Lake Titicaca Region Research Articles

Problems with combining modelling and social science approaches to understand artisanal fisheries bycatch

AbstractAimArtisanal fisheries account for 40% of the world's fisheries catch, yet its environmental impacts remain poorly understood. This is especially the case in developing countries. In this study, we sought to integrate Local Fisher's Knowledge with distribution modelling to estimate the annual bycatch of Titicaca Grebe (Rollandia microptera), an endangered endemic bird from Lake Titicaca whose main anthropogenic threat is bycatch.LocationLake Titicaca, Peru and Bolivia.MethodsWe conducted transect and point counts of fishing nets in March–September 2022 and conducted interviews with fishers across the Lake Titicaca region. Using bathymetry, distance from shore, distance from a settlement, distance from the protected area, presence/absence of aquaculture, distance from aquaculture, and wetland cover, we constructed a distribution model of fisheries using maximum entropy modelling. We conducted interviews with fishers asking about the frequency of grebe bycatch and conducted short‐term monitoring at various sites while conducting transect points for dead grebes.ResultsWe estimate 3270 km2 of the surface area of Lake Titicaca is used for fishing, which amounts to 39.40% of the lake's surface area. The area under the curve (AUC) of the distribution model was 0.89 and the True Skill Statistic was 0.67, which suggests maximum entropy modelling can model fisheries occurrence. The results of our interviews suggested a biologically implausible large number of grebes caught as bycatch annually. The cultural context of the interviews, including potential influences of non‐response and social‐desirability bias, being with fishers who often view the Titicaca Grebe as a nuisance species, might have caused over‐reporting of bycatch and hence led to these implausible figures.Main ConclusionsIt is possible to map fisheries using distribution models as one might with species. However, obtaining accurate measures of fisheries bycatch through interviews is more difficult, due to cultural factors which affect the accuracy in fisher's responses. While we hope that this method provides a low‐cost alternative to monitoring, it is not a suitable replacement for it.

Interactions between past societies and environmental change in the Lake Titicaca region (tropical Andes)

Interactions between past societies and environmental change in the Lake Titicaca region (tropical Andes)

Trends in the area of suitable breeding habitat for the Endangered Lake Titicaca Grebe Rollandia microptera, 2001–2020

Summary The Lake Titicaca Grebe Rollandia microptera is a poorly studied endemic species found in the Lake Titicaca watershed of Peru and Bolivia. Multiple surveys from the early 2000s indicated that the species was suffering a rapid population decline with an unknown cause. At the same time as these surveys, reports emerged that there was an increase in burning of the totora wetlands which are thought to be the primary habitat for the Lake Titicaca Grebe. However, since 2003, no work has been published either on the current population of the Lake Titicaca Grebe, or the extent of the totora wetlands in the Lake Titicaca region. This paper used satellite data to monitor the change in extent of habitat potentially suitable for the Lake Titicaca Grebe to determine whether habitat loss is likely to be a major driver of population declines in this species. We found that the extent of potentially suitable wetland remained stable between 2001 and 2020, though there are more local regional trends of change in extent of totora. We also found that multiple areas exist that might support Lake Titicaca Grebe populations, but where ornithological knowledge is lacking. We suggest no change to the IUCN status of the Lake Titicaca Grebe, but recommend that further fieldwork is required to monitor the species’ current population, especially in previously unstudied but potentially habitable areas.

Reconstructing two millennia of copper and silver metallurgy in the Lake Titicaca region (Bolivia/Peru) using trace metals and lead isotopic composition

