Neue Giraffenhaltung im Opel-Zoo Kronberg.

The „Africa Savanna“- exhibit is described. The biggest investment of the Opel-Zoo in recent years was opened for the public on the 50th anniversary of the so-called Georg von Opel - Freigehege für Tierforschung on September 16th, 2006. The developed area covers about 22500 m² and includes in addition to the animal related buildings, a new restaurant, a new main entrance and a new administration building. The mostly moated outside exhibit of about 10000 m² is dominated by artificial baobab tree. A waterhole of 200 m² separates the exhibit from the restaurant. Due to fairly long winters the inside area for the giraffes is rather large, so they can be kept as a herd, even when they must stay inside. Visitors can enter a small area of the giraffe house and may watch the animals through glass. The off-exhibit area for the zebras, gnus and impalas has 18 equal stables of 10 m² each. Five introduction pens connect the new animal house with the outside exhibit.This article also informs about the giraffe keeping history at Kronberg since 1961 and tells about the experiences made with the new development during the first year of use.     

Dynamic response of woody vegetation on fencing protection in semi-arid areas; Case study: Pilot exclosure on the Firmihin Plateau,Socotra Island

Woody vegetation dynamics and Dracaena cinnabari regeneration have been studied for five years in the conditions of Socotra Island. Woody plants were measured regularly inside and outside the exclosure area, and the growth and survival of D. cinnabari seedlings were observed. In the exclosure of about 1000 m² a total of 49 species were identified, including 23 endemics, growing in the average density of 3.82 specimens per m². The fenced area was overgrown relatively rapidly by dense grass cover – reaching approx. 2.7 t/ha. Species growth dynamics inside and outside the exclosure shows that grazing had a marked impact, leading to the elimination of trees and shrubs. All grazed species grew noticeably in the exclosure, in the average of 50 cm in 5 years. D. cinnabari as the dominant flagship species of Socotra has been studied with regards to regeneration dynamics. Observations indicate that probability of its seedlings survival increases with their age. No seedlings germinated from the seeds sown in the experiment, however, outplanted seedlings performed relatively well. Field observations show that D. cinnabari seed germination is triggered when the seed reaches a protected micro-habitat with a developed humus layer and high relative humidity in the soil lasts for at least two days.     

In situ and satellite observations of a harmful algal bloom and water condition at the Pearl River estuary in late autumn 1998

Harmful algal blooms (HABs) have posed a serious threat to the aquaculture and fisheries industries in recent years, especially in Asia. During 1998 there were several particularly serious blooms in the coastal waters of south China, which caused a serious damage to aquaculture. We report a massive dinoflagellate bloom near the mouth of Pearl River in November 1998 with analyses of data from both in situ sea water measurements and satellites. A multi-parameter environmental mapping system was used to obtain real-time measurements of water quality properties and wind data through the algal bloom area, which allow us to compare water measurements from inside and outside of the bloom areas. This bloom with high concentrations of algal cells was evident as a series of red colored parallel bands of surface water that were 100–300 m long and 10–30 m wide with a total area of about 20–30 km² by visual. The algal density reached 3.8×10⁷ cells l⁻¹ and the surface chlorophyll-a (Chl-a) concentration was high. The algal species has been identified as Gymnodinium cf. catenatum Graham. The water column in the bloom area was stratified, where the surface temperature was 24–25 °C, the salinity was 18–20%, and the northern wind was about 3–4 m s⁻¹ in the bloom area. The SeaWiFS image has shown high Chl-a area coinciding with the bloom area. The sea surface temperature (SST) image of the Pearl River estuary combined with the in situ measurements indicated that the bloom occurred along a mixing front between cooler lower salinity river water and warmer higher saline South China Sea (SCS) water.     

Patch dynamics of the Mediterranean seagrass Posidonia oceanica: Implications for recolonisation process

Patch dynamics of the Mediterranean slow-growing seagrass Posidonia oceanica was studied in two shallow sites (3–10 m) of the Balearic Archipelago (Spain) through repeated censuses (1–2 year⁻¹). In the sheltered site of Es Port Bay (Cabrera Island), initial patch density (October 2001) was low: 0.05 patches m⁻², and the patch size (number of shoots) distribution was bimodal: most of the patches had less than 6 shoots or between 20 and 50 shoots. Mean patch recruitment in Es Port Bay (0.006 ± 0.002 patches m⁻² year⁻¹) exceeded mean patch loss (0.001 ± 0.001 patches m⁻² year⁻¹), yielding positive net patch recruitment (0.004 ± 0.003 patches m⁻² year⁻¹) and a slightly increased patch density 3 years later (July 2004, 0.06 patches m⁻²). In the exposed site of S’Estanyol, the initial patch density was higher (1.38 patches m⁻², August 2003), and patch size frequency decreased exponentially with size. Patch recruitment (0.26 patches m⁻² year⁻¹) and loss (0.24 patches m⁻² year⁻¹) were high, yielding a slightly increased patch density in the area 1 year later (October 2004, 1.40 patches m⁻²). Most recruited patches consisted of rooting vegetative fragments of 1–2 shoots. Seedling recruitment was observed in Summer 2004 at both sites. Episodic, seedling recruitment comprised 30% and 25% of total patch recruitment in Es Port Bay and S’Estanyol, respectively. Patch survival increased with patch size and no direct removal was observed among patches of 5 shoots or more. Most patches grew along the study, shifting patch distribution towards larger sizes. Within the size range studied (1–150 shoots), absolute shoot recruitment (shoots year⁻¹) increased linearly with patch size (R² = 0.64, p < 4 × 10⁻⁵, N = 125), while specific shoot recruitment was constant (about 0.25 ± 0.05 year⁻¹), although its variance was large for small patches. Given the slow growth rate and the high survival of patches with 5 or more shoots, even the low patch recruitment rates reported here could play a significant role in the colonisation process of P. oceanica.     

