Historical and emerging practices in ecological topology

“Ecological topology” has recently been highlighted as a “frontier of ecology,” yet the term “ecological topology” only occasionally appears in the literature. On the other hand, the term “topology” appears in a variety of publications in this and other ecologically oriented journals, but its use is varied and applied to a wide cross-section of ecological problems. These variable usages suggest that topology does not have a common meaning to all ecologists. Part of this confusion results from the fact that topological ways of seeing nature are both formally derived from mathematical origins, and informally derived from non-mathematical conceptualizations. Interestingly, parallels occur between both mathematically originated and conceptually originated topology with respect to object-oriented, network topologies (formally derived from Eulerian mathematics), and field-oriented, manifold topologies (formally derived from Poincaréian mathematics). Topological ways of understanding nature and addressing both theoretical and applied problems have served ecology well in the past, but this approach will be improved with a better, more unified understanding among ecologists as to the variety of meanings found and practiced in the science.     

Use and non-use values as motivational construct dimensions for farm animal welfare: impacts on the economic outcome for the farm

This study explored how farmers’ motivation in terms of use values and/or non-use values to work with farm animal welfare are associated with the economic outcome for the farm. Use values in farm animal welfare refer to economic value derived from productivity and profitability considerations. Non-use values in farm animal welfare refer to economic value derived from good animal welfare, irrespective of the use the farmer derives from the animal, currently or in the future. The analysis was based on detailed information about the income statements of a sample of Swedish dairy farmers, obtained from the Swedish Farm Economic Survey, complemented with survey information about their perceived use and non-use values in farm animal welfare. The findings suggest that farm economic outcome is significantly associated with motivation in terms of use values, but not so much with motivation in terms of non-use values. This is interesting from a policy point of view, because it indicates that farmers with different approaches to farm animal welfare may experience different economic outcomes for their farms. Findings can, for instance, be used to strengthen farmers’ engagement in various private quality assurance standards, which generally focus on values of non-use type, by pointing to that realisation of such values will not impair the economic outcome of the farms. Moreover, findings also suggest that farmers’ economic incentives for engagement in such standards may need to be further strengthened in order to become more attractive, as findings point to that a focus on non-use values generally is not associated with more favourable economic outcomes.     

Preliminary Observations on the Nature,Taxonomic Composition,Distribution, Behaviour and Nutrient Requirements of the “Unusual” Algal “Jellies” of Oguta Lake in Southeastern Nigeria

Preliminary observations were made between October 1982 and May 1983 on the nature, taxonomic composition, spatial distribution, buoyancy behaviour and nutrient requirements of some unusual planktonic algal “jellies” in Oguta Lake in Southeastern Nigeria. These “jellies” are macroscopic, blue-green algal masses whose excessive mucilage of high consistency acts as substrata for other epiphytic components viz. diatoms and green algae. They are more abundant in the lentic areas of the lake, undergo diurnal vertical movements and have their growth enhanced by spikes of nitrogen and phosphorus salts into their aquatic medium. The effects of these “jellies” on the ecology and general water use of the lake are discussed. Speculations on the reasons for their occurrence are given and possible control measures outlined.     

How ecologists define drought,and why we should do better

Drought, widely studied as an important driver of ecosystem dynamics, is predicted to increase in frequency and severity globally. To study drought, ecologists must define or at least operationalize what constitutes a drought. How this is accomplished in practice is unclear, particularly given that climatologists have long struggled to agree on definitions of drought, beyond general variants of “an abnormal deficiency of water.” We conducted a literature review of ecological drought studies (564 papers) to assess how ecologists describe and study drought. We found that ecologists characterize drought in a wide variety of ways (reduced precipitation, low soil moisture, reduced streamflow, etc.), but relatively few publications (~32%) explicitly define what are, and are not, drought conditions. More troubling, a surprising number of papers (~30%) simply equated “dry conditions” with “drought” and provided little characterization of the drought conditions studied. For a subset of these, we calculated Standardized Precipitation Evapotranspiration Index values for the reported drought periods. We found that while almost 90% of the studies were conducted under conditions quantifiable as slightly to extremely drier than average, ~50% were within the range of normal climatic variability. We conclude that the current state of the ecological drought literature hinders synthesis and our ability to draw broad ecological inferences because drought is often declared but is not explicitly defined or well characterized. We suggest that future drought publications provide at least one of the following: (a) the climatic context of the drought period based on long‐term records; (b) standardized climatic index values; (c) published metrics from drought‐monitoring organizations; (d) a quantitative definition of what the authors consider to be drought conditions for their system. With more detailed and consistent quantification of drought conditions, comparisons among studies can be more rigorous, increasing our understanding of the ecological effects of drought.     

