Extreme Temperature Fluctuations Research Articles

Hydromulch Application to Bare Soil: Soil Temperature Dynamics and Evaporative Fluxes

Core Ideas Hydromulch was applied to disturbed, bare soil at two rates. Micro‐Bowen ratio systems quantified soil temperature and evaporation. Hydromulch moderated temperature fluctuations, especially daily maximums. Hydromulch application reduced evaporation following rainfall. North Dakota State Univ., Dep. of Soil Science, Fargo, ND 58108. Soil disturbance reduces plant‐residue cover and can leave bare soil susceptible to erosion, extreme temperature fluctuations, and increased evaporation. Under such conditions, establishing vegetation is difficult. To overcome these difficulties, managing disturbed lands by applying surface cover may be a good step toward soil reclamation. Hydromulch is often applied to stabilize soil after disturbance, but its influence on soil temperature and evaporation has not been described. This study assessed soil temperature over time and used the surface energy balance to quantify evaporation from bare soil (0×), and two rates of hydromulch application, 1× and 3× (by weight) of manufacturer's recommended rate. Diurnal temperature extremes were highest in the 0× and least in the 3×. Evaporation was highest in the 0× during the final 18 d of data collection and lowest in the 3×. These findings indicate that temperature fluctuations decrease and evaporation is reduced when hydromulch is applied to bare soil, suggesting it may aid in soil reclamation.

Regional variation in Holocene climate quantified from pollen in the Great Plains of North America

ABSTRACTThe Great Plains experienced extreme fluctuations in precipitation and temperature throughout the Holocene, but these fluctuations have been difficult to quantify systematically across the region. Pollen has long been used as a proxy for reconstructing climate changes, but its power is limited if a region is devoid of modern pollen samples to facilitate comparison with known climate conditions. Here, we present a set of pollen‐climate transfer functions developed using weighted‐averaging partial least squares to reconstruct mean annual precipitation (MAP), mean temperature of the coldest month (MTcold) and mean temperature of the warmest month (MTwarm). At the foundation of these transfer functions is a new set of 141 modern pollen samples that specifically cover the climate space of the Great Plains. These functions quantify the relationship between pollen assemblages and modern climate in this region (r = 0.928, 0.838 and 0.897 for MAP, MTcold and MTwarm, respectively). We applied these functions to three previously established pollen records taken from lacustrine sites in the region – Fox Lake, MN; Moon Lake, ND; and Kettle Lake, ND – to reconstruct precipitation and temperature at these sites throughout the Holocene. Annual precipitation reconstructed with these transfer functions at Moon Lake and Kettle Lake does not capture a severe, prolonged period of drought during the mid‐Holocene as seen in many other proxy records from these sites and from the region. Reconciliation of these results involves both the autecology of Ambrosia and the inability of any pollen surface samples to capture seasonal and short‐term variability in precipitation. Thus, the transfer functions correctly reconstruct periodic wet summers and a disturbance factor favouring Ambrosia, but miss the effects of reduced winter precipitation and increased frequency of severe drought. The problem revealed here may be more general to biomes with higher frequency disturbance regimes and more weedy species.

Health status of corals surrounding Kish Island, Persian Gulf.

Corals in the Persian Gulf exist in a harsh environment with extreme temperature and salinity fluctuations. Understanding the health of these hardy corals may prove useful for predicting the survival of other marine organisms facing the impacts of global climate change. In this study, the health state of corals was surveyed along belt transects at 4 sites on the east side of Kish Island, Iran. Corals had a patchy distribution, low colony densities and species diversity, and were dominated by Acropora, Porites, and Dipsastrea. We found chronic sedimentation on corals, a high prevalence of old partial mortality, abundant bioeroders, and overgrowth of corals by sponges and bryozoans. These are all signs indicating suboptimal environmental conditions for coral reefs. Four types of tissue loss lesions consistent with disease were found: Porites multi-focal chronic tissue loss, Porites peeling tissue loss, Porites focal chronic tissue loss, and Dipsastrea focal sub-acute tissue loss. Overall disease prevalence was 3.6% and there were significant differences in prevalence among the 3 most abundant coral genera. Acropora was numerically dominant within transects yet showed no signs of disease, whereas Porites had a 14% disease prevalence, indicating differential susceptibility to disease among genera. Other coral lesions included pigmentation response in Porites associated with algae invasion or boring organisms, sponge overgrowth, and mucus sheathing in Dipsastrea. The Persian Gulf region is understudied, and this represents one of the first quantitative surveys of coral health and disease on these reefs.