Abstract Copper, silver, and gold exploitation has been a foundation of economic and socio-cultural development of Andean societies, at least for the last three millennia. The main centers of pre-colonial metallurgy are well-known from archeological artifacts, but temporal gaps inherent in this record handicap a finer understanding of the modalities of ore exploitation by succeeding civilizations. A continuous record over time of trace metals emitted during ore smelting operations make lake sediments excellent candidates to fill those gaps. Two millennia of metallurgy were reconstructed from atmospherically derived metals together with lead (Pb) isotope ratios in two dated sediment cores from Lake Titicaca. The first evidence for metallurgy is found during the apogee of the Tiwanaku state (AD 800–1150), with a higher copper (Cu) accumulation that can be attributed to the smelting of local Cu ores, based on Pb isotopic fingerprinting. During the Late Intermediate Period (AD 1150–1450), recorded peaks in metal deposition that persisted for ∼ twenty years show that mining activities were intensive but discontinuous. Pb isotope ratios suggest diversified extractive activities, mainly located in the southern part of the central Altiplano. Finally, the most intense mining epoch began during the Inca Empire (ca. AD 1500) and lasted until the end of the Colonial Period (AD 1830), with unprecedented metal deposition over this interval. Pb isotope fingerprinting shows that mining operations occurred mainly in the Lake Titicaca and Potosi areas and were responsible for metal emissions recorded in the entire Altiplano, as evidenced by other studies.

Revelations of ancient head shape: Cranial modification in the Cuzco region of Peru, Early Horizon to Inca Imperial Period.

Cranial vault modification (CVM), the intentional reshaping of the head, indicated group affiliation in prehistoric Andean South America. This study aims to analyze CVM data from the Cuzco region of Peru to illuminate patterns of early migration and settlement along with the later impact of the Inca Empire (AD 1438-1532) on the ethnic landscape. 419 individuals from 10 archaeological sites spanning over 2300 years were assessed for CVM using morphological analysis. CVM patterns show distinct temporal attributes: the tabular type of modification appeared first and dominated the early sample (900 BC-AD 600), followed by an influx of unmodified crania during the Middle Horizon (AD 600-1000). The annular type appeared later during the Late Intermediate Period (AD 1000-1438). In the subsequent period of Inca imperialism, modification rates were higher at sites in the Cuzco countryside than in Cuzco city sites. The study results, combined with archaeological and ethnohistoric data, reveal the sociopolitical transformations that occurred prior to and during the rise of the Inca Empire. The influx of unmodified crania during the Middle Horizon resulted at least partly from Wari occupation, while the appearance of the annular type during the LIP points to migration into the area, possibly from the Lake Titicaca region. In the Inca Imperial Period, Inca individuals at Cuzco city sites refrained from modification as a sign of their ethnic identity, while modification patterns in the Cuzco countryside likely reflect state-coerced resettlement of different ethnic groups.

Consistency of satellite-based precipitation products in space and over time compared with gauge observations and snow- hydrological modelling in the Lake Titicaca region

Abstract. This paper proposes a protocol to assess the space–time consistency of 12 satellite-based precipitation products (SPPs) according to various indicators, including (i) direct comparison of SPPs with 72 precipitation gauges; (ii) sensitivity of streamflow modelling to SPPs at the outlet of four basins; and (iii) the sensitivity of distributed snow models to SPPs using a MODIS snow product as reference in an unmonitored mountainous area. The protocol was applied successively to four different time windows (2000–2004, 2004–2008, 2008–2012 and 2000–2012) to account for the space–time variability of the SPPs and to a large dataset composed of 12 SPPs (CMORPH–RAW v.1, CMORPH–CRT v.1, CMORPH–BLD v.1, CHIRP v.2, CHIRPS v.2, GSMaP v.6, MSWEP v.2.1, PERSIANN, PERSIANN–CDR, TMPA–RT v.7, TMPA–Adj v.7 and SM2Rain–CCI v.2), an unprecedented comparison. The aim of using different space scales and timescales and indicators was to evaluate whether the efficiency of SPPs varies with the method of assessment, time window and location. Results revealed very high discrepancies between SPPs. Compared to precipitation gauge observations, some SPPs (CMORPH–RAW v.1, CMORPH–CRT v.1, GSMaP v.6, PERSIANN, and TMPA–RT v.7) are unable to estimate regional precipitation, whereas the others (CHIRP v.2, CHIRPS v.2, CMORPH–BLD v.1, MSWEP v.2.1, PERSIANN–CDR, and TMPA–Adj v.7) produce a realistic representation despite recurrent spatial limitation over regions with contrasted emissivity, temperature and orography. In 9 out of 10 of the cases studied, streamflow was more realistically simulated when SPPs were used as forcing precipitation data rather than precipitation derived from the available precipitation gauge networks, whereas the SPP's ability to reproduce the duration of MODIS-based snow cover resulted in poorer simulations than simulation using available precipitation gauges. Interestingly, the potential of the SPPs varied significantly when they were used to reproduce gauge precipitation estimates, streamflow observations or snow cover duration and depending on the time window considered. SPPs thus produce space–time errors that cannot be assessed when a single indicator and/or time window is used, underlining the importance of carefully considering their space–time consistency before using them for hydro-climatic studies. Among all the SPPs assessed, MSWEP v.2.1 showed the highest space–time accuracy and consistency in reproducing gauge precipitation estimates, streamflow and snow cover duration.

