Wild, A. Soils, land and food: managing the land during the twenty-first century.

Food from agriculture supports around 6 billion people who inhabitthis planet today. The population is expected to increase toabout 7·2 and 8·3 billion by 2015 and 2030, respectively.This scenario requires increased food production. Food productioncan be raised by cultivating more land, increasing the yieldof each crop, growing two or three crops per year on the samepiece of land, or by a combination of these possibilities. Eachcan have problems. The best land, that is the land that is mostproductive,     

Rapid,habitat-related evolution of land snail colour morphs on reclaimed land

I made use of the known dates of reclamation (and of afforestations) in the IJsselmeerpolders in The Netherlands to assess evolutionary adaptation in Cepaea nemoralis. At 12 localities (three in each polder), I sampled a total of 4390 adult individuals in paired open and shaded habitats, on average 233 m apart, and scored these for genetic shell colour polymorphisms. The results show (highly) significant differentiation at most localities, although the genes involved differed per locality. Overall, though, populations in shaded habitats had evolved towards darker shells than those in adjacent open habitats, whereas a ‘Cain & Sheppard'' diagram (proportion yellow shells plotted against ‘effectively unbanded'' shells) failed to reveal a clear pattern. This might suggest that thermal selection is more important than visual selection in generating this pattern. Trait differentiation, regardless of whether they were plotted against polder age or habitat age, showed a linear increase of differentiation with time, corresponding to a mean rate of trait evolution of 15–31 kilodarwin. In conclusion, C. nemoralis is capable of rapid and considerable evolutionary differentiation over 1–25 snail generations, though equilibrium may be reached only at longer time scales.     

洪湖湖区土地利用／土地覆盖时空格局研究

利用1987,1993和1998年的遥感影像资料,研究了江汉平原洪湖湖区土地利用／土地覆盖的时空变化,土地覆盖类型分为水体,湖滩植被,洪泛地,农田,裸地和居民地6类,运用GIS（Arc/Info)软件,将不同时期的土地利用／土地覆盖的格局进行了清晰的空间表达;通过叠加3个不同时段的影像分类图,计算出各种土地利用／土地覆盖类型转变成其他类型的比例,在1987－1993年期间,水体和洪泛地的面积分别增加了15．54％和9．62％,而1993－1998年期间这两种类型的变化较小,分别为0．58％和3．19％,农田面积从1987年的577．62km^2减少到1998年的188．58km^2,减少约2／3,在研究期间,裸地面积没有明显变化,湖潍植被的面积在1987－1993年期间降低18．60%,而在1993－1998年期间增加8．47％,土地利用／土地覆盖状况的变化与湖区退田还湖及降雨状况的年际变化有关。     

Carbon emissions in the field of land use,land use change,and forestry in the Vietnam mainland

The biennial report of Vietnam includes updated information on the greenhouse gas emissions for the base years which are specified by the United Nations Framework Convention on Climate Change for reporting on greenhouse gas emissions by member nations of the Intergovernmental Panel on Climate Change. The estimation of greenhouse gas emissions in general and carbon emissions in particular in the field of land use, land use change, and forestry using advanced technology to provide the input data was recommended. Remote sensing technology with transparency, multi-time characteristics, and wide coverage is useful in this area. An experiment on carbon emission estimation was carried out based on land cover change over ten years between 2002 and 2012. The results obtained by remote sensing data classification for the land cover categories achieved a reliability of 68% for the year 2002 and 67% for the year 2012. Data in relation to the land cover change, soil zoning, and ecological/climate zoning in the Vietnamese mainland, through the process of integrating, processing, and synthesizing data, and using the reported activity data and carbon emission coefficients, were input into the Agriculture and Land Use Greenhouse Gas Inventory Software for carbon emission estimations based on the quality control and quality assurance work.