Behavior of Telenomus podisi (Hymenoptera: Platygastridae) Adults under Overwintering Conditions

Abstract To assess overwintering refuge preferences by Telenomus podisi Ashmead, artificial refuges of varying geometries and composition were provided to wasps when exposed to overwintering conditions in an environmental chamber. Field sampling of leaf-litter and tree bark was also used in an effort to determine site preference of overwintering wasps. Under artificial overwintering conditions, wasps preferred to hang inverted while quiescent, regardless of the refuge design, indicating behavior that avoids precipitation or extreme temperature fluctuations during overwintering in field conditions. Wasps preferred refuges with wider gaps between upper and lower surfaces, avoiding spaces that were narrower than their standing height. Parasitoids also preferred settling at least 60 mm from refuge edges. Results suggest that T. podisi has a preference for the type of overwintering refuge that leaf-litter may offer.

Global and quantum risks of extreme temperature fluctuations in Moscow

The article discusses topical problems of legal support for construction activities in relation to global climate change. Therefore, the results of high-resolution studies were treated. These studies tracked the pattern of fluctuation intensity changes of maximum and minimum temperatures in Moscow in the period of 1973 to 2009. The article highlights methodology elements for the statistical analysis of technical risks for implementing extreme temperature loads. A quantitative predictive risk assessment of extreme high and low temperatures and thawing risks for the entire life cycle of buildings are given. These estimates are intended to take account of the thermal loads on the ecological systems of urban areas as well as to design buildings and engineering systems that form microclimate of premises. The paper presents for the first time the obtained by the authors and previously unknown quantum regularities of the air temperature variations in the surface layer of the atmosphere. It also contains graphic materials for statistical studies of the fluctuation intensity evolution of maximum and minimum daily temperatures in the city of Moscow.

RESPONSE OF MICROALGAE IN A CHANGING CLIMATE AND ENVIRONMENT

Microalgae are ecologically important as a major primary productivity driver via photosynthetic carbon fixation. As the primary producers and food sources for higher trophic organisms, microalgae play a crucial role in maintaining the equilibrium of food webs in the aquatic ecosystem. The current shifts of global climate due to anthropogenic release of greenhouse gases have been reported to pose numerous impacts on microalgae. Extreme fluctuations in atmospheric temperature, light intensity, ultraviolet (UV) radiations, carbon dioxide (CO2) levels, and salinity can lead to alterations in growth, disruption of homeostasis, photosynthetic rate, respiration, enzymatic activity, protection to oxidative damage, and trophic transfer in microalgae. Various studies on microalgal responses to these environmental changes are ongoing to provide a deeper insight into the relationship between microalgal growth, metabolic adjustment and community structure. In this review the authors aim to highlight the recent findings on the responses of microalgae in the changing environment. Keywords: microalgae, climate change, environmental factors

Ecology and Environmental Challenges of the Persian Gulf

The extreme salinity and temperature fluctuations of the Persian Gulf waters have created unique marine and coastal ecosystems, with numerous benefits to Iran and neighboring countries. However, human activities, including rapid coastal development, land-based pollution, oil and gas extraction, and shipping, are threatening the survival of these ecosystems. With long shorelines, a large coastal population, and locally important fisheries and tourism-related jobs, Iran has a lot at stake in the degradation of its marine and coastal environments. However, it is not too late to put a stop to further degradation. This article recommends a number of targeted actions at the local, national, and regional levels to address the threats to the Persian Gulf ’s environment and protect this important renewable resource.

Abstraction techniques to improve scalability of equivalence verification for NCL circuits

Asynchronous NULL convention logic (NCL) circuits are dual-rail quasi-delay-insensitive circuits that have many applications in high radiation and extreme temperature fluctuation environments such as space exploration. Two abstraction techniques are proposed that can be used to drastically improve the efficiency and scalability of formal equivalence verification targeted at NCL circuits. The effectiveness of the abstraction techniques have been demonstrated using a number of multiply and accumulate circuit benchmarks.

