Environmental Dynamics in Animal Waste Reclamation in the Scaling up of Livestock in Thailand

Thailand has seen a scaling up of pig production in numbers and structure. Nonetheless, in-house separation and agricultural reclamation of pig solid waste are common practice. Waste reclamation is not taking place under small-scale farming and its environmental dynamics cannot be simply understood as a direct projection to larger scales. Scaling up has transformed the environmental significance of waste reclamation, including waste transfer from livestock to agriculture farmers. Waste transfer benefits pig farmers by trade and removal of waste by agriculture and aquaculture farmers and is key to the environmental dynamics of pig production. However, waste reclamation is not clearly defined as a management option in environmental frameworks. Waste management is mainly addressed as in-farm wastewater with limited attention to agro-environmental values of present practices. To recognise present practices in agro-environmental policies this thesis suggests a descriptive strategy focused on the transfer of waste. Such strategy would avoid command-and-control norms, avoid conflicting with an environmental culture centered in biogas technology and support knowledge transfer in agriculture. A focus on waste transfer from animal farms to agriculture [and aquaculture] plots is interpreted as off-site waste management. Off-site waste management calls for the inclusion of geographical variables beyond animal farms. This leads to an extended area of environmental influence (EAEI). Resulting environmental dynamics allows an interpretation of environment beyond resource in classical agricultural geography to a connotation where environment is also significant to agriculture and livestock because of the impacts from production. The recognition of reclamation practices and, consequently, of the integral environmental dynamics, and hence the connotation of environment, would contribute to connect livestock with agriculture through environmental geography. Intensive livestock is then defined as distribution and not location. Formalisation of reclamation practices entails the acknowledgment of agro-ecological cycles in livestock

Selection for Gaia across multiple scales

This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record.Recently postulated mechanisms and models can help explain the enduring ‘Gaia’ puzzle of environmental regulation mediated by life. Natural selection can produce nutrient recycling at local scales and regulation of heterogeneous environmental variables at ecosystem scales. However, global-scale environmental regulation involves a temporal and spatial decoupling of effects from actors that makes conventional evolutionary explanations problematic. Instead, global regulation can emerge by a process of ‘sequential selection’ in which systems that destabilize their environment are short-lived and result in extinctions and reorganizations until a stable attractor is found. Such persistence-enhancing properties can in turn increase the likelihood of acquiring further persistence-enhancing properties through ‘selection by survival alone’. Thus, Earth system feedbacks provide a filter for persistent combinations of macroevolutionary innovations.T.M.L. was supported by a Royal Society Wolfson Research Merit Award. A.E.N. was supported by Gaia Charity and the University of Exeter

Improving productivity in tropical lakes and reservoirs

Freshwater aquaculture, Inland fisheries

The maintenance of habitability across multiple scales: A meta ecosystem view of Gaia

The Gaia hypothesis postulates that life and the abiotic environment of planet Earth form a self-regulating system, capable of maintaining planetary habitability. Previous studies have highlighted mechanisms by which environmental regulation can emerge. The majority of prior work has modelled life-environment interactions at the level of organisms interacting with their local environment. The model presented in this thesis uses a meta ecosystems approach to look at not just how organisms interact with their environment but how ecosystems interact with each other and a shared global environment. It is hypothesised that interaction through a shared environment decreases the probability of ecosystem collapse within a world consisting of numerous ecosystems. To test this hypothesis a version of the flask model is used where numerous ecosystem flasks exist within a global flask and interact with a shared environment. It is found that when ecosystems are able to interact with, and through, a shared global environment the probability of ecosystem collapse is reduced. It is postulated that this is caused through a novel form of meta-ecosystem dynamics where, through interaction with a shared environment, ecosystems are able to affect one another's population and therefore likelihood of extinction. This appears to be another way, apart from regulation of abiotic factors and nutrient recycling, in which life environment feedbacks can affect the habitability of a global system

Ecological autocatalysis:A central principle in ecosystem organization?