     

The numbers of land birds, waders, sea birds, land Crustacea, and certain insects on the lagoon islands of Aldabra Atoll

A study was made of the determinants of numbers of species of land birds, waders, breeding sea birds, land Crustacea, and insects on 77 of the lagoon islands of Aldabra Atoll in the Western Indian Ocean. By comparison with other studies, number of plant species and the structural complexity of the vegetation are not significantly related to the number of land bird species; log area accounts for 66.5% of the variance in number. Log area is also the most important factor influencing the number oI wader species. The variables considered account for only 36.2% of the variance in breeding sea bird species; this low figure suggests that other factors are of importance. Isolation of an island is the most important of those considered. Nearly half the variance in the number of insects groups is determined by log number of plant species, while the complexity of the vegetation structure is the only significant variable predicting the number of species of land Crustacea. Differences between the findings of this and other studies are attributed to the particular characteristics or the islands and species considered.
Relatively low z values are found (0.205 for land birds, 0.174 for waders, and 0.136 for land Crustacea), suggesting that inter-island distances do not represent great barriers to the species concerned and immigration and extinction rates are probably in equilibrium.     

Urbanization,land tenure security and vector-borne Chagas disease

Modern cities represent one of the fastest growing ecosystems on the planet. Urbanization occurs in stages; each stage characterized by a distinct habitat that may be more or less susceptible to the establishment of disease vector populations and the transmission of vector-borne pathogens. We performed longitudinal entomological and epidemiological surveys in households along a 1900 × 125 m transect of Arequipa, Peru, a major city of nearly one million inhabitants, in which the transmission of Trypanosoma cruzi, the aetiological agent of Chagas disease, by the insect vector Triatoma infestans, is an ongoing problem. The transect spans a cline of urban development from established communities to land invasions. We find that the vector is tracking the development of the city, and the parasite, in turn, is tracking the dispersal of the vector. New urbanizations are free of vector infestation for decades. T. cruzi transmission is very recent and concentrated in more established communities. The increase in land tenure security during the course of urbanization, if not accompanied by reasonable and enforceable zoning codes, initiates an influx of construction materials, people and animals that creates fertile conditions for epidemics of some vector-borne diseases.     

Analysis of land consolidation projects and their impact on land use change,landscape structure,and agricultural land resource protection: case studies of Pilsen-South and Pilsen-North (Czech Republic)

Within the countries of the former socialist bloc, the changes in the politico-economic system at the end of the 1990s created a situation where it was (and still is) necessary to restore agricultural land resource property rights, to adjust the structure of agricultural land to current needs and to improve the current state of environmental resources. This case study covers 19 cadastral areas in the western part of the Czech Republic that were affected by the land consolidation process during 2000–2006. The main task of this study was to document how land consolidation processes could affect the change of land use and landscape structure and whether the land consolidation planners take into account the protection of natural resources. The increased acreage of grasslands was the most important change which has occurred in the land use in the 19 analysed cadastral areas, before and after land consolidations. In the studied area, the changes of land use involved 6.8 % of the total land consolidation area. This area of grassland significantly increased the protection of agricultural land from water erosion. In terms of changes in the landscape structure, the construction of new field road networks is the most important result. The results confirm the importance of land consolidation processes not only for the organization and recovery of ownership and cadastral records but also for the improvement of agricultural use of landscape and protection of natural resources such as soil, water and plant and animal communities.     

Patterns of land use,extensification, and intensification of Brazilian agriculture

Sustainable intensification of agriculture is one of the main strategies to provide global food security. However, its implementation raises enormous political, technological, and social challenges. Meeting these challenges will require, among other things, accurate information on the spatial and temporal patterns of agricultural land use and yield. Here, we investigate historical patterns of agricultural land use (1940–2012) and productivity (1990–2012) in Brazil using a new high‐resolution (approximately 1 km²) spatially explicit reconstruction. Although Brazilian agriculture has been historically known for its extensification over natural vegetation (Amazon and Cerrado), data from recent years indicate that extensification has slowed down and was replaced by a strong trend of intensification. Our results provide the first comprehensive historical overview of agricultural land use and productivity in Brazil, providing clear insights to guide future territorial planning, sustainable agriculture, policy, and decision‐making.     