Insights into discriminating water quality status using new biodiversity measures based on a trait hierarchy of body-size units

Biofilm-dwelling protozoa have successfully used as a feasible bioindicator for bioassessment of water quality status in marine ecosystems. Based on a dataset of biofilm-dwelling protozoa in coastal waters of the Yellow Sea, we demonstrated a spatial variation in body-size spectrum of protozoan communities along a gradient of increasing environmental pollution. Two biodiversity indices, as a new indicator of water quality, were proposed, first being body-size diversity (Δ′) logistically corresponded to taxonomic diversity index but with a trait hierarchy of body-size units based on Euclidean distance resemblance, and the second a modified body-size diversity index (Δ′_m) with a modified hierarchy based on the trait matrix. The values of both indices Δ′ and Δ′_m were found to be significantly correlated with the changes of environmental variables, especially the nutrients. Furthermore, the body-size diversity (Δ′_mrk) at body-size-rank-1 (“genus-level”) resolution might be used as a potential surrogate of those at “species-level” resolution. Thus, we suggest that the ecological parameters based on body-size spectrum may be used as potential bioindicator of water quality status, and that the body-size rank sufficiency might be an effective time-efficient protocol for monitoring programs by identifying taxa to “genus-level” body-size rank.     

Assessing water quality of five typical reservoirs in lower reaches of Yellow River,China: Using a water quality index method

To assess water quality of reservoirs in lower reaches of Yellow River using the water quality index (WQI) method and try to compare water quality and main contaminations of mountain and Yellow River reservoirs, water samples were carried out over 6 years. Nine water variables were selected to participate WQI calculation by Principal Component Analysis (PCA). WQI values ranged from 17.8 to 77.8 in five reservoirs, which indicated “good” to “very poor” water quality of reservoirs. No significant differences in WQIs were found between mountain and Yellow River reservoirs. A major finding from our study is that mercury was the main contamination in 5 reservoirs, while TP (total phosphorus) and SO₄ were another main contaminations in mountain and Yellow River reservoirs, respectively. Application of the WQI is suggested to be a helpful tool that enables the public and decision makers to evaluate water quality of drinking reservoirs in lower reaches of Yellow River.     

Soil‐dwelling insect pests of tree crops in Sub‐Saharan Africa,problems and management strategies—A review

This review aims to draw the attention of researchers, ecologists and farmers to the threats of soil‐dwelling insect pests on important tree crops in sub‐Saharan Africa, with a special focus on termites. It synthesizes the information on the effects of various factors affecting soil pest occurrence and damage, suggesting that the resultant undesirable effects of soil pests in this region are largely as a result of indiscriminate tree cutting, slash‐and‐burn agriculture and indiscriminate use of pesticides. Major insect orders, their host ranges and the nature of damage on selected tree crops are described. This study further critiques existing soil pest management practices, showing that majority of soil pest management practices are ineffective. Thus, management strategies like “attract and kill” approach based on entomopathogenic fungi need to be studied, developed and emphasized for the management of soil insect pests in sub‐Saharan Africa. A conclusion section attempts to offer suggestions for ways in which future work on soil pests in sub‐Saharan Africa could proceed.     