Caddisfly behavioral responses to drying cues in temporary ponds: implications for effects of climate change

Aquatic organisms that live at high latitudes and elevations are especially vulnerable to climate-change-induced alterations in snowpack, snowmelt, and evaporation rates, all of which affect basin filling and drying dates. Extraordinarily early drying events in shallow ponds and wetlands at our study sites prompted us to conduct 2 mesocosm experiments to document how proximate cues of drying modify agonistic behaviors among larvae of the caddisfly, Asynarchus nigriculus. Larvae are mainly detritivores but can be extremely aggressive and engage in mob cannibalism, perhaps to obtain a dietary supplement that hastens escape from drying basins. In one experiment, we manipulated caddisfly density to simulate the effects of crowding during pond drying. In a 2nd experiment, we reduced water levels and manipulated a protein supplement that mimics the dietary benefits of cannibalism. We quantified the effects of those manipulations on aggressive behaviors that are precursors to cannibalism and on development time to pupation. Frequency and duration of agonistic encounters increased as a function of larval density and, independent of density, were higher in drying than nondrying treatments, especially in the absence of a protein supplement. Pupation occurred earlier in high- than low-density treatments and earlier with than without a protein supplement. In contrast, the timing of pupation was not accelerated in drying compared with nondrying treatments, which might reflect the extreme diel temperature fluctuations in drying ponds, hence suboptimal growth conditions. Our findings provide evidence that declining water levels and crowding serve as cues that enable caddisflies to adjust behavior and development in the face of habitat drying. Early drying events observed in recent years may exceed the limits of this flexibility and portend the demise of populations in temporary habitats that historically supported this species.

Hettangian tetrapod burrows from the continental Steierdorf Formation at Anina, western Romania

Very large, sparsely distributed, sinuous, gently dipping and occasionally branching tunnels with subordinate swells, as well as possible chambers and scratches, are described from the Hettangian Dealul Budinic Member of the Lower Jurassic continental Steierdorf Formation at Anina in the South Carpathians, Romania, and are interpreted as tetrapod burrows. No bone remains have been found in association with these structures. The morphology and large dimensions of the burrows suggest that the trace-makers were sauropsid amniotes, most probably either crocodyliforms or small-sized basal neornithischian dinosaurs, although their therapsid affinities, despite being less likely, cannot be discarded either. The age, large size and probable origin of these burrows add important information to a poorly documented period of the evolution of tetrapod fossoriality. It may be suggested that within a relatively short time interval following the Triassic-Jurassic extinction event, when environmental conditions were still marked by strongly seasonal climate with prolonged droughts as well as extreme moisture and temperature fluctuations, fossorial habit probably became yet again an endurance strategy for burrow makers.

Breeding blueberries for a changing global environment: a review.

Today, blueberries are recognized worldwide as one of the foremost health foods, becoming one of the crops with the highest productive and commercial projections. Over the last 100 years, the geographical area where highbush blueberries are grown has extended dramatically into hotter and drier environments. The expansion of highbush blueberry growing into warmer regions will be challenged in the future by increases in average global temperature and extreme fluctuations in temperature and rainfall patterns. Considerable genetic variability exists within the blueberry gene pool that breeders can use to meet these challenges, but traditional selection techniques can be slow and inefficient and the precise adaptations of genotypes often remain hidden. Marker assisted breeding (MAB) and phenomics could aid greatly in identifying those individuals carrying adventitious traits, increasing selection efficiency and shortening the rate of cultivar release. While phenomics have begun to be used in the breeding of grain crops in the last 10 years, their use in fruit breeding programs it is almost non-existent.

Thermal refugia in cleared temperate Australian woodlands: Coarse woody debris moderate extreme surface soil temperatures

