不同土地利用方式土壤全氮(TN)、全磷(TP)、速效氮(AN)、速效磷(AP)均为中等程度变异,含量分别为5.40 ～6.26 g·kg-1、1.24 ～1.44 g·kg-1、365.87～507.32 mg·kg-1、3.91 ～8.04 mg·kg-1,封育地、火烧迹地土壤质量优于草地和刈割地;4种土地利用方式中火烧AN、火烧AP、刈割AN、封育TN的半方差函数最佳拟合模型为球状模型,火烧TN、刈割TN、刈割AP最佳拟合模型为指数模型,其他指标的最佳拟合模型均为高斯模型.刈割TP、火烧TP、草地TP、刈割TN、火烧AP、草地AP、封育TP表现为强烈的空间自相关性,其他土壤养分表现为中等的空间自相关.4种土地利用类型土壤TN与AN、TP与AP具有相似的空间分布格局.火烧、刈割处理TN和AN呈凹形分布,TP和AP呈单峰分布特征,中下坡含量最高,往两端含量逐渐降低;草地TN、AN、TP、AP 4种养分含量均随着坡位的升高而降低;封育样地中4种养分呈类似凹形分布,中间含量低,两端略微升高.土地利用方式的变化改变了喀斯特峰丛坡地土壤养分质量,造成了土壤养分空间格局的变化,因此,在地形破碎、土层浅薄的喀斯特地区进行生态恢复与重建时,应采取合理土地利用方式,进行保护和适度开发,提高喀斯特退化生态系统土壤质量.     

Habitat utilization patterns of sympatric populations of Pseudomys gracilicaudatus and Rattus lutreolus in coastal heathland: A multivariate analysis

Abstract Habitat usage characteristics of two species of native murid rodents, Pseudomys gracilicaudatus and Rattus lutreolus were investigated on an area of coastal heathland at Myall Lakes National Park. A grid of 151 trap stations comprising 17 traplines was positioned across a mosaic of habitats. At each trap station 19 structural vegetation and physical variables known to affect the microdistribution of small mammals were measured. Multivariate statistical procedures identified those microhabitat variables that contribute to individual species' habitat use and habitat partitioning, and reduce potential competition for space. Cluster analysis classified trap stations into one of six habitat types that were mapped on the study area, identifying a heterogeneous assemblage of interlocking habitats. The pattern is a consequence of topographic variation on the site and, to a lesser extent, its fire history. Trapping results show P. gracilicaudatus and R. lutreolus exhibit similar macrohabitat selection, preferring topographically low habitats, with both species predominantly occupying short dense heath with dense sedge cover. The high overlap in macrohabitat use is greatly reduced when considered trap station by trap station, so that discriminant function and multiple regression analyses demonstrate marked microhabitat selection. Elevation was a highly significant variable, accounting for 41% and 27% of the variance in the habitat used by P. gracilicaudatus and R. lutreolus, respectively. This variable represents a soil moisture gradient that determines changes in the floristic and structural components of the biotic environment. Two other structural vegetation variables and vegetation height contributed 30% of the variance in P. gracilicaudatus distribution. Sedge cover was found to be significant and explained 13% of the variance in R. lutreolus distribution. Within-habitat separation was explained best with a linear combination of variables in a discriminant function, rather than by any single variable. Differential microhabitat selection, interference competition and diet separation appear to be the major factors facilitating coexistence of these two species.     

Habitat quality and connectivity in agricultural landscapes: The role of land use systems at various scales in time

Connectivity is a key concept of landscape ecology as it relates to flows and movements of organisms as driven by landscape structure. More and more aspects of landscape heterogeneity are considered in measuring connectivity, as the diversity of crops in agricultural landscapes. In this paper, we explored the value of considering changes and cumulated effects of connectivity over time. As an example, we analysed connectivity among patches influenced by maize over 7 years in an agricultural landscape in Brittany, France.Clear temporal patterns appeared: maize is concentrated in certain parts of the landscape, but over the period the whole area, 70% of the landscape, used for maize was connected. Instead of discrete patches, maize may produce large clusters allowing movement from patch to patch from year to year. This reinforces the importance of understanding land use allocation rules within farms and landscapes to evaluate the ecological effects of agriculture.     

Traveling or stopping of migrating birds in relation to wind: an illustration for the osprey

Although it is often assumed that birds strongly prefer tailwindsfor their migratory flights, we predict that a strategy of nowind selectivity (traveling independently of winds) may be morefavorable than wind selectivity (traveling on tailwind occasionsbut stopping to rest under headwind occasions) for birds withlow energy costs of travel relative to rest and for birds thatcannot use stopover time for efficient fuel deposition. We testthis prediction by analyzing the daily traveling or stoppingas recorded by satellite tracking of five ospreys Pandion haliaetus,a species often using energy-saving thermal soaring, duringtheir migration between northern Europe and Africa. Besideswind, precipitation is another weather factor included in theanalyses because thermal soaring migrants are expected to stopand rest in rainy weather. In logistic regression analyses,taking into account the effects of latitude, behavior on previousday, season, date, and individual for discriminating betweentraveling and stopping days, we found a lack of influence ofwinds, suggesting that the ospreys travel or stop without regardto wind. This lack of wind selectivity under light and moderatewinds is in agreement with our prediction. We expect a low degreeof wind selectivity and thus regular flights under headwindsalso among other types of birds that cannot use stopping timefor efficient foraging and fuel deposition. We also found anunexpected lack of influence of precipitation, possibly becauseof relatively few instances with rainfall in combination withpoor geographic precision for estimates of this weather variable.