WEIGHTING HEALTH STATES AND STRONG EVALUATION*

The problem of public consultation over the allocation of health care resources is addressed by considering the role that quality of life measures, such as QALYs and the Nottingham Health Profile, could play. Such measures are typically grounded in social surveys, and as such may reflect public preferences for health care priorities. Using Charles Taylor's concepts of “weak” and “strong” evaluation, it is suggested that current quality of life measures are inadequate, insofar as they typically presuppose that survey respondents are mere “weak evaluators”, who express only inarticulate preferences. Respondents may, conversely, be understood as strong evaluators, with deeper visions of human nature and the good life informing their health preferences. Space is then created for such respondents to be asked to defend their preferences, and so be encouraged to reflect critically and publicly on the beliefs and prejudices that ground their view of health care priorities.     

Perceptions and Measurements: The Assessment of Pasture States in a Semi-Arid Area of Namibia

How farmers perceive the state of their pastures is an important component of their management decisions and affects natural resources in arid and semi-arid regions. In an explorative study conducted in the Rehoboth farm area of central Namibia, we addressed the question whether the judgments of commercial farmers on pasture conditions are consistent with a botanical assessment of these pastures based on measurements. The perceptions were inferred from the comparative statements of farmers on the pasture quality of adjacent farm pairs. For the botanical assessment, biomass and plant species frequency counts of the same pastures were used. The results of the statistical analysis show a large agreement between perceived and measured pasture states of corresponding farm pairs, thus pasture quality dimensions perceived by the farmers agreed with the measured pasture quality variables. We also discuss the problems of designing more elaborate studies of this type.     

Use of the water quality index and dissolved oxygen deficit as simple indicators of watersheds pollution

The use of the water quality index (WQI) and the dissolved oxygen deficit (D) as simple indicators of the watersheds pollution was investigated and compared in the Municipality of Las Rozas (north-west of Madrid, Spain). The quality of the water in Guadarrama and Manzanares rivers and Paris Park ponds, the main watersheds of this area was investigated during 2 years (from September 2001 to September 2003). It was found that the WQI was very useful for the classification of the waters monitored. The WQI was 70, which corresponds to “good” quality water at the sampling point 1 (entrance of Las Rozas) and decreased to around 64 (medium quality) at the sampling point 6 (outlet of Las Rozas) in the case of Guadarrama River. The WQI was around 65 in the influents of Manzanares River. Finally, in Paris Park the WQI ranged from around 72–55, which corresponded to a classification from “good” to “medium” quality, respectively. A high linear relationship between the WQI and the dissolved oxygen deficit (D) was found. Therefore, a fast determination of WQI may be carried out knowing the values of D, which are easily obtainable by field measurements. It was found an influence of the climate conditions on the values of WQI and D.     

Ecological Stability: Reality,Misconceptions, and Implications for Risk Assessment

Over a long time frame, an ecological system may not exhibit constancy due to successional and evolutionary changes in the species composing the system. However, over shorter time frames an ecological system exhibits a certain degree of constancy (i.e., varies within defined bounds). Traditionally, ecologists considered this short-term constancy to reflect a “balance of nature,” which was viewed akin to the simple homeostatic dynamics of physiological systems. This is an appealing perspective because the disruption of the system's “balance” (i.e., its ”health“) can be ascertained by comparing the system's current state after the imposition of a perturbation with the societally desired state (i.e., baseline). Recently, ecologists have started to develop a much more complex, and perhaps more realistic, perspective regarding ecosystem dynamics, which does not depend upon homeostasis with a single baseline state. This new view includes stochastic variation, nonlinear dynamics and alternative states, and poses a challenge for assessing environmental “health” and the risk of creating “unhealthy” ecological systems     

Aggregation of measures to produce an overall assessment of animal welfare. Part 1: a review of existing methods