Extensive tree clearing and agriculture has exposed surface soils of former Australian temperate woodlands to more extreme temperature fluctuations. Given the highly variable climate in these regions, and increasing temperature overall, amelioration of extreme surface soil temperatures would have implications for soil-dependent biological activity. Reintroduction of coarse woody debris (CWD) to these woodlands may moderate surface soil temperatures. Diurnal surface soil temperatures at a depth of 2.5cm were monitored during summer and winter at different distances from CWD with varying diameters. CWD samples were located beyond the edge of neighbouring tree canopies. The result of the initial analysis showed that CWD reduced the durations of time at extremely high summer and low winter surface soil temperatures. Soil temperatures near CWD were largely maintained below the summer high of 30°C and above the winter low of 5°C. The duration of time above 30°C in summer was reduced by 93% near CWD and the duration of time below 5°C in winter was reduced by 77%, compared with reference distances. Simple nonlinear statistical models were developed to explain the observed daily summer maximum and winter minimum surface soil temperatures as functions of distance from CWD and CWD diameter. The forms of these models reflected different dominant physical processes in each season. Mean summer daily maximum surface soil temperatures were significantly cooler by 11.1°C and mean winter daily minimum temperatures were significantly warmer by 1.9°C near CWD compared to the respective mean maximum and minimum temperatures at reference distances. Increasing CWD diameter increased the range of the impact over distance from CWD in both summer and winter. During the summer maxima, larger diameter CWD also increased the magnitude of the reduction in surface soil temperature near CWD. The results of this study demonstrate that CWD can be effective in protecting surface soils from sustained exposure to extreme surface soil temperatures. Therefore, at a landscape scale, CWD could create thermal refuges better suited to soil-dependent biological activity, such as for the germination and growth of the plant understorey in woodlands. This impact of CWD may be valuable for supporting understorey productivity and diversity in cleared lands.

Cochliobolus lunatus colonizes potato by adopting different invasion strategies on cultivars: New insights on temperature dependent-virulence

Extreme temperature fluctuations affect the interaction dynamics of Cochliobolus lunatus through temperature-dependent virulence, virulence differentiation and induced-virulence which poses a major threat to global food security. The relationship between higher temperature and pathogenicity of C. lunatus on reported hosts are poorly understood. In this study, temperature stress was applied on C. lunatus to investigate the correlation among the different types of conidia. Additionally, a comparative dissection of the invasion process, infection structures and conidial germination pattern on four different Solanum tuberosum L. (potato) cultivars were performed. Based on microscopic examination, it was found that C. lunatus adopts different hyphae morphology and septation pattern at different temperature regimes and produce different types of conidia. The study showed that four-celled conidia are overproduced at elevated temperature (>30 °C) than one, two, three and five-celled conidia. Our finding revealed that C. lunatus conidia exhibit bipolar germination (>14.67%, P<0.05), unipolar germination (>35.33%, P<0.05), penetrate subcutaneously via epidermal anticlinal cell wall (>0.33%, P < 0.05) and differentially form appressoria-like structures during colonization of four different potato cultivars. Importantly, it is shown that unipolar germination and bipolar germination in C. lunatus are independently occurring phenomenon irrespective of the host. It is confirmed that C. lunatus adopt different but highly successful strategies on four different potato cultivars to incite brown-to-black leaf spot disease. Altogether, our data showed that increase in temperature enhances C. lunatus virulence on different potato cultivars irrespective of their inherent thermotolerant traits.

The power of comparison

central nervous system and sensory inputs are essential for coordinated movement. Studies of central pattern generators have influenced profoundly the way we think about neurons, neuronal networks and their functional properties. It is clear, for example, that neuronal circuits can be reconfigured through the action of neuromodulatory neurons to produce a variety of outputs, and that intrinsic membrane properties of neurons are subject to homeostatic regulation. In this special issue, Marder and colleagues describe the effects of temperature on motor patterns generated by the stomatogastric nervous system of the crab, Cancer borealis, and consider how neuronal networks and the output they generate remain stable in the face of extreme temperature fluctuations. Temperature is a central focus also of the contribution from Xu and colleagues who consider the sophisticated mechanisms that have evolved to enable animals to sense and adapt to changes in temperature. In their review, these authors present a strongly comparative viewpoint, and their discussion offers fascinating insights into the effects of temperature on aging and longevity. Homeostasis, as an overarching theme, is central also to the contribution by Keene and colleagues, who discuss how the brain of the fruit fly modulates sleep and how sleep in this insect, and in other animals, is influenced by metabolic state. Insects have a long history in the study of sleep. Cockroaches, for example, were used to provide the first demonstration that animals show compensatory mechanisms after sleep loss (Campbell and Tobler, Neurosci Biobehav Rev 8:269–300, 1984), and the genetic mechanisms that underlie sleep and sleep disorders are now being investigated extensively using the fruit fly, Drosophila. Callaerts and colleagues use Drosophila to provide insights into the importance of glia in normal brain function. They explore what is, and what is not, known about This special issue celebrates excellent examples of invertebrate neuroscience. It has its origins in the Cold Spring Harbor Asia (CSHA) Conferences on invertebrate neurobiology held recently in Suzhou, China, and is designed to provide a ‘taster’ of some of the exciting works presented at these meetings. There are of course very many aspects of invertebrate neurobiology that have seen remarkable advances in recent years. This issue highlights a small number of interesting examples. The topics are as diverse as they are interesting, and illustrate well the excitement that exists in current invertebrate neuroscience. For many years, there has been intense interest in the neuronal circuits (central pattern generators, CPGs) that produce rhythmic motor patterns supporting activities such as feeding, walking, swimming, and breathing. Sakurai and Katz discuss the unique perspective that the study of gastropod CPGs brings to this field. One important emerging concept is that different and independently evolved circuits using the same set of neurons can generate the same behavior. Their contribution to this special issue illustrates beautifully the power of a comparative approach. This theme is expanded upon by Ayali and colleagues who discuss recent work on an important model of legged locomotion, the cockroach, Periplaneta americana. In their review, they emphasize that motor system activity is modulated by sensory information and that dynamic interactions between the

