Nitrogen and Phosphorus in the Finnish Energy System, 1900–2003

In producing power, humans move the nutrients nitrogen (N) and phosphorus (P) from their long‐term geological and biological stocks and release or emit them in soil, water, and the atmosphere. In Finland, peat combustion is an important driver of N and P fluxes from the environment to human economy. The flows of N and P in the Finnish energy system were quantified with partial substance flow analysis, and the driving forces of emissions of nitrogen oxides (NOx) were analyzed using the ImPACT model. In the year 2000 in Finland, 140,000 tonnes of nitrogen entered the energy system, mainly in peat and hard coal. Combustion released an estimated 66,000 tonnes of N as nitrogen oxides (NOx) and nitrous oxides (N2O) and another 74,000 tonnes as elemental N2. Most of the emissions were borne in traffic. At the same time, 6,000 tonnes of P was estimated to enter the Finnish energy system, mostly in peat and wood. Ash was mainly used in earth construction and disposed in landfills; thus negligible levels of P were recycled back to nature. During the twentieth century, fuel‐borne input of N increased 20‐fold, and of P 8‐fold. In 1900–1950, the increasing use of hard coal slowly boosted N input, whereas wood fuels were the main carrier of P. Since 1970, the fluxes have been on the rise. NOx emissions leveled off in the 1980s, though, and then declined in conjunction with improvements in combustion technologies such as NOx removal (de‐NOx) technologies in energy production and catalytic converters in cars.     

Why are there few algae on snail shells? The effects of grazing,nutrients and shell chemistry on the algae on shells of Helisoma trivolvis

1. Freshwater snails often lack visible growths of algae on their shells. We tested three possible mechanisms that may account for this (grazing, snail-derived nutrients and chemical defences), using the ramshorn snail Helisoma trivolvis .
2. The experiments were carried out in floating plastic enclosures in a pond and comprised seven treatments. Grazing treatments were: a lone snail (ungrazed, as self-grazing does not occur), Helisoma with conspecifics, Helisoma with the co-occurring pond snail Physa sp., empty shells with Helisoma , and ungrazed empty shells. Nutrient effects were possible in all treatments with occupied shells (lone snail; Helisoma with conspecifics, and with Physa ) versus absent in other treatments. Testing for chemical defences compared algae on fresh empty shells, weathered shells (outer organic periostracum layer absent) and boiled fresh shells (with denaturization of susceptible proteins).
3. Diatoms dominated algal assemblages on snail shells. Although the upright diatom Gomphonema gracile was abundant on all shells, it was dominant on the shells of snails housed with other snail grazers (either Helisoma or Physa ).
4. Only the lone snail (nutrients but no grazing) showed higher algal biomass, so presumably any nutrient effect in the treatments with grazers was masked. Both Helisoma and Physa were observed apparently grazing on Helisoma shells, and consequently algal biomass in multi-snail treatments was similar to that on empty shells. Scanning electron microscopy revealed that algal density was highest near the aperture of live snails, but not empty shells; this is consistent with a nutrient addition effect. There was no evidence of chemical defences against algal growth.
5. In soft-bottomed freshwater habitats with abundant snails, shells of living snails provide nutrient-augmented substrata that may indirectly boost overall snail production.     

Ecology of bdelloids: how to be successful

Bdelloids inhabit many different environments. The entire taxon is an order belonging to the phylum Rotifera. In spite of its wide distribution, it has a very uniform morphology, suggesting that natural selection has had almost no effect on its morphological characteristics.This paper reviews the geographical and ecological distributions of bdelloids and their ability to tolerate different conditions is discussed. Two characteristics account for the wide distribution of bdelloids, parthenogenetic reproduction and their ability to withstand unfavorable conditions through anhydrobiosis. The former is an apomictic thelytoky which may ensure genetic homogeneity within clones. However, evidence which suggests variability among and within parthenogenetic clones is discussed. Some recent experimental evidence indicates that anhydrobiosis does not affect the life history of the surviving individuals. The effects of anhydrobiosis on bdelloid populations are considered.     

Evolutionary steps of ecophysiological adaptation and diversification of ruminants: a comparative view of their digestive system

Summary A review is made of the ruminant digestive system in its morphophysiological variations and adaptations relating to foraging behaviour, digestive physiology, to interactions between plants and ruminants and to geographic and climatic diversity of ruminants' ecological niches. Evidence is provided for evolutionary trends from an extreme selectivity mainly for plant cell contents and dependence upon a fractionated fore- and hindgut fermentation, to an unselective intake of bulk roughage subjected to an efficient plant cell wall fermentation, mainly in the forestomachs. The review is based on detailed comparative morphological studies of all portions of the digestive system of 65 ruminant species from four continents. Their results are related to physiological evidence and to the classification of all extant ruminants into a flexible system of three overlapping morphophysiological feeding types: concentrate selectors (40%), grass and roughage eaters (25%) and intermediate, opportunistic, mixed feeders (35%). Several examples are discussed how ruminants of different feeding types are gaining ecological advantage and it is concluded that ruminants have achieved high levels of digestive efficiency at each evolutionary stage, (including well-documented seasonal adaptations of the digestive system) and that ruminant evolution is still going on. Deductions made from the few domesticated ruminant species may have, in the past, biased scientific evaluation of the free-ranging species' ecology. The main threat to a continuous ruminant evolution and diversity appears to be man's neglect for essential ecological interactions between wild ruminants and their specific habitats, which he alters or destroys.Abbreviations bw body weight - CS concentrate selector - DFC distal fermentation chamber (distended caecocolon) - GR grass and roughage eater - IM intermediate (mixed) feeder - PFC proximal fermentation chamber (ruminoreticulum/forestomachs) - RR Ruminoreticulum - SCFA Short-chain fatty acis (acetic, butyric, propionic acid set free by rumen bacteriae) - SE Surface enlargement (of absorptive mucosa) Supported by German Research Community grant DFG Ho 273/6Dedicated to Professor Dr. Dr. h.c. Dietrich Starck on the occasion of his 80th birthday     