Several systems have been proposed for the overall assessment of animal welfare at the farm level for the purpose of advising farmers or assisting public decision-making. They are generally based on several measures compounded into a single evaluation, using different rules to assemble the information. Here we discuss the different methods used to aggregate welfare measures and their applicability to certification schemes involving welfare. Data obtained on a farm can be (i) analysed by an expert who draws an overall conclusion; (ii) compared with minimal requirements set for each measure; (iii) converted into ranks, which are then summed; or (iv) converted into values or scores compounded in a weighted sum (e.g. TGI35L) or using ad hoc rules. Existing methods used at present (at least when used exclusively) may be insufficiently sensitive or not routinely applicable, or may not reflect the multidimensional nature of welfare and the relative importance of various welfare measures. It is concluded that different methods may be used at different stages of the construction of an overall assessment of animal welfare, depending on the constraints imposed on the aggregation process.     

Organic farm does not improve neither soil,or water quality in rural watersheds from southeastern Brazil

This study was conducted in a rural region where there are conventional and organic farms, the agricultural production includes more than 20 million people, and the effect on environmental quality is still poorly known in terms of indicators. Our objectives were: (1) compare soils attributes to reference areas, (2) verifying if cultivated areas under different farm systems presented differences in the soils attributes, (3) evaluate the attributes of quality water of watersheds and comparing the results with limiting values established by environmental legislation, and (4) analyze the values considering three criterion: watersheds, climatic season, and region of the landscapes. The study was conducted in two rural watersheds that have similar biophysical features and located in the Ibiúna municipality, São Paulo State, Brazil. However, one watershed encompasses farms where landowners largely use conventional agricultural systems. In the other watershed approximately 25% of the farms there are using an organic farm system. In the two watersheds soil samples were collected in sites covered with natural forest and in sites with agriculture (one watershed being organic and other being conventional). The attributes analyzed were soil bulk density (BD), concentrations of Carbon (C) and Nitrogen (N), C:N ratio, C Management Index, and the abundance of ¹³C and ¹⁵N in the soil organic matter. Water attributes were analyzed onsite or in laboratory after analysis of samples. Analyses included: air and water temperature, pH, dissolved oxygen, salinity, total of dissolved solids, total solids, electric conductivity, turbidity, total chloride, nitrate, total phosphorus and potassium. Regarding the soil attributes our database revealed that (1) the soils from cultivated sites of both watersheds presented significant differences from their respective forested areas, (2) Soil attributes are of equal quality in both farm systems. Concerning water attributes: (1) almost all attributes presented values better than the limiting values stipulated by Brazilian legislation; (2) the watersheds did not present significant differences of most of the attributes; (3) in the criteria climatic season data showed some significant differences. The data showed that the soils from the areas used for agricultural ends present belief that significantly worse soil quality in comparison to soils from sites still covered with natural forest. Neither the land cover nor farming system are altering the superficial water quality of the studied watershed and this appears to be related to the extensive percentage of natural remaining vegetation that still exists in both watersheds. The seasonality is an important force that drives the quality characteristics of the water. We highlight that the principles of organic agriculture should be practiced more efficiently and influences such as deforestation should be rigorously avoided.     

Assessing water scarcity by simultaneously considering environmental flow requirements,water quantity,and water quality

Water scarcity is a widespread problem in many parts of the world. Most previous methods of water scarcity assessment only considered water quantity, and ignored water quality. In addition, the environmental flow requirement (EFR) was commonly not explicitly considered in the assessment. In this study, we developed an approach to assess water scarcity by considering both water quantity and quality, while at the same time explicitly considering EFR. We applied this quantity–quality-EFR (QQE) approach for the Huangqihai River Basin in Inner Mongolia, China. We found that to keep the river ecosystem health at a “good” level (i.e., suitable for swimming, fishing, and aquaculture), 26% of the total blue water resources should be allocated to meet the EFR. When such a “good” level is maintained, the quantity- and quality-based water scarcity indicators were 1.3 and 14.2, respectively; both were above the threshold of 1.0. The QQE water scarcity indicator thus can be expressed as 1.3(26%)|14.2, indicating that the basin was suffering from scarcity problems related to both water quantity and water quality for a given rate of EFR. The current water consumption has resulted in degradation of the basin's river ecosystems, and the EFR cannot be met in 3 months of a year. To reverse this situation, future policies should aim to reduce water use and pollution discharge, meet the EFR for maintaining healthy river ecosystems, and substantially improve pollution treatment.     