Dynamic Simulation of the Green Roofs Impact on Building Energy Performance, Case Study of Antananarivo, Madagascar

Green roofs improve building energy performance and constitute an alternative to sustainable buildings. A green roof model is dynamically coupled with a building thermal model to assess its energy performance that takes into account the indoor air temperature dynamic changes. Under the climate conditions in Antananarivo, we compared green and conventional roofs. The present study shows that green roofs protect the roof structure under extreme temperature and large temperature fluctuations. For the case of Antananarivo, the amplitude of the temperature fluctuations at the top face of the support is reduced by 28 °C when using green roof. The impact of the green roof on indoor air temperature and energy demand is investigated. The vegetation decreases the maximum indoor air temperature and improves the building thermal comfort during summer days. It has no effect on the minimum indoor air temperature, but additional soil thickness can increase it. In addition, a global sensitivity analysis, which is carried out on the proposed model without considering any specific weather data, allows us to identify the most influential parameters on the energy demand. It has been found that green roofs have almost insignificant thermal impact in insulated buildings; however, their potential prevails over the building envelope and weather characteristics in the case of non-insulated building.

Vascular plants at extreme elevations in eastern Ladakh, northwest Himalayas

Background: Due to the dry continental climate, the mountains of eastern Ladakh are unglaciated up to 6200–6400 m, with relatively large areas of developed soils between 5600 and 6000 m covered by sparse subnival vegetation. However, there are no studies on the composition of plant assemblages from such extreme elevations, their microclimates, vertical distributions and adaptive strategies.Aims: The subnival vegetation was described and the relationship between microclimate, species distribution and species functional traits was analysed.Methods: In total, 481 vegetation samples from 91 permanent plots, a floristic database of Ladakh and extensive microclimate measurements were used. Measurements of 15 functional traits were made and their relationship with species distribution between 4600 and 6150 m was tested.Results: The subnival zone was characterised by extreme diurnal temperature fluctuations, a short growing season (between 88 and 153 days) and low soil temperature during the growing season (between 2.9 °C and 5.9 °C). It hosted 67 species, mainly hemicryptophytes, and ranged from ca. 5600 m to the highest known occurrence of vascular plants in the region (6150 m). The most common plant families were Brassicaceae, Asteraceae, Poaceae, Fabaceae and Cyperaceae. Subnival specialists with narrow elevational ranges represented 42% of the flora; these species were shorter, had relatively higher water content and water-use efficiency and contained more nutrients and soluble carbohydrates than species with a wider elevational range.Conclusions: The subnival vegetation of eastern Ladakh is dominated by generalist species with wide vertical ranges and not by high-elevation specialists. These findings, in view of the vast unglaciated areas available for range extension, suggest a relatively high resilience of the subnival flora to climate change in this region.

Gene expression changes controlling distinct adaptations in the heart and skeletal muscle of a hibernating mammal.