Ecosystems comprise flows of energy and materials, structured by organisms and their interactions. Important generalizations have emerged in recent decades about conversions by organisms of energy (metabolic theory of ecology) and materials (ecological stoichiometry). However, these new insights leave a key question about ecosystems inadequately addressed: are there basic organizational principles that explain how the interaction structure among species in ecosystems arises? Here we integrate recent contributions to the understanding of how ecosystem organization emerges through ecological autocatalysis (EA), in which species mutually benefit through self-reinforcing circular interaction structures. We seek to generalize the concept of EA by integrating principles from community and ecosystem ecology. We discuss evidence suggesting that ecological autocatalysis is facilitated by resource competition and natural selection, both central principles in community ecology. Furthermore, we suggest that pre-emptive resource competition by consumers and plant resource diversity drive the emergence of autocatalytic loops at the ecosystem level. Subsequently, we describe how interactions between such autocatalytic loops can explain pattern and processes observed at the ecosystem scale, and summarize efforts to model different aspect of the phenomenon. We conclude that EA is a central principle that forms the backbone of the organization in systems ecology, analogous to autocatalytic loops in systems chemistry.</p

Soil biodiversity: functions, threats and tools for policy makers

Human societies rely on the vast diversity of benefits provided by nature, such as food, fibres, construction materials, clean water, clean air and climate regulation. All the elements required for these ecosystem services depend on soil, and soil biodiversity is the driving force behind their regulation. With 2010 being the international year of biodiversity and with the growing attention in Europe on the importance of soils to remain healthy and capable of supporting human activities sustainably, now is the perfect time to raise awareness on preserving soil biodiversity. The objective of this report is to review the state of knowledge of soil biodiversity, its functions, its contribution to ecosystem services and its relevance for the sustainability of human society. In line with the definition of biodiversity given in the 1992 Rio de Janeiro Convention, soil biodiversity can be defined as the variation in soil life, from genes to communities, and the variation in soil habitats, from micro-aggregates to entire landscapes. Bio Intelligence Service, IRD, and NIOO, Report for European Commission (DG Environment

Rotating biological contactors for wastewater treatment - A review

Rotating biological contactors (RBCs) for wastewater treatment began in the 1970s. Removal of organic matter has been targeted within organic loading rates of up to 120 g m−2 d−1 with an optimum at around 15 g m−2 d−1 for combined BOD and ammonia removal. Full nitrification is achievable under appropriate process conditions with oxidation rates of up to 6 g m−2 d−1 reported for municipal wastewater. The RBC process has been adapted for denitrification with reported removal rates of up to 14 g m−2 d−1 with nitrogen rich wastewaters. Different media types can be used to improve organic/nitrogen loading rates through selecting for different bacterial groups. The RBC has been applied with only limited success for enhanced biological phosphorus removal and attained up to 70% total phosphorus removal. Compared to other biofilm processes, RBCs had 35% lower energy costs than trickling filters but higher demand than wetland systems. However, the land footprint for the same treatment is lower than these alternatives. The RBC process has been used for removal of priority pollutants such as pharmaceuticals and personal care products. The RBC system has been shown to eliminate 99% of faecal coliforms and the majority of other wastewater pathogens. Novel RBC reactors include systems for energy generation such as algae, methane production and microbial fuel cells for direct current generation. Issues such as scale up remain challenging for the future application of RBC technology and topics such as phosphorus removal and denitrification still require further research. High volumetric removal rate, solids retention, low footprint, hydraulic residence times are characteristics of RBCs. The RBC is therefore an ideal candidate for hybrid processes for upgrading works maximising efficiency of existing infrastructure and minimising energy consumption for nutrient removal. This review will provide a link between disciplines and discuss recent developments in RBC research and comparison of recent process designs are provided (Section 2). The microbial features of the RBC biofilm are highlighted (Section 3) and topics such as biological nitrogen removal and priority pollutant remediation are discussed (Sections 4 and 5). Developments in kinetics and modelling are highlighted (Section 6) and future research themes are mentioned

Holistic biomimicry: a biologically inspired approach to environmentally benign engineering