Associations between gastropod shell characteristics and egg production in the hermit crab Pagurus longicarpus

Summary Two populations (salt marsh and seagrass bed) of the hermit crab Pagurus longicarpus were sampled to examine associations between shell characteristics and egg production. Multivariate statistical analyses controlled for crab size and time of year, variables that otherwise could be confounded with shell effects. Although correlations between shell characteristics and reproduction existed in both populations, generalizations could not be made because associations varied within and between populations. Shell species was not associated with a female's reproductive state (i.e., whether or not she was barren when sampled) in either population. In the seagrass population, medium-large and large females occupying severely damaged or fouled shells were half as likely to be reproductive as females occupying other shell conditions. However, there was no association between shell condition and reproductive state for small and small-medium females in the seagrass population or among all females in the salt marsh population. In the seagrass population, small through medium-large reproductive females occupied shells more similar to their predicted shell size, regardless of whether the occupied shell was relatively small or large, than nonreproductive females. In contrast, relative shell sizes of reproductive and nonreproductive females were similar for large females in the seagrass population and all females in the salt marsh population. Clutch sizes were enhanced for females occupying Polinices duplicatus shells or shells larger than their predicted shell size in the seagrass population. Relative shell size also was associated with clutch size in the salt marsh population, but crabs occupying shells similar to their predicted shell size had the largest clutches.     

Influence ofGlycine max nodulation on the persistence in soil of a genetically markedBradyrhizobium japonicum strain

Since competition with indigenous strains limits nodule occupancy by bacteria applied to seeds, the ecology of Bradyrhizobium inoculum strains used for soybean is of concern. A genetically marked strain,B. japonicum I-110 ARS, was directly enumerated from soil on selective medium. A clear long-term positive influence of even limitedGlycine max nodulation was shown by comparisons of population densities obtained with or without plant removal prior to nodule senescence in the first year and with an incompatible as well as a compatible soybean variety after 5 years.     

Evolutionary trends of the hairy-faceSaguinus in terms of the dental and cranial morphology

Shape variations in the dentition and the cranium were analyzed for sevenSaguinus forms of the hairy-face tamarin by applying the factor analysis method. The results obtained for the dental and cranial measurements were almost consistent with each other. The magnitude of the difference in shape factors between theS. nigricollis group and theS. midas group is appreciably larger than that between the former group and theS. mystax group. If the ancestral geographic centre of origin is postulated as being within the region which is inhabited by the livingS. nigricollis group, the morphological distances between any pairs of groups correlate well with the geographic distances between them. Concerning the dental and cranial morphologies, the physical changes in the three species group probably took place in two directions; that is, from theS. nigricollis group to theS. mystax group, and from theS. nigricollis group to theS. midas group. The forms belonging to each species group are more closely related to each other, with the exception ofS. imperator in theS. mystax group. The uniqueness ofS. imperator was clearly demonstrated by factor analysis and distance analysis. In theS. mystax group, although still hypothetical,S. imperator may have been related only through the basic ancestral stock toS. labiatus andS. mystax.     

Weed macaques: The evolutionary implications of macaque feeding ecology

Patterns of feeding ecology among the living macaques conform poorly with recognized phyletic distinctions within the genus because there is an important ecological division which cross-cuts phyletic groupings. This division, between weed species and non-weed species, is based on the differing abilities of macaques to tolerate and even prosper in close association with human settlements. Based on available information about their ecology in the wild, we tentatively assign macaque species to these two categories. Finally, we consider the implications of our argument for scenarios of the initial spread of the macaques.     

Feeding ecology of the proboscis monkey (Nasalis larvatus)

Proboscis monkey (Nasalis larvatus) feeding behavior and ecology were studied at the Natai Lengkuas Station, Tanjung Puting National Park, Kalimantan Tengah, Indonesia. Data on feeding behavior were collected using scan sampling during group follows. Three vegetational plots containing 1,732 trees were established and monitored monthly for changes in fruit, flower, and young leaf production. Basal area and canopy cover were calculated and used in estimating food abundance. Proboscis monkeys were found to be folivore/frugivores, specializing in seed consumption. At least 55 different plant species were used as food sources, with a marked preference for Eugenia sp. 3/4,Ganua motleyana and Lophopetalum javanicum. These tree species were among the most frequent and most dominant. However, proboscis monkeys were selective feeders; use of tree species as food sources was not based simply on relative density. During times of low food abundance and/or availability proboscis monkeys switched dietary strategies and increased dietary diversity. The average total home range was estimated to be 130.3 ha, with an average group density of 5.2 groups per km². The average biomass per km² was estimated to be 499.5 kg. Given their high biomass and predilection for consuming seeds of dominant species, proboscis monkeys may help to maintain and increase vegetational diversity.     

Research perspectives and the anomalous status of modern ecology

Ecology has often been characterized as an immature scientific discipline. This paper explores some of the sources of this alleged immaturity. I argue that the perception of immaturity results primarily from the fact that historically ecologists have based their work upon two very different approaches to research.