Throughout the hibernation season, the thirteen-lined ground squirrel (Ictidomys tridecemlineatus) experiences extreme fluctuations in heart rate, metabolism, oxygen consumption, and body temperature, along with prolonged fasting and immobility. These conditions necessitate different functional requirements for the heart, which maintains contractile function throughout hibernation, and the skeletal muscle, which remains largely inactive. The adaptations used to maintain these contractile organs under such variable conditions serves as a natural model to study a variety of medically relevant conditions including heart failure and disuse atrophy. To better understand how two different muscle tissues maintain function throughout the extreme fluctuations of hibernation we performed Illumina HiSeq 2000 sequencing of cDNAs to compare the transcriptome of heart and skeletal muscle across the circannual cycle. This analysis resulted in the identification of 1,076 and 1,466 differentially expressed genes in heart and skeletal muscle, respectively. In both heart and skeletal muscle we identified a distinct cold-tolerant mechanism utilizing peroxisomal metabolism to make use of elevated levels of unsaturated depot fats. The skeletal muscle transcriptome also shows an early increase in oxidative capacity necessary for the altered fuel utilization and increased oxygen demand of shivering. Expression of the fetal gene expression profile is used to maintain cardiac tissue, either through increasing myocyte size or proliferation of resident cardiomyocytes, while skeletal muscle function and mass are protected through transcriptional regulation of pathways involved in protein turnover. This study provides insight into how two functionally distinct muscles maintain function under the extreme conditions of mammalian hibernation.

Interfacial heat transfer through a natural protective fibrous architecture: a wild silkworm cocoon wall

The wild Antheraea pernyi silkworm cocoon is a thin and light-weight structure, yet it has shown effective thermal insulation characteristics against extreme temperature fluctuations, which meet the demands of humans for lighter materials with higher thermal resistance. We present a two-dimensional computational fluid dynamics model of this unique fibrous cocoon structure to simulate the heat transfer process through the cocoon wall. The model is able to predict the temperature field inside the cocoon reasonably well. The results of the model also show that the mineral crystals present in the outer layers of the Antheraea pernyi cocoon can increase air flow resistance and decrease the effect of natural convection, which further reduces the heat transfer through the cocoon wall effectively. This has practical significance for the development of thermal functional textiles and composite structures.

A Liquid Crystal-Based Passive Badge for Personal Monitoring of Exposure to Hydrogen Sulfide

A new liquid crystal (LC)-based passive dosimeter badge for personal monitoring of exposure to hydrogen sulfide (H2S) gas is reported. When a thin film of LC supported on a surface functionalized with lead perchlorate Pb(ClO4)2 (the LC sensor) is exposed to H2S, the orientation of LC molecules in the film changes from perpendicular to parallel. This reorientation induces a change in the appearance of the LC film when viewed between crossed polarizers. A H2S dosimeter was fabricated by pairing a LC sensor with a glass substrate forming a headspace between the two surfaces, to control diffusion of H2S across the LC film. When the dosimeter is exposed to H2S, a bright front appears as a function of exposure time. An algorithm has been developed to correlate this response length and exposure dose. The dosimeters are functionally stable when subjected to extreme temperature and humidity fluctuations, and are immune to a number of potentially interfering chemicals, except mercaptans. These dosimeters detect H2S at 0.2 ppm TWA (8 hr) with ±20% overall accuracy. The dosimeters were used to monitor the personal exposure of personnel working in an oil refinery. The TWA concentrations measured by the LC-based dosimeters correlate strongly with the NIOSH 1063 method that uses a sorbent tube and a pump followed by laboratory analysis. Thus, the LC-based dosimeters can provide a sensitive tool for on-site assessment of personal exposure to H2S in different environments.

Ecosystem governance in a highland village in Peru: Facing the challenges of globalization and climate change

The agricultural systems of the Peruvian Andes have been created and maintained over many generations using locally adapted management practices that help to maintain agrobiodiversity while providing for local populations. Despite their longstanding history, many of these ecosystems and the services they provide are currently threatened by a number of economic and environmental factors. We use findings from behavioral science to examine the opportunities and conflicts at different governance levels—individual, community, and global. Market pressures to produce for distant markets have resulted in reduced diversity of crops in the Andes region. Another major threat to ecosystem services in the region is climate change, which is already being observed in the form of rising temperatures, extreme temperature fluctuation, changing rainfall patterns, and increasing glacial melt. To explore the effects of, and the responses to, these pressures we used semi-structured interviews to gain insight into agricultural practices and challenges and the various levels of governance present in the agriculture of Langui, Peru. We find that low staple crop prices combined with increasing climate variability has led to a reduced production of traditional crops such as pseudocereals and tubers in favor of production of improved grasses for livestock. The growth of the livestock economy is being driven by the presence of a transnational dairy corporation in the region, plus increased migration leading to a reduced local labor force. We conclude that loss of traditional crops and community based agricultural management techniques will make it difficult for smallholders to maintain food self-sufficiency and agrobiodiversity in the face of a changing climate and global economy.