Humanity's activities increasingly threaten Earth's richness of life, of which mankind is a part. As part of the response, the environmentally conscious attempt to engineer products, processes and systems that interact harmoniously with the living world. Current environmental design guidance draws upon a wealth of experiences with the products of engineering that damaged humanity's environment. Efforts to create such guidelines inductively attempt to tease right action from examination of past mistakes. Unfortunately, avoidance of past errors cannot guarantee environmentally sustainable designs in the future. One needs to examine and understand an example of an environmentally sustainable, complex, multi-scale system to engineer designs with similar characteristics. This dissertation benchmarks and evaluates the efficacy of guidance from one such environmentally sustainable system resting at humanity's doorstep - the biosphere. Taking a holistic view of biomimicry, emulation of and inspiration by life, this work extracts overarching principles of life from academic life science literature using a sociological technique known as constant comparative method. It translates these principles into bio-inspired sustainable engineering guidelines. During this process, it identifies physically rooted measures and metrics that link guidelines to engineering applications. Qualitative validation for principles and guidelines takes the form of review by biology experts and comparison with existing environmentally benign design and manufacturing guidelines. Three select bio-inspired guidelines at three different organizational scales of engineering interest are quantitatively validated. Physical experiments with self-cleaning surfaces quantify the potential environmental benefits generated by applying the first, sub-product scale guideline. An interpretation of a metabolically rooted guideline applied at the product / organism organizational scale is shown to correlate with existing environmental metrics and predict a sustainability threshold. Finally, design of a carpet recycling network illustrates the quantitative environmental benefits one reaps by applying the third, multi-facility scale bio-inspired sustainability guideline. Taken as a whole, this work contributes (1) a set of biologically inspired sustainability principles for engineering, (2) a translation of these principles into measures applicable to design, (3) examples demonstrating a new, holistic form of biomimicry and (4) a deductive, novel approach to environmentally benign engineering. Life, the collection of processes that tamed and maintained themselves on planet Earth's once hostile surface, long ago confronted and solved the fundamental problems facing all organisms. Through this work, it is hoped that humanity has taken one small step toward self-mastery, thus drawing closer to a solution to the latest problem facing all organisms.Ph.D.Committee Chair: Bert Bras; Committee Member: David Rosen; Committee Member: Dayna Baumeister; Committee Member: Janet Allen; Committee Member: Jeannette Yen; Committee Member: Matthew Realf