Molecular phylogeny of land and freshwater planarians (Tricladida, Platyhelminthes): from freshwater to land and back

The suborder Tricladida (phylum Platyhelminthes) comprises the well-known free-living flatworms, taxonomically grouped into three infraorders according to their ecology: Maricola (marine planarians), Paludicola (freshwater planarians), and Terricola (land planarians). Molecular analyses have demonstrated that the Paludicola are paraphyletic, the Terricola being the sister group of one of the three paludicolan families, the Dugesiidae. However, neither 18S rDNA nor COI based trees have been able to resolve the relationships among species of Terricola and Dugesiidae, particularly the monophyly of Terricola. Here, we present new molecular data including sequences of nuclear genes (18S rDNA, 28S rDNA) and a mitochondrial gene (COI) of a wider sample of dugesiid and terricolan species. The new sequences have been analyzed, together with those previously obtained, in independent and concatenated analyses using maximum likelihood and bayesian methods. The results show that, although some parts of the trees remain poorly resolved, they support a monophyletic origin for Terricola followed by a likely return of some species to freshwater habitats. Relationships within the monophyletic group of Dugesiidae are clearly resolved, and relationships among some terricolan subfamilies are also clearly established and point to the need for a thorough revision of Terricola taxonomy.     

Human land use, agriculture, pesticides and losses of imperiled species

Aim  Anthropogenic habitat loss is usually cited as the most important cause of recent species' extinctions. We ask whether species losses are in fact more closely related to habitat loss than to any other aspect of human activity such as use of agricultural pesticides, or human population density (which reflects urbanization).
Location  Canada.
Methods  We statistically compared areas in Canada where imperiled species currently occur, versus areas where they have been lost. Using multiple regressions, we relate the numbers of species that had suffered range reductions in an ecoregion to variables that represent present habitat loss, pesticide use and human population density.
Results  We find high losses of imperiled species in regions with high proportions of agricultural land cover. However, losses of imperiled species are significantly more strongly related to the proportion of the region treated with agricultural pesticides. The relationship between species losses and area treated with pesticides remains significant after controlling for area in agriculture.
Main conclusions  Our results are consistent with the hypothesis that agricultural pesticide use, or something strongly collinear with it (perhaps intensive agriculture more generally), has contributed significantly to the decline of imperiled species in Canada. Habitat conversion per se may be a less important cause of species declines than how that converted habitat is used.     

Species richness in Madeiran land snails, and its causes

Aim  To unravel the reasons why a group of islands of 800 km² area should support over 200 extant land snail species.
Location  The temperate Atlantic Madeiran archipelago.
Methods  Distributional surveys and model testing.
Results  Repeated volcanic events have changed the topography of the islands and created periodic further isolates. There has been climatic fluctuation and varying sea level. Individual locations are not species-rich, but there is replacement from one subregion to another. Evidence of competitive interactions is lacking.
Main conclusions  High diversity results from the fortuitous coincidence of rates of geological and climatic change and isolation on the one hand, and migration and genetic divergence on the other. Hubbell's neutral model of biodiversity explains species richness if a factor is added describing structural instability or periodicity, here called the geodetic rate. This geodetic, biological interaction can explain why some archipelagos are species-rich.     

Foerstia and recent interpretations of early, vascular land plants

Schopf, James M. 1978 04 15: Foerstia and recent interpretations of early, vascular land plants
Foerstia should be regarded as a marine fucoid, contrary to the recent interpretation of Gray and Boucot who relate these fossils to land plants. Although the megaspore coats are resistant and may be waxy, the thallus lacks cuticle and it has internal filamentous tissue like Fucus and other fucoidal algae. The megaspores, borne in fucoidal conceptacles, are unusual and may be forerunners of the more reduced oocytes that occur in modern Fucales. Detailed illustrations are provided. There is no evidence that these plants have ever been anything but marine. Likewise, tubular microfossils that show internal thickenings and occur in Ordovician and Silurian marine deposits should not be designated 'tracheid-like', as done by Gray and Boucot, because it is unlikely they represent land plants or function in conduction. They show a surprisingly consistent association with Chitinozoa. They illustrate the adage that structures identified simply by their form may be of diverse origin. Neither Foersria nor the annulate tubules are relevant to the origin of temestrial vegetation.     

