Importance of thermophilous habitats for protection of wild bees (Apiformes)

Research on wild bees (Apiformes) was conducted in the Lower Oder Valley (NW Poland) at Natura 2000 sites near the border between Poland and Germany. The analysis involved 3 landscape types with xerothermic and sandy grasslands, differing in the proportion of woody vegetation. In total, we collected there 4158 specimens of Apiformes, representing 180 species. We have proved that mid-forest grasslands with a high proportion of thermophilous broad-leaved forests and xerothermic shrub communities are equally attractive to wild bees as open habitats (sandy grasslands, xerothermic grasslands/heaths). We observed varied responses of wild bee species with specific functional characteristics to increasing proportion of woody vegetation. The grasslands surrounded by forests were characterized by the highest number of cleptoparasitic species. In contrast, solitary and social bee species preferred forest-steppe habitats. However, in open habitats, solitary bees were the most abundant. Moreover, open habitats were distinguished by the highest number and abundance of rare species. Active protection of thermophilous grasslands is crucial for biodiversity conservation, also with respect to the natural resources of Apiformes. Preservation of biodiversity in threatened xerothermic and sandy grasslands should be one of the key objectives of nature conservation in European countries. Currently, more and more actions are undertaken to improve their condition and to restore those particularly valuable and threatened habitat types

Optimal spatiotemporal scales to aggregate satellite ocean color data for nearshore reefs and tropical coastal waters: two case studies

Remotely sensed ocean color data are useful for monitoring water quality in coastal environments. However, moderate resolution (hundreds of meters to a few kilometers) satellite data are underutilized in these environments because of frequent data gaps from cloud cover and algorithm complexities in shallow waters. Aggregating satellite data over larger space and time scales is a common method to reduce data gaps and generate a more complete time series, but potentially smooths out the small-scale, episodic changes in water quality that can have ecological influences. By comparing aggregated satellite estimates of Kd(490) with related in-water measurements, we can understand the extent to which aggregation methods are viable for filling gaps while being able to characterize ecologically relevant water quality conditions. In this study, we tested a combination of six spatial and seven temporal scales for aggregating data from the VIIRS instrument at several coral reef locations in Maui, Hawai‘i and Puerto Rico and compared these with in situ measurements of Kd(490) and turbidity. In Maui, we found that the median value of a 5-pixels, 7-days spatiotemporal cube of satellite data yielded a robust result capable of differentiating observations across small space and time domains and had the best correlation among spatiotemporal cubes when compared with in situ Kd(490) across 11 nearshore sites (R2 = 0.84). We also found long-term averages (i.e., chronic condition) of VIIRS data using this aggregation method follow a similar spatial pattern to onshore turbidity measurements along the Maui coast over a three-year period. In Puerto Rico, we found that the median of a 13-pixels, 13-days spatiotemporal cube of satellite data yielded the best overall result with an R2 = 0.54 when compared with in situ Kd(490) measurements for one nearshore site with measurement dates spanning 2016–2019. As spatiotemporal cubes of different dimensions yielded optimum results in the two locations, we recommend local analysis of spatial and temporal optima when applying this technique elsewhere. The use of satellite data and in situ water quality measurements provide complementary information, each enhancing understanding of the issues affecting coastal ecosystems, including coral reefs, and the success of management efforts

Linking Land and Sea Through an Ecological-Economic Model of Coral Reef Recreation

This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this recordCoastal zones are popular recreational areas that substantially contribute to social welfare. Managers can use information about specific environmental features that people value, and how these might change under different management scenarios, to spatially target actions to areas of high current or potential value. We explored how snorkelers' experience would be affected by separate and combined land and marine management actions in West Maui, Hawaiʻi, using a Bayesian belief network (BBN) and a spatially explicit ecosystem services model. The BBN simulates the attractiveness of a site for recreation by combining snorkeler preferences for coastal features with expert opinions on ecological dynamics, snorkeler behavior, and management actions. A choice experiment with snorkelers elucidated their preferences for sites with better ecological and water-quality conditions. Linking the economic elicitation to the spatially explicit BBN to evaluate land-sea management scenarios provides specific guidance on where and how to act in West Maui to maximize ecosystem service returns. Improving coastal water quality through sediment runoff and cesspool effluent reductions (land management), and enhancing coral reef ecosystem conditions (marine management) positively affected overall snorkeling attractiveness across the study area, but with differential results at specific sites. The highest improvements were attained through joint land-sea management, driven by strong efforts to increase fish abundance and reduce sediment; however, the effects of management at individual beaches varied.Pacific Islands Climate Science Center (PICSC)US Department of Agriculture National Institute of Food and Agriculture (USDA-NIFA)National Oceanic and Atmospheric Administration Coral Reef Conservation ProgramNational Socio-Environmental Synthesis Center (SESYNC