Enhanced mercury deposition by Amazonian orographic precipitation: Evidence from high-elevation Holocene records of the Lake Titicaca region (Bolivia)

Very few studies have focused on historical mercury (Hg) deposition in the Southern Hemisphere, especially for the pre-mining period. Therefore, the respective contributions of Hg emissions from anthropogenic and natural sources are not fully constrained and the long-term influence of climate variability is still in debate. In this study, we reconstructed Hg depositions over the last 13,500 years based on two sedimentary records located at the fringe between Amazonia and the Altiplano. Multiproxy analyses carried on the same sedimentary archives (i.e. Hg accumulation rates (AR), major elements, total organic carbon, δ13C and pollen analyses) show evidence that Hg deposition has risen according to Amazonian orographic moisture and precipitation during the Holocene, except for the last 200 years, for which modern industry and goldmining overwhelmed the natural signal. Comparisons with existing Hg records indicated that metallurgy and volcanic emissions were not perceptible due to the eastern down-wind position of the sites. Altogether, it argues that the historical variability of Hg deposition in the central eastern Andes has been primarily driven by changes in Amazonian moisture. At least six main phases of higher Hg AR (2.6 ± 1.4 μg m−2 y−1) compared to baseline values (0.9 ± 0.3 μg m−2 y−1) were identified over the Holocene. During the early and late Holocene, phases of higher Hg AR coincided with wet episodes recorded in Lake Titicaca and Sajama records. During the Middle Holocene arid phase, reconstructed wetter episodes by Hg together with vegetation dynamics were attributed to the set-up of moisture niches in the eastern flanks of the Andes. Comparisons to other paleoclimatic records supports the role of North Atlantic sea-surface temperature in forcing precipitation during the late Holocene period while other mechanisms allowing moisture niches by orography are discussed for the Mid-Holocene dry phase in the eastern Andes region.

The importance of traditional ecological knowledge in agroecological systems in Peru

ABSTRACTThis study argues that a critical element in the success of an ecosystem service (ES) approach at any level is the higher qualitative valuation of local traditional ecological knowledge (TEK). As such, the objectives of this research were to illustrate the role of TEK in agroecological systems in Peru and to develop recommendations about this type of knowledge acquisition. The data were gathered using interviews and focus groups with subsistence farmers along with key informant interviews to elicit TEK at local and regional scales in five provinces in the Lake Titicaca region of Puno, Peru. Qualitative analysis revealed dominant themes of TEK provided by farmers and key informants, and how this knowledge can enhance the application of an ES approach for environmental management. Climate variability, predicting the timing of seasonal changes, water availability, and adapting the agricultural calendar and agricultural techniques were all central themes. This research concludes that environmental management decisions in the Puno region of Peru are being informed and improved through the use of TEK. Supporting previous research, we propose that agroecological systems, at their core, need to respect the integrity and sanctity of TEK and value it properly within any practical solution for environmental resource management.EDITED BY John Parrotta

Instrumental neutron activation analysis of Inka and local pottery from northern Chile's Atacama Desert

This paper presents the results of bulk chemical compositional analyses of ceramic pastes through Instrumental Neutron Activation Analysis (INAA), which is the most precise method available for this kind of research. The analyses were carried out on 94 fragments of pottery from several archaeological sites in northern Chile's Atacama Desert. We aimed to examine the possible origins of pottery vessels distinguished by Inka and local styles within the process of the Inka State expansion into the territories south of Cusco, known as Collasuyu.On the basis of these analyses, we discuss the idea that the State introduced to the zone pottery with Inka iconographic styles from the Lake Titicaca region (more than 500km away). But, more important, the State seems to have encouraged the replication of State pottery standards by local artisans, who consciously or unconsciously maintained certain traditional procedures. This means that skilled local artisans imitated Inka iconographic style but using paste of local origin. These results show the importance of archaeometric analysis of high-prestige fine Inka and local pottery as it sheds light on how the State managed their political strategies, their impact on the prehistoric polities of northern Chile (NCh).