A Data Reduction Exercise to Detect Threshold Samples for Regression Models to Predict Key Water Variables

Inherent uncertainties in empirical data limit our understanding of interrelationships among variables and constrain our possibilities to identify critical thresholds as well as our possibilities to develop practically useful predictive models for water management. This work concerns key water variables for water management and the first aim is to utilize a very comprehensive set of data set for Ringkobing Fjord, Denmark. The paper first presents the methods and data used, then a reference regression for chlorophyll, coefficients of variation (CV = SD/MV; MV = mean value; SD = standard deviation) for a variety of water variables and how these CV‐values influence n, the number of data used to determine coastal area characteristic mean or median values (note that the interest here is not on the conditions in sampling bottle but on the conditions in entire coastal areas, the ecosystem perspective). The main part of the work presents a data reduction exercise including a definition of an error function where the focus is on “large N”, i.e., the number of data in a regression. The results are summarized in a diagram relating the error in the regression to different water variables with different inherent CVs in rivers, lakes and coastal areas. Given the inherently high CV‐values of many of these water variables, more samples than generally taken in most regular monitoring programs are needed if scientific unassailable conclusions are to be made concerning interrelationships among the variables and to produce scientifically meaningful information to detect critical ecosystem changes and threshold values. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Threshold values of canopy reflectance indices and chlorophyll meter readings for optimal nitrogen nutrition of tomato

Sustainable and optimal economic N management requires correct and timely on‐farm assessment of crop N status to detect N deficiency or excess. Optical sensors are promising tools to assess crop N status throughout a crop or at critical times. The ability of optical sensor measurements of canopy reflectance (Crop Circle ACS 470) and leaf chlorophyll (SPAD 502 chlorophyll meter) to assess crop N status was evaluated weekly throughout an indeterminate tomato crop. Strong linear relationships with the optical sensor measurements were obtained, throughout most of the crop, for both (a) crop N content for ranges of 1.5–4.5%, and (b) the nitrogen nutrition index (NNI) for ranges of 0.4–1.3. The relationships of the optical sensor measurements to crop NNI were generally equal to or slightly better than with crop N content. Indices based on reflectance in the red, the normalised difference vegetation index (NDVI) and the red vegetation index (RVI), were the best predictors of crop N status in terms of goodness of fit, earliness and maintenance of relationships throughout the crop. SPAD chlorophyll readings and reflectance indices based on reflectance in the green, the normalised difference vegetation index on greenness (GNDVI) and the green vegetation index (GVI), were good indicators of crop N status for most of the crop, but with lower goodness of fit in the latter part of the crop. The linear relationships between sensor indices and readings with NNI or crop N content, each week, demonstrated the potential for using proximal canopy reflectance indices such as NDVI and RVI, and chlorophyll meter for monitoring crop N status of indeterminate tomato crops. Threshold values for optimal crop N nutrition for canopy reflectance indices and for chlorophyll meter readings were derived for each day of measurement from the relationships between optical sensor measurements and NNI by solving for NNI = 1. The threshold values obtained for each index and type of measurement varied during the crop cycle. The approach developed for determining threshold values from NNI can facilitate on‐farm use of optical sensors for monitoring crop N status, by enabling assessment of whether crop N status is excessive, deficient or adequate.     

How can an agri-environmental scheme be designed for farmland bird protection,and what does it mean for the CAP 2023–2027?