On plexus representation of dissimilarities

Correspondence analysis has found widespread application in analysing vegetation gradients. However, it is not clear how it is robust to situations where structures other than a simple gradient exist. The introduction of instrumental variables in canonical correspondence analysis does not avoid these difficulties. In this paper I propose to examine some simple methods based on the notion of the plexus (sensu McIntosh) where graphs or networks are used to display some of the structure of the data so that an informed choice of models is possible. I showthat two different classes of plexus model are available. These classes are distinguished by the use in one case of a global Euclidean model to obtain well-separated pair decomposition (WSPD) of a set of points which implicitly involves all dissimilarities, while in the other a Riemannian view is taken and emphasis is placed locally, i.e., on small dissimilarities. I showan example of each of these classes applied to vegetation data

The influence of hydrological regimes on sex ratios and spatial segregation of the sexes in two dioecious riparian shrub species in northern Sweden

River management practices have altered the hydrological regimes of many rivers and also altered the availability of regeneration niches for riparian species. We investigated the impact of changed hydrological regimes on the sex ratios and the Spatial Segregation of the Sexes (SSS) in the dioecious species Salix myrsinifolia Salisb.–phylicifolia L. and S. lapponum L. by studying the free-flowing Vindel River and the regulated Ume River in northern Sweden. We surveyed sex ratios of these species in 12 river reaches on the Vindel River and in 17 reaches on the Ume River. In addition, we surveyed the sex and location above mean river stage of 1,002 individuals across both river systems to investigate the SSS of both species. Cuttings were collected from male and female individuals of S. myrsinifolia–phylicifolia from both rivers and subjected to four different water table regimes in a greenhouse experiment to investigate growth response between the sexes. We found an M/F sex ratio in both river systems similar to the regional norm of 0.62 for S. myrsinifolia–phylicifolia and of 0.42 for S. lapponum. We found no evidence of SSS in either the free-flowing Vindel River or the regulated Ume River. In the greenhouse experiment, hydrological regime had a significant effect on shoot and root dry weight and on root length. Significantly higher shoot dry weights were found in females than in males and significantly different shoot and root dry weights were found between cuttings taken from the two rivers. We concluded that changed hydrological regimes are likely to alter dimensions of the regeneration niche and therefore to influence sex ratios and SSS at an early successional stage, making it difficult to find clear spatial patterns once these species reach maturity and can be sexed

Conditions of the occurrence of Anemone sylvestris in a kettle hole in North-Eastern Poland

The research, in 2004, was focused on the whole population of Anemone sylvestris (Snowdrop Windflower) present in the area of a kettle hole (0.8 km2) in north-eastern Poland (52°50’00’’N; 23°11’20’’E). The location of 56 clumps of generative specimens was surveyed. They numbered from several to approx. 1500 specimens. The number of generative specimens in this population exceeded 10 000. On account of this, it is a unique stand of A. sylvestris in Poland. The relationship between the occurrence of the Snowdrop Windflower and the presence of kame hills and ridges has been proven. Low slopes of kame with an inclination of 10-20o, and a north-eastern or eastern exposition has been found as the local ecological optimum for this species. Research carried out in 1970-2001 on 5 permanent plots (25 m2 each) has shown that: 1) Anemone sylvestris is an essential element of xerothermic grasslands of the order Festucetalia valesiacae; 2) the species suddenly withdraws from the parts of land on which woody species have already reached the shrub layer; 3) the greatest danger for the population of A. sylvestris in this area is the process of secondary succession initiated by the discontinuation of grazing on the kame hills

Flora and habitat of potato pits on kame hills in North-Eastern Poland

The research was carried out in north-eastern Poland in the vicinity of the village of Haćki (52°50’00’’N; 23°11’20’’E). This area is distinguished by an exceptionally numerous agglomeration of kames (10). Previous archaeological and soil research showed that kames have been inhabited by man from the iron age, and that the following stages of colonization are reflected in three levels of fossil soils. In modern times local people use the base of kames for the storage of potatoes over the winter. The potato pits are a cultural curiosity found only in this area. They are dug out in the cohesive, fine-grained substratum, which is the building material of kames, down to 1.5-2 m deep. Research plots (16) with a surface area of about 2-5 m2 were established in the potato pits in 1990. In the summer of the same year 16 phytosociological surveys were performed and soil samples taken. The investigated habitats are characterized by very low humidity. The concentration of carbon in the samples from potato pits dug out at the foot of a kame hill (the site of a settlement in the past) results probably from the occurrence of soil from the Roman period. At the present time the pits are covered by poor ruderal flora (approx. 10 species in one phytosociological survey). It is distinguished from other communities of such type by a low participation of species occurring in the xerothermic grasslands