Prehistoric birds from the Lake Titicaca region, Bolivia: long-term continuity and change in an Andean bird community

From excavations at the Formative period (3,500 to 900 years old) Chiripa archaeological site on the southern shore of Lake Titicaca on the Bolivian altiplano (elev. 3,820 m), we identified 664 bones that represent 41 extant species of birds. Approximately 80% of the bones are from aquatic species such as coots, grebes, ducks, cormorants, and flamingos. Ten species from the bone sample (a grebe Podiceps occipitalis, cormorant Phalacrocorax brasilianus, goose Chloephaga melanoptera, duck Lophonetta specularoides, falcon Falco peregrinus, coots Fulica gigantea and F. leucoptera, dove Metriopelia aymara, owl Asio flammeus, and trogon Trogon personatus) were not recorded during rigorous bird surveys at Chiripa and elsewhere on the Taraco Peninsula in June-July 1996. One of these species (Trogon personatus) inhabits humid montane forest below 3,400 m elevation, and thus probably was transported by people to Chiripa from distances >80 km away. Each of the other nine species except Fulica leucoptera are known to occur regularly within the Titicaca Basin. The prehistoric data support the hypothesis that the regional composition of most continental Neotropical bird communities, in spite of many local range fluctuations, has been fairly stable over the past several millennia, a period of minor climate change compared to that of glacial-interglacial transitions. A challenge to researchers is to tease out the possible causes of local distributional changes in Neotropical birds, including an evaluation of how prehistoric people may have affected the presence and relative abundance of certain species. Received 3 September 2014. Accepted 27 February 2015.

ENSO impact on hydrology in Peru

Abstract. The El Niño and La Niña impacts on the hydrology of Peru were assessed based on discharge data (1968–2006) of 20 river catchments distributed over three drainage regions in Peru: 14 in the Pacific Coast (PC), 3 in the Lake Titicaca (TL) region, and 3 in the Amazonas (AM). To classify the El Niño and La Niña events, we used the Southern Oscillation Index (SOI) based on hydrological years (September to August). Using the SOI values, the events were re-classified as strong El Niño (SEN), moderate El Niño (MEN), normal years (N), moderate La Niña (MLN) and strong La Niña (SLN). On average during the SEN years, sharp increases occurred in the discharges in the north central area of the PC and decreases in the remaining discharge stations that were analyzed, while in the years of MEN events, these changes show different responses than those of the SEN. During the years classified as La Niña, positive changes are mostly observed in the majority of the stations in the rivers located in the center of Peru's Pacific Coast. Another important result of this work is that the Ilave River (south of the Titicaca watershed) shows higher positive (negative) impacts during La Niña (El Niño) years, a fact that is not clearly seen in the rivers of the northern part of the Titicaca watershed (Ramis and Huancane rivers).

Role of Genetic Modification in Developing Climate Smart Agriculture to Ensure Sustained Food Security

