Structuring of plant communities across agricultural landscape mosaics: the importance of connectivity and the scale of effect

Background Plant communities of fragmented agricultural landscapes, are subject to patch isolation and scale-dependent effects. Variation in configuration, composition, and distance from one another affect biological processes of disturbance, productivity, and the movement ecology of species. However, connectivity and spatial structuring among these diverse communities are rarely considered together in the investigation of biological processes. Spatially optimised predictor variables that are based on informed measures of connectivity among communities, offer a solution to untangling multiple processes that drive biodiversity. Results To address the gap between theory and practice, a novel spatial optimisation method that incorporates hypotheses of community connectivity, was used to estimate the scale of effect of biotic and abiotic factors that distinguish plant communities. We tested: (1) whether different hypotheses of connectivity among sites was important to measuring diversity and environmental variation among plant communities; and (2) whether spatially optimised variables of species relative abundance and the abiotic environment among communities were consistent with diversity parameters in distinguishing four habitat types; namely Crop, Edge, Oak, and Wasteland. The global estimates of spatial autocorrelation, which did not consider environmental variation among sites, indicated significant positive autocorrelation under four hypotheses of landscape connectivity. The spatially optimised approach indicated significant positive and negative autocorrelation of species relative abundance at fine and broad scales, which depended on the measure of connectivity and environmental variation among sites. Conclusions These findings showed that variation in community diversity parameters does not necessarily correspond to underlying spatial structuring of species relative abundance. The technique used to generate spatially-optimised predictors is extendible to incorporate multiple variables of interest along with a priori hypotheses of landscape connectivity. Spatially-optimised variables with appropriate definitions of connectivity might be better than diversity parameters in explaining functional differences among communities.

Levels of Sophistication in Elementary Students’ Understanding of Polygon Concept and Polygons Classes

This paper reports sophistication levels in third grade children’s understanding of polygon concept and polygon classes. We consider how children endow mathematical meaning to parts of figures and reason to identify relationships between polygons. We describe four levels of sophistication in children’s thinking as they consider a figure as an example of a polygon class through spatial structuring (the mental operation of building an organization for a set of figures). These levels are: (i) partial structuring of polygon concept; (ii) global structuring of polygon concept; (iii) partial structuring of polygon classes; and (iv) global structuring of polygon classes. These levels detail how cognitive apprehensions, dimensional deconstruction, and the use of mathematical language intervene in the mental process of spatial structuring in the understanding of the classes of polygons.

Conceptual tasks of spatial structuring of ecological and economic fundamentals of the agricultural sector in the context of cross-border cooperation

The article identifies the relevance and problems of cross-border cooperation in the context of the agricultural sector. Ukrainian-Polish cross-border cooperation in the agricultural sphere is studied, the positive aspects of cooperation are noted. Conceptual tasks of cross-border cooperation in the context of agrosphere are formed. The ecological and economic bases of cross-border cooperation in the agrosphere are considered, the forms of cross-border cooperation in relation to these principles are determined. The current state of cross-border cooperation in Ukraine is considered. Prospects for further cross-border cooperation are described.

Socio-Economic Development of Russia and Problems of Spatial Structuring

The transition to a new social order is accompanied by changes in the methodology and functioning of socio-economic systems. The modern period of the development of scientific research is characterized by a variety of recommendations and opinions of scientists on the strategy and tactics of managing economic development. It is difficult to reach a consensus in choosing the most effective means of economic policy, taking into account the peculiarities of the current internal and external situation. For the functioning of the national economy of Russia, it is important to reach a consensus in the applied methods and instruments of state regulation of economy in the territorial context: macroregions, regions, municipalities. The necessary conditions for the successful implementation of state plans and programs are the coordination of the activities of economic entities, production cooperation, and the stability of economic ties. The development and implementation of effective measures are relevant to current scientific problems and are in the center of public attention. The aim of the research is to study the features of spatial structuring in accordance with regional policy and national strategic documents, to conduct a content analysis of the socio-economic situation of Russian territories of different ranks. The expected result is the preparation of recommendations for the development of certain aspects of regional economic research. On the basis of factual material on federal districts, the work examines the possibilities of the practical application of methods and tools of regional economic science to achieve high results in business practice. Using general scientific and applied methods, a conceptual vision of the necessary changes in the priorities of spatial development and the system of strategic planning documents is presented. Based on the objective process of digitalization, current trends have been identified and possible innovations in approaches to structuring space at the subnational level have been formulated, and possible directions of transformation in the management of regional socio-economic systems have been substantiated.

Spatio-temporal persistence of zooplankton communities in the Gulf of Alaska

Spatial structuring of mid-trophic level forage communities in the Gulf of Alaska (GoA) is poorly understood, even though it has clear implications for the health of fisheries and marine wildlife populations. Here, we test the hypothesis that summertime (May-August) mesozooplankton communities are spatially-persistent across years of varying ocean conditions, including during the marine heatwave of 2014–2016. We use spatial ordinations and hierarchical clustering of Continuous Plankton Recorder (CPR) sampling over 17 years (2000–2016) to (1) characterize typical zooplankton communities in different regions of the GoA, and (2) investigate spatial structuring relative to variation in ocean temperatures and circulation. Five regional communities were identified, each representing distinct variation in the abundance of 18 primary zooplankton taxa: a distinct cluster of coastal taxa on the continental shelf north of Vancouver Island; a second cluster in the western GoA associated with strong currents and cold water east of Unimak Pass; a shelf break cluster rich in euphausiids found at both the eastern and western margins of the GoA; a broad offshore cluster of abundant pelagic zooplankton in the southern GoA gyre associated with stable temperature and current conditions; and a final offshore cluster exhibiting low zooplankton abundance concentrated along the northeastern arm of the subarctic gyre where ocean conditions are dominated by eddy activity. When comparing years of anomalous warm and cold sea surface temperatures, we observed change in the spatial structure in coastal communities, but little change (i.e., spatial persistence) in the northwestern GoA basin. Whereas previous studies have shown within-region variability in zooplankton communities in response to ocean climate, we highlight both consistency and change in regional communities, with interannual variability in shelf communities and persistence in community structure offshore. These results suggest greater variability in coastal food webs than in the central portion of the GoA, which may be important to energy exchange from lower to upper trophic levels in the mesoscale biomes of this ecosystem.