Plankton vertical migrations - Implications for the pelagic ecosystem

Habitat selection is an important behavior of many organisms. The direction and strength of this behavior is often characterized as a result of a trade off between predator avoidance and obtaining resources. A characteristic example of this trade off may be seen in organisms in the pelagic ecosystem in the form of vertical migrations. Diel vertical migration (DVM) is a predator avoidance behavior of many zooplankton species, which is marked by a significant shift in the vertical distribution of the zooplankton where night time is spent in the epilimnion and day time in the hypolimnion While the causes of DVM and its ecophysiological consequences for the zooplankton are well studied, little is known about the consequences of DVM for the pelagic food ecosystem. Vertical migrations are not only restricted to zooplankton but are often exhibited by phytoplankton species, which respond to vertical gradients of light and nutrient availability. Many phytoplankton species cope with light and nutrient gradients by changing their position in the water column through active movement or buoyancy adjustment. The costs and consequences of this phytoplankton behavior are hardly studied. In my thesis, I studied the consequences of zooplankton DVM for the pelagic food web and the consequences of phytoplankton vertical migrations on individual growth and biomass composition through both field and laboratory experiments. I, Upward phosphorus transport by Daphnia DVM: During stagnation periods of the water column, physical upward transport processes are very unlikely and nutrients become scarce in the photic zone of many lakes. DVM of zooplankton could be a mechanism of nutrient repletion in the epilimnion. I experimentally examined the upward transport of phosphorus by Daphnia DVM. Results revealed that Daphnia DVM caused an upward nutrient transport. The amount of phosphorus transported and released by Daphnia in my study was within a biologically meaningful range: five percent of the estimated daily maximum phosphorus uptake of the phytoplankton community in the epilimnion. Therefore, nutrient transport by Daphnia DVM could be a significant mechanism in fuelling primary production in the phosphorus limited epilimnion. II, Daphnia DVM: implications beyond zooplankton: DVM creates a temporal and spatial predator-free niche for the phytoplankton, and theoretical models predict that parts of the phytoplankton community could use this niche. I experimentally investigated the influence of Daphnia DVM on the phytoplankton community of an oligotrophic lake in field mesocosms. My results suggest that Daphnia DVM had significant effects on quantitative and qualitative characteristics of the phytoplankton community. Phytoplankton biomass was higher in “no DVM” treatments. DVM also increased diversity in the phytoplankton community. The analyses showed that the gelatinous green algae Planktosphaeria gelatinosa was the main species influencing phytoplankton dynamics in the experiment, and therefore the effects of Daphnia DVM were highly species specific. III, Initial size structure of natural phytoplankton communities determines the response to Daphnia DVM: Previous studies have shown that the direction and strength of phytoplankton responses to zooplankton DVM most likely depends on the size of the phytoplankton species. To examine the influence of DVM on different sized phytoplankton communities, I manipulated the size distribution of a natural phytoplankton community a priori in field mesocosms. The results reveal that DVM oppositely affected the two different phytoplankton communities. A comparison of “DVM” and “no DVM” treatments showed that nutrient availability and total phytoplankton biovolume was higher in “no DVM” treatments of phytoplankton communities consisting mainly of small algae, whereas it was higher in “DVM” treatments of phytoplankton communities with a wide size spectrum of algae. It seemed that two different mechanisms on how DVM can influence the phytoplankton community were at work. In communities of mainly small algae nutrient recycling was important, seemed to be important, whereas in communities with a wide size spectrum of algae the refuge effect played the dominant role. IV, Carbon sequestration and stoichiometry of motile and non-motile green algae: The ability to move actively should entail costs in terms of increased energy expenditure and the provision of specific cell structures for movement. In a laboratory experiment, I studied whether motile, flagellated and non-motile phytoplankton taxa differ with respect to their energetic costs, phosphorus requirements, and structural carbon requirements. The results show that flagellated taxa had higher respiration rates and higher light requirements for growth than non-motile taxa. Accordingly, both short-term photosynthetic rates and long-term biomass accrual were lower for flagellated than for non-motile taxa. My results point at significant costs of motility, which may explain why flagellated taxa are often outcompeted by non-motile taxa in turbulently mixed environments, where active motility is of little use. The data in this study also suggest that motility alone may not be sufficient to explain the lower C: P ratios of flagellates. In summary, my results show that migrating phytoplankton and zooplankton species can act as a vector transporting energy, organic matter and ecological interaction. The complex consequences for the pelagic ecosystem are thereby determined by the organisms´ activity and characterized by their life history

Spatial variability in benthic macrofauna communities and associated ecosystem functions across coastal habitats