I was a contemporary of James Watson and Francis Crick at the University of Cambridge, UK, during 1950–52. I was aware of the fact that they were working on the molecular structure of DNA in association with Maurice Wilkins and Rosalind Franklin since I used to visit the Cavendish Laboratory to attend lectures by Prof Max Perutz. Their publication on the double helix structure of the DNA molecule appeared in Nature early in 1953 [2, 7, 8]. I was then at the Genetics Laboratory of the University of Wisconsin, Madison, USA. Since then, I have been following the explosive progress of the science of molecular genetics, opening up uncommon opportunities for transferring genes across sexual barriers. I was deeply interested in this development, since my work in the early 1950s related to the transfer of genes in tuber-bearing Solanum species for characters like frost tolerance and resistance to the golden nematode, Heterodera rostochiensis. The donor for frost tolerance was the species S. acaule from the Lake Titicaca region of Peru-Bolivia, while the donor for golden nematode resistance was S. polyadenium. Achieving crosses between these species and S. tuberosum was extremely difficult, since the foreign pollen were getting inhibited in the stigma and style. I had to remove the stigma and replace it with an artificial medium which promoted pollen germination [4]. This technique later came to be known as the ‘Swaminathan artificial stigma method’. All this would not have been necessary if the recombinant DNA technology had existed then. Thus, the Watson–Crick–Wilkins– Franklin discovery paved the way for fulfilling the dream of plant and animal breeders and microbiologists with respect to producing novel genetic combinations of applied interest. The award of the Nobel Prize to my colleague at the University of Wisconsin Dr. Joshua Lederberg, for his work on microbial transformation further stimulated my interest in this fast growing area of science. The US National Academy of Sciences invited me in 1982 to deliver a lecture on ‘Biotechnology Research and Third World Agriculture’, where I emphasised the need for Third World countries, to master all recent developments in Genetics [5]. In 1980, when I joined the Union Planning Commission at the invitation of the then Prime Minister of India Mrs. Indira Gandhi, I got a National Biotechnology Board set up to achieve synergy and coordination among the work in progress in molecular genetics and genetic engineering under the umbrella of different scientific organisations like ICAR, CSIR, ICMR, Department of Atomic Energy and UGC. I served as the first chair of the National Biotechnology Board. Later, it was converted into a Department of Biotechnology during the tenure of Prime Minister Rajiv Gandhi, with Dr. S. Ramachandran serving as its first Secretary. During the last 30 years, the Government of India has invested a considerable amount of money in creating the infrastructure essential for advanced research in the broad

Herpetofaunal Remains from Khonkho Wankane, an Urban and Ceremonial Centre in the Southern Lake Titicaca Altiplano: Unique Behavioural Correlates to Osseous Taphonomy

This research reports the herpetological (reptile and amphibian) remains from Khonkho Wankane, an urban and ceremonial centre in the southern Lake Titicaca region of the Bolivian Altiplano, which fluoresced during the Late Formative period. The total n = 1710, including a minimum of six taxa and representing a significant portion of the relatively depauperate modern herpetofauna recorded for the Lake Titicaca area. A lizard of the genus Liolaemus (Tropiduridae) was identified. Amphibians are represented by Andean toad Rhinella spinulosa (Bufonidae) and by at least four taxa of frogs: [cf. Gastrotheca marsupiata (Hylidae) and Pleurodema marmorata or P. cinerea and Telmatobius spp. (Leptodactylidae)]. The latter genus does not include members of the giant variants (T. culeus) that dwell in Lake Titicaca. The question of how these remains were incorporated into the site deposits is examined taphonomically. No indicators of human or small carnivore predation were detected. Significant spatial clustering of amphibian remains was detected, with two clusters contributing n = 1562 or 92.4% of the amphibian total (n = 1690). These concentrations also are characterised by a depressed ratio of cranial versus postcranial elements, which cannot be explained by recovery methods. These concentrations of herpetofaunal remains likely represent in-burrow deaths of species sheltering for thermoregulatory benefits away from this harsh Altiplano environment, with the lowered recovery of cranial elements hypothesised to have resulted from a lack of ossification. The bulk of herpetofaunal remains recovered therefore likely were recent intrusions into the site deposits and do not represent the residue of human exploitation during the occupation of Khonkho Wankane. Copyright © 2011 John Wiley & Sons, Ltd.

Climatic Influence on Sedimentology and Geomorphology of the Rio Ramis Valley, Peru

