Structure and development of the scale case ofMallomonas adamas (Synurophyceae)

Summary The structure and development of the elaborate scale case ofMallomonas adamas (Synurophyceae) was studied throughout the cell cycle. Immediately following division, scale cases normally possess 30 siliceous scales, or 5 rows of 6 scales each. Scale rows overlap one another and spiral around the cell in a clockwise direction when viewed from either end of the cell. Throughout interphase, a duplicate set of 30 scales is manufactured and secreted into the existing scale case in a precise sequence, resulting in a scale case with 60 scales, or 5 rows of 12 scales each. Scales are not added to the scale case in rows, but individually positioned within the cytoplasm and inserted one at a time over the entire surface of the cell. Scales appear to occupy specific positions in the scale case. Scale cases are dynamic cell coverings, their elaborate patterning being maintained throughout cell growth and during division when half the parental scales are inherited by each daughter cell.     

Determination of age and growth in stream fishes of northern Borneo

Synopsis In mildly seasonal tropical climates, the pattern of marks on hard body parts of fishes may be difficult to interpret and unreliable for age determination. Many tropical fishes are now known to have annual peaks in spawning activity which are reflected in their length-frequency distributions. Although scales from freshwater stream fishes in the Baram River system of Sarawak, Malaysia revealed no clearly discernable pattern of annual marks, age classes could be identified from the length-frequency histograms with sufficient accuracy for production to be calculated. For management of the numerous and relatively unknown species present in rapidly developing tropical fisheries, serial quantitative samples at the same localities and inter-locality comparisons of length-frequency histograms may offer a fast and effective method of establishing the necessary age structures.     

Characteristic length scales of spatial models in ecology via fluctuation analysis

A technique of fluctuation analysis is introduced for the identification of characteristic length scales in spatial models, with similarities to the recently introduced methods using correlations. The identified length scale provides the optimal size to extract non-trivial large-scale behaviour in such models. The method is demonstrated for three biological models: genetic selection, plant competition and a complex marine system; the first two are coupled map lattices and the last one is a cellular automaton. These cover the three possibilities for asymptotic (long time) dynamics: fixation (the system converges to a fixed point); statistical fixation (the spatial statistics converge to fixed values); and complex statistical structure (the statistics do not converge to fixed values). The technique is shown to have an additional use in the identification of aggregation or dispersal at various scales. The method is rigorously justifiable in the cases when the system under analysis satisfies the FKG (Fortuin-Kasteleyn-Ginibre) property and has a fast decay of correlations. We also discuss the connection between the fluctuation analysis length scale and hydrodynamic limits methods to derive large scale equations for ecological models. <br>     

Can biodiversity monitoring schemes provide indicators for ecosystem services?

Recently, the science and policy agenda on biodiversity moved to include ecosystem services assessments and it is recognised that for determining the effectiveness and progress of policy frameworks monitoring is crucial.Within European monitoring schemes, data is collected following different sampling protocols for a range of biodiversity or context related aspects; from EU-wide general land cover mapping to red list species within Annex I habitats. In this paper, we analysed field instructions of seven monitoring schemes on the extent to which they can provide data on the provision of ecosystem services and what additional information may be needed for future monitoring of ecosystem services.We compared seven monitoring schemes (i.e. CORINE Land Cover, Land Use Cover Area Survey (LUCAS), European Biodiversity Observation Network (EBONE), biodiversity monitoring on organic and low-input farming systems (BioBio), National Inventory of the Landscape of Sweden (NILS) and Pan-European Common Birds Monitoring (PECBM) and UK Butterfly monitoring (UK-BM)) by scoring the quality of recorded parameters and the adequacy of sampling protocols for ecosystem service monitoring.All the examined schemes were able to provide some parameters on ecosystem services, but the quality of the parameters on average did not exceed the level of qualitative data. Additionally, the divergence between the sampling designs of the schemes and the spatial characteristics of ecosystem services reduced the potential monitoring value of all schemes. Monitoring schemes including a range of sampling methods, scales and included the recording of data on habitats, such as EBONE, BioBio and NILS, provided the best data on the provision of ecosystem services.We conclude that improvement of the monitoring of ecosystem services is hindered by several knowledge gaps: (1) a robust definition and conceptual framework of ecosystem services; (2) the linkage between biodiversity and ecosystem services; and (3) the interpretation of monitoring data.In addition to ecosystem service monitoring, biodiversity monitoring unremittingly remains very important, at least to identify trade-offs between the management for services and the resulting biodiversity status.