Biodiversity loss is recognized as a major global threat. The European Commission has addressed this issue with vigour in its current strategy papers. Farmland birds, such as the lapwing (Vanellus vanellus), whose population has been rapidly declining in Germany, have been particularly affected. To date, the European Union has tried to tackle the problem of biodiversity loss mainly with voluntary agri-environmental schemes (AESs), which are financed by the European Agricultural Fund for Rural Development (EAFRD). However, only a small fraction of agricultural land is enrolled in such programs. We identify the possible drivers and inhibitors of farmers’ acceptance of a potential AES that, if introduced, could contribute to lapwing conservation. Our analysis is based on a discrete choice experiment conducted with 252 arable farmers in Germany. The results suggest that scheme attributes tied with EAFRD compliance, i.e., a minimum participation period of five years and the nature of the relevant sanctions regime, reduce farmers’ potential acceptance of the proposed AES. Furthermore, farmers and farm characteristics have an influence on preferences for specific AES attributes. Finally, this article outlines how the identified weaknesses of AES may be addressed in the new “Green Architecture” of the Common Agricultural Policy 2023–2027.     

Effect of Soil Water Stress on Osmotic Adjustment and Elongation Growth of Wheat Leaves

The results of the experiment showed that leaf elongation rate in two wheat cultivars decreased under soil water stress. Rewatering after water stress, growth restoration.of “Changle No.5” was faster than that of “Lumai No.5”. The osmotic adjustment ability of leaves in these two wheat cultivars increased to 0.41MPa for “Changle No.5” and 0.33MPa for “Lumai No.5” as water potential decreased. At the same leaf elongation rate water potential and osmotic potential of “Changle No5” decreased more than that of “Lumai No.5” Leaf elongation rate fell to zero as water potential and osmotic potential were –1.50MPa and –1.70MPa for “Changle No.5” and –1.20MPa and –1.30MPa for “Lumai No.5” The threshold turgor pressure of elongation growth in leaf cell was different being 0.22MPa for “Changle No.5’ and 0.15MPa for “Lumai No.5”. The difference in the gross extensible coefficient of growing leaf was very small.     

Circadian Rhythm of Blood Pressure Challenges Office Values as the “Gold Standard” in the Diagnosis of Gestational Hypertension

Despite poor sensitivity and specificity, office blood pressure (BP) determinations are still the “gold standard” for diagnosing gestational hypertension. This prospective blind study evaluates the prognostic value of office values as compared with ambulatory monitoring in pregnancy. We analyzed 2175 BP series systematically sampled from 355 non-preeclamptic pregnant women for 48 h every 4 wks from the first hospital visit until delivery. Women were divided for comparative purposes into three groups: “detected” gestational hypertension, defined on the basis of casual clinical BP>140/90 mm Hg after 20 wks of gestation and hyperbaric index (area of BP excess above the upper limit of a time-specified tolerance interval adjusted for the circadian pattern of the reference population) consistently above the threshold for diagnosing hypertension in pregnancy; “undetected” gestational hypertension, women with office BP<140/90 mm Hg but hyperbaric index consistently above the threshold for diagnosis; and normotension, women with both office values and hyperbaric index below the respective thresholds for diagnosis. Small and insignificant differences in the 24 h mean BP between “detected” and “undetected” gestational hypertension is observed in all trimesters, in contrast with highly significant differences between these two groups and normotensive pregnancies. Normotensive women are characterized by highly significant lesser incidence by 60% in preterm delivery, 70% in intrauterine growth retardation, and 50% in delivery by cesarean section (P<0.001) compared with women with “detected” and “undetected” gestational hypertension (P>0.715). In pregnancy, the hyperbaric index is markedly superior to office BP measurements for diagnosis of what should be truly considered gestational hypertension, and for prediction of the outcome of pregnancy.     

Fractality, “coastline of the universe”, movement of the Earth, and “macroscopic fluctuations”

The evolution of views on the nature of the phenomenon of “macroscopic fluctuations”, discovered about sixty years ago as “anomalous scattering of results” of measuring the actomyosin enzyme activity, is traced in the paper. Since then, the general character of this phenomenon was stated because it was found in measurements of processes of different nature, being caused by movement of the Earth in heterogeneous and anisotropic space-time. The paper is dedicated to the memory of L.A. Blumenfeld: a many-decade discussion with him supported these investigations.