Abstract Fluctuations in regional precipitation and in base-level (the level of Lake Titicaca) trigger changes in fluvial erosion and deposition in the largest tributary valley of Lake Titicaca, the Rio Ramis, Peru. Relationships between fluvial sedimentation and terrace formation demonstrate that large-scale aggradational and downcutting events are associated with specific regional climatic events that have been previously documented in the Lake Titicaca basin and elsewhere on the Altiplano. Five laterally extensive terrace tracts (A through E) are present within the valley. Downcutting of the Ramis valley is correlative with base-level (Lake Titicaca level) fall caused by a decrease in precipitation. Aggradation is correlative with base-level rise during increasing precipitation. Sedimentary facies underlying the terraces record deposition in a large paleolake followed by deposition of both meandering and braided fluvial sediments. The highest terrace in the valley—E—is underlain by a thick sequence of lacustrine strata that was deposited during an extremely wet period in the Lake Titicaca region that terminated at about 40,000 cal yr BP. These lacustrine strata were subsequently downcut, likely at a time of large drop in lake-level, resulting in a deeply incised valley. The main phase of fluvial aggradation in the valley (sediments underlying the D through B terraces) was slow, spanning about 25,000 years. It occurred before, during, and after the Last Glacial Maximum (from before 35,140 ± 790 cal yr BP until about 10,421 ± 181 cal yr BP), a time period that was mostly characterized in the Lake Titicaca basin by high precipitation rates and high base-levels. The aggradation resulted in almost 40 m of sediment accumulation in the valley and was followed by rapid (about 2,000 years), but episodic, incision into the underlying fluvial sediments to form the C and B terraces, as well as the erosional surface beneath the modern fill terrace (A). This erosional phase corresponded to several periods of local base-level (Lake Titicaca) lowering between 10,241 ± 181 and 1,668 ± 76 cal yr BP. The modern fill terrace has aggraded about 2 m above modern river level, likely within the last 1,500 years.

Evidence for Early Long-Distance Obsidian Exchange and Watercraft Use from the Southern Lake Titicaca Basin of Bolivia and Peru

Excavations at two sites on the Island of the Sun in Lake Titicaca, called Ch'uxuqullu and Titinhuayani, discovered significant preceramic (ca. 2000 B. C.) through Formative period (up to ca. A. D. 400) occupations. Excavation data indicate that there was a continuous occupation from the first known settlements on the island up to the present day. The early occupations on the island were culturally linked to the populations on the mainland, as indicated by ceramic analysis and the presence of nonlocal obsidian from the Colca Valley source, 275 km to the northwest. Our excavation data also reveal that there was a brisk exchange network between the island and mainland beginning at least during the Formative period, and probably earlier during the end of the Late Archaic period. Furthermore, paleoenvironmental data indicate that the island has been isolated from the mainland during most or all of the human occupation. The Lake Titicaca region of Peru and Bolivia was characterized by a system of exchange that relied, in part, on watercraft beginning at least by 1600 B. C.

Modelling nocturnal heat dynamics and frost mitigation in Andean raised field systems

The raised fields system is an old technique of soil and water management dating back to prehispanic time. Very common in the Lake Titicaca region, it essentially consists of a series of earth platforms on which crops are grown, surrounded by water canals connected to inlet and outlet ditches. An important and widely recognised benefit of this system of management is its contribution to frost mitigation during the growing season. A physical process-based model is presented to explain the role played by the canals in the nocturnal heat dynamics and the cold mitigation process. Adapted from a two-layer transfer scheme (Shuttleworth–Wallace type) with a vegetation layer and a substrate layer representing the canals, the model shows that greater heat flux emanating from the canals and greater water condensation on the crop both contribute to the mitigation effect. Model outputs are compared with experimental data collected on a system of raised fields in the Lake Titicaca region. Crop temperature appears to be correctly estimated and more accurately than water temperature. When used in a predictive way, the model shows that wider canals or narrower platforms have a positive impact on the minimum crop temperature reached during the night. Increasing water depth also improves frost mitigation, but conversely, a deeper canal (with the same level of water) has a negative impact. Leaf area index (LAI) and crop height, both have a positive impact. Higher wind velocity or higher air relative humidity also enhances the frost mitigation effect.