The rapid rates of global biodiversity loss and the serious anthropogenic pressures currently affecting our marine ecosystems have increased the interest in and importance of understanding the role of biodiversity for ecosystem functioning. It is well known that biodiversity contributes to a plethora of ecosystem functions, and that benthic macrofauna have an influence on several functions that sedimentary ecosystems provide. Biodiversity-ecosystem function relationships can however be very context dependent, which complicates our ability to generalize on the role of biodiversity and to predict the consequences of environmental change for ecosystem functions and services. In this thesis, biodiversity-ecosystem functioning (BEF) relationships were examined in a variety of field studies in different ecosystems to elucidate the context-dependence of these relationships in heterogeneous real-world coastal zones. This included testing the effects of hypoxia, habitat characteristics and background biodiversity on the link between the fauna and the functioning in terms of benthic nutrient recycling. Hypoxia is a serious threat both in open and coastal waters, and its consequences for the benthic macrofauna-function link was investigated through sampling along natural gradients of increasing hypoxia, in a low-diversity as well as a higher-diversity coastal system. In both systems, the benthic macrofaunal communities were clearly decimated with declining oxygen conditions, although some species did show a higher tolerance of low oxygen concentrations. These species were likely important for the solute fluxes as long as the species could prevail, but during severe hypoxia and anoxia nutrient recycling processes were heavily altered, with markedly larger effluxes of ammonium and phosphate. A large variation in macrofaunal communities and solute fluxes was also observed between normoxic sites, with indications that even small variations in sediment organic material content and carbon/nitrogen ratio affected the relationships. The effects of environmental context in mediating ecosystem functioning were further assessed through sampling 18 sites on a gradient of grain size, from coarse sand to silty sediments, with varying organic material content and vegetation. Benthic macrofaunal community abundance, biomass and species richness was higher in coarser sediments and in habitats with more vegetation. Biomass and abundance of a few dominant species together with organic content, amount of roots and vegetation were indicated to contribute to nutrient recycling processes across the sedimentary gradient. Closer analyses suggested that the benthic macrofauna had a stronger influence on the ecosystem functions in muddy and medium sediments than in sandy sediment, despite the richer communities in the sandy sediments. Species redundancy is hypothesised to be important for the stability of ecosystems. Therefore redundancy patterns over space and their ability to reflect natural biodiversity-ecosystem function relationships across an extensive sandflat were explored. Redundancy over space was observed within the investigated functional groups, but the dominant species were indicated to drive the spatial distribution of the functional groups and the ecosystem functioning. In summary, these correlative field studies indicated that abundance and biomass of benthic macrofauna are important for nutrient recycling processes at the sediment-water interface, but the relationships are significantly mediated by environmental context. Hypoxic conditions in coastal zones are especially problematic because the heavily altered nutrient recycling processes and decimated macrofauna communities, can have severe consequences for overall functioning of the ecosystems. Furthermore, a few dominating species were suggested to be especially important for the investigated ecosystem functions regardless of large variations in species richness across studies. Hence, it is important to consider natural variability, as well as several measures of biodiversity, not only species richness, in BEF studies in order to obtain a more realistic understanding of the biodiversity-ecosystem function relationships in heterogeneous coastal areas. An improved understanding of the complex links within coastal ecosystems is a prerequisite for improved management and conservation.Den hotande globala minskningen av biodiversitet har ökat vikten av att förstå hur biodiversitet är kopplad till ekosystemens funktion. Vi saknar dock en heltäckande förståelse av hur biodiversitet bidrar till ekosystemens funktioner under naturliga förhållanden. Det finns många teorier som baserar sig på laboratoriestudier, men få har visat på hur stor variationen är under de mångfacetterade förhållandena i den verkliga naturen. Det övergripande målet med studierna i denna avhandling var att undersöka vilken roll bottenfaunan spelar för ekosystemens funktioner, specifikt för näringsomloppets processer i havsbottnen i den komplexa och heterogena kustzonen. Bottenfaunan är en mycket viktig komponent för att många processer i ekosystemen ska fungera, t.ex. för återcirkulation och lagring av näringsämnen i havsbottnen. Övergödning längs kusterna har dock en negativ påverkan på både bottenfaunasamhällena och på de viktiga biogeokemiska processerna som styr ekosystemens näringsomlopp, bl.a. genom att övergödningen ökar produktionen av organiskt material och kan därmed potentiellt orsaka syrebrist. För att kvantifiera variationen i bottenfaunans roll för näringsomloppet i olika kustmiljöer, undersöktes faunasamhällen och näringsprocesser i områden med syrebrist, och i varierande grunda havsmiljöer med olika sorters sediment och växtlighet. Studierna kunde visa att bottenfaunan är mycket viktig för näringsomloppets processer men att deras roll starkt påverkas av de omgivande förhållandena. Under syrefattiga förhållanden decimerades bottenfaunasamhällena kraftigt och näringsprocesserna ändrades, speciellt återcirkuleringen av fosfor och kväve ökade markant under dåliga syreförhållanden. Bottenfaunan påverkade näringsprocesserna i högre grad i leriga sediment jämfört med i sandiga sediment, även om högre abundanser och biomassor av bottenfauna observerades i de sandigare sedimenten. Dessa studier indikerade vidare att ett fåtal dominerande arter var speciellt viktiga för de ekosystemfunktioner som undersöktes. Sammanfattningsvis kunde resultaten visa att det är mycket viktigt att varierande omgivningsförhållanden, samt många mått på biodiversitet (så som abundans, biomassa och artidentitet) tas i beaktande i studier kring kopplingen mellan biodiversitet och ekosystemens funktioner. En ökad förståelse av biodiversitetens roll för ekosystemens funktioner krävs för att möjliggöra en ändamålsenlig förvaltning av våra kustekosystem