粤北低山林地改建梯田对土壤碳、氮、磷及其化学计量特征的影响

为了阐明土地利用方式转变对土壤碳、氮、磷及其化学计量特征的影响,以粤北低山区4种土地利用方式:自然林地、坡地果园、旱作梯田和稻作梯田为研究对象,探索20年生林地向梯田转变后土壤有机碳(OC)、全氮(TN)和全磷(TP)的含量、储量及化学计量变化特征。结果表明: 土地利用转变明显改变了土壤碳、氮、磷含量和化学计量特征,随着土壤深度增加,旱作梯田和稻作梯田OC、TN含量呈显著下降趋势,自然林地和坡地果园呈“V”字型变化趋势,4种土地利用方式TP变化趋势不明显。土壤剖面OC含量以稻作梯田最高,均值为12.36 g·kg^-1,其次为林地(10.32 g·kg^-1)和旱作梯田(8.80 g·kg^-1),坡地果园最低(5.96 g·kg^-1);TN含量表现为稻作梯田(1.01 g·kg^-1)>旱作梯田(0.78 g·kg^-1)>林地(0.66 g·kg^-1)>坡地果园(0.33 g·kg^-1);TP含量以旱作梯田(0.71 g·kg^-1)最高,坡地果园(0.22 g·kg^-1)最低。4种土地利用方式土壤C∶N为8.87～22.94,以坡地果园土壤最高;C∶P为8.73～81.74,N∶P为0.77～5.13,均以林地土壤最高。土地利用方式、土壤深度及两者交互作用显著影响土壤碳、氮、磷及其化学计量特征,而土壤容重、pH值和黏粒含量也是重要的影响因素。研究结果可为粤北低山林地的土地利用和梯田生态系统的合理施肥提供科学依据。     

Urban land rights and child nutritional status in Peru, 2004

Advocates of land-titling programs in developing countries posit that these programs lead to a multitude of benefits, including health improvements. This paper presents the results of a child health survey of several Lima communities after various time exposures to Peru's urban land-titling program. The results provide suggestive evidence that improved property rights increase children's weight but not their height, which is consistent with previous work on the topic. However, titles also appear to raise children's risk of being overweight or obese, implying that the observed weight gain is not necessarily an improvement in nutritional status.     

Tibetan land use and change near khawa karpo, Eastern Himalayas

Collaborating Authors: Bee Gunn, Wayne Law, George Yatskievych, Wu Sugong, Fang Zhendong, Ma Jian, Wang Yuhua, Andrew Willson, Peng Shengjing, Zhang Chuanling, Sun Hongyan, Meng Zhengui, Liu Lin, Senam Dorji, Ana, Liqing Wangcuo, Sila Cili, Adu, Naji, Amu, Sila Cimu, Sila Lamu, Lurong Pingding, Zhima Yongzong, Loangbao, Bianma Cimu, Gerong Cili, Wang Kai, Sila Pingchu, Axima, and Benjamin Staver.TIBETAN LAND USE AND CHANGE NEAR KHAWA KARPO, EASTERN HIMALAYAS. Economic Botany 59(4):312-325, 2005. Tibetan land use near Khawa Karpo, Northwest Yunnan, China, incorporates indigenous forest management, gathering, pastoralism, and agriculture. With field-based GIS, repeat photography, and Participatory Rural Appraisal we quantitatively compare land use between higher and lower villages, and between villages with and without roads. Households in higher elevation (> 3,000 meters) villages cultivate more farmland (z = -5.387, P ≤ 0.001), a greater diversity of major crops (z = -5.760, P < 0.001), a higher percentage of traditional crops, and fewer cash crops (z = -2.430, P = 0.015) than those in lower elevation villages (< 2,500 meters). Villages with roads grow significantly more cash crops (z = -6.794, P ≤ 0.001). Both lower villages and villages with roads travel farther to access common property resources. Historical analyses indicate agricultural intensification in valleys, an increase in houses, new crop introduction, hillside aforestation, cessation of hunting, glacial retreat, and timberline advance within the past century. We suggest that Tibetan land use reveals trade-offs between high, remote villages and lower villages near roads. Higher villages offer abundant land and access to natural resources but short growing seasons and little market access; in contrast, lower villages have road and market access, an extended growing season, and modern technology, but limited access to land and many other natural resources.