Reviews

The Geographical JournalVolume 166, Issue 3 p. 267-281 Reviews First published: 05 July 2005 https://doi.org/10.1111/j.1475-4959.2000.tb00026.xAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinked InRedditWechat Abstract Borneo: Jewel in a Jade Rainbow. By David and Sue Fielding. People, Land and Time: an historical introduction to the relations between landscape, culture and environment. Edited by Peter Atkins, Ian Simmons and Brian Roberts. Solid Waste Management: Critical Issues for Developing Countries. Edited by Eltzabeth Thomas-Hope. Ecoregions: the Ecosystem Geography of the Oceans and Continents. By Robert C. Bailey. Ecohydrological response modelling: predicting plant species’ response to changes in site conditions(in English with Dutch summary). By A.C.D. Ertsen. Agrarian Reform in Theory and Practice: a study of the lake Titicaca region of Bolivia. By Jane Benton. Debt and Adjustment: Social and Environmental Consequences in Jamaica. By Patricia Lundy. Swidden Farming and Fallow Vegetation in Northern Thailand. By Dietrich Schmidt-Voct. Sustainability: Life Chances and Livelihoods. Edited by Michael Redclift. Tropical Pacific Island Environments. By Christopher S. Lobban and Maria Schefter. Beyond El Niiio: decadal and inter-decadal climate variability. Edited by Antonio Navarra. Public Purpose or Private Benefit? The Politics of Energy Conservation. By Gill Owen. Sudan's Predicament: Civil War, Displacement and Ecological Degradation. Edited by Girma Kebbede. Shock-Shift in an Enlarged Europe: The geography of socio-economic change in East-Central Europe after 1989. Edited by F.W. Carter and W. Maik. Miombo Ecology and Management: an introduction. By E.M. Chidumayo. Weather and Climate (CD Rom). By Harald Frater. The Bankruptcy of Economics: Ecology, Economics and the Sustainability of the Earth. By Joseph Wayne Smith, Graham Lyons and Gary Sauer-Thompson Edited by David Harper and Tony Brown. Precision Agriculture: Spatial and temporal variability of environmental quality (Ciba Foundation Symposium 210). Edited by John V. Lake, Gregory R. Bock and Jamie A. Goode. The Road to Egdon Heath: the Aesthetics of the Great in Nature. By Richard Bevis. Secure From Rash Assault: Sustaining the Victorian Environment. By J. Winter. Coastal defence and Earth Science conservation. Edited by Janet Hooke. Human Geography Today. Edited by Doreen Massey, John Allen and Philip Sarre. Volume166, Issue3September 2000Pages 267-281 RelatedInformation

Heat and moisture dynamics in raised field systems of the lake Titicaca region (Bolivia)

Pre-Hispanic cultures constructed more than 82 000 ha of raised fields for agricultural production in the Lake Titicaca Region, in the current day Bolivia and Peru. Raised fields consist of platforms (up to 1.2 m high and 2–20 m wide), elevated relative to the original soil surface and surrounded by canals (1.6–4.5 m wide). In the last decade, archaeologists have promoted the adoption of raised fields among local farmers as a way to reduce potato ( Solanum tuberosum) crop damage caused by mid-growing season frosts in the Altiplano (3800–4000 m above sea level). The objective of the present research was to obtain experimental information on a number of processes that might contribute to the frost mitigation effect. Field experiments were conducted at two sites in the Bolivian Altiplano. Temperature and moisture measurements were made in plots where potato crops were grown. Minimum temperatures during clear nights with fairly calm wind conditions were about 1°C higher at 50 cm above the soil surface in the middle of raised field platforms compared to adjacent flat fields, confirming earlier reports. Differences in minimum temperatures tended to increase with wider canals, whereas a change of platform width from 4 to 6 m had no appreciable effect. Temperature and moisture distributions in platform/canal cross sections suggest that the frost mitigation effect is due mostly to above-ground processes. Specifically, air circulation from canal to platforms, arising from natural convection, and cold air drainage back to the canals satisfactorily account for observed temperature differences. These results should prove useful in the design of raised fields and of physical process-based models to simulate the frost mitigation effect.

Land Reform and Its Effect upon Production and Productivity in the Lake Titicaca Region: Comment

In reply to Juan Felipe Scott's comment on my article,' let me first of all say that he is eminently correct that there were some important omissions that warrant consideration regarding land reform in Bolivia and Peru. Social, political, and cultural variables were largely absent from the article.2 However, the paper was not intended to be a comprehensive presentation of all aspects and issues related to land For that reason, as its title explicitly states, it was restricted to Land Reform and Its Effect upon Production and Productivity... . Scott claims that I failed to distinguish between jure and de facto reform. In reply, I can only quote from the article:

Land Reform and Its Effect upon Production and Productivity in the Lake Titicaca Region: Reply

Land Reform and Its Effect upon Production and Productivity in the Lake Titicaca Region: Reply