Effects of intraspecific competition on growth and photosynthesis of Atriplex prostrata

We investigated the effect of intraspecific competition on growth parameters and photosynthesis of the salt marsh species Atriplex prostrata Boucher in order to distinguish the effects of density-dependent growth inhibition from salt stress. High plant density caused a reduction of 30% in height, 82% in stem dry mass, 80% in leaf dry mass, and 95% in root dry mass. High density also induced a pronounced 72% reduction in leaf area, 29% decrease in length of mature internodes and 50% decline in net photosynthetic rate. The alteration of net photosynthesis paralleled growth inhibition, decreasing from 7.6 ± 0.9 μmol CO₂ m⁻² s⁻¹ at low density to 3.5 ± 0.4 μmol CO₂ m⁻² s⁻¹ at high density, indicating growth inhibition caused by intraspecific competition is mainly due to a decline in net photosynthesis rate. Plants grown at high density also exhibited a reduction in stomatal conductance from 0.7 ± 0.1 mol H₂O m⁻² s⁻¹ at low density to 0.3 ± 0.1 mol H₂O m⁻² s⁻¹ at high density and a reduction in transpiration rate from 6.0 ± 0.3 mmol H₂O m⁻² s⁻¹ at low density to 4.3 ± 0.3 mmol H₂O m⁻² s⁻¹ at high density. Biomass production was inhibited by an increase in plant density, which reduced the rate of photosynthesis, stomatal conductance and leaf area of plants.     

Development of the “plankton emergence trap/chamber (PET Chamber)”, a new sampling device to collect in situ germinating cells from cysts of microalgae in surface sediments of coastal waters

A simple device was developed to collect germinating cells from settled cysts of microalgae on the sea bottom. This new device – the plankton emergence trap chamber (PET Chamber) – made of a clear acrylic plastic, consists of a top cylinder and a base plate attached to a bottom cylinder. After plugging the bottom cylinder with sediment collected from in situ sea bottom and filling the top cylinder with filtered seawater, the PET Chamber attached to a platform specially made for submerging the chambers is placed on the seafloor. An adequate area of the lateral side of the top cylinder is opened and covered by a plankton net (10 μm mesh) to allow a water exchange between the inside and outside the cylinder. Thus, the PET Chamber can replicate in situ environments, such as temperature, irradiance and dissolved oxygen. Using the PET Chamber, we have succeeded in collecting germinating cells and estimating the germination flux (cells m⁻² day⁻¹) of two dinoflagellates, Alexandrium catenella and Scrippsiella spp., in Ago Bay, Japan. Mircoscopic observations on the samples collected from July to October 2003 revealed fluxes of 124–2022 and 622–3732 cells m⁻² day⁻¹ in A. catenella and Scrippsiella spp., respectively. The data indicate that the new device can detect variations in the number of germinating cells of dinoflagellates. Its sampling ability, coupled with simplicity in deployment and retrieval procedures, can allow one to monitor the in situ emergence from/on the surface sediments of various organisms, that possess resting stages during their life histories, in various coastal waters.     

Effect of different sewage sludge applications on growth and yield of Vigna radiata L. field crop: Metal uptake by plant

The aim of this study was to assess the suitability of sewage sludge use for mung bean {Vigna radiata L. cv. Malviya janpriya (HUM 6)} plants by evaluating the growth, and yield responses, nutritional quality and heavy metal accumulation at different sewage sludge amendment (SSA) rates. Sewage sludge amendment modified the physico-chemical properties of soil by decreasing pH and increasing organic carbon, total iron and heavy metals. Plants showed increments in shoot length, leaf area and total biomass at all SSA rates, but root length increased only up to 9 kg m^?2 SSA rates. Plants grown at different SSA rates showed higher nutrients and heavy metals in seeds, but protein content declined. Sewage sludge application caused about 39, 76 and 60% more yield at 6, 9 and 12 kg m^?2 treatments, respectively. Concentrations of Pb and Ni in grains were higher than the Indian permissible limits at and above 9 kg m^?2 and of Cd at 12 kg m^?2 SSA rates.The study suggests that SSA at a rate lower than 9 kg m^?2 may be recommended due to better fertilizing value for soil and promoting mung bean yield. Higher rate of sewage sludge application leads to elevated accumulation of heavy metals in seeds, which limits the suitability for human consumption.     

Foliage type specific susceptibility to ozone in Picea abies,Pinus cembra and Larix decidua at treeline: A synthesis

Cumulative ozone uptake (COU, mmol m⁻²) and O₃ flux (FO₃, nmol m⁻² s⁻¹) were related to physiological, morphological and biochemical characteristics of field-grown mature evergreen Norway spruce [Picea abies (L.) Karst.], Cembran pine [Pinus cembra L.], and deciduous European larch [Larix decidua Mill.] trees at treeline. The threshold COU causing a statistically significant decline in photosynthetic capacity (A_max) ranged between 19.6 mmol m⁻² in current-year needles of evergreen conifers and 22.0 6 mmol m⁻² in short-shoot needles of deciduous L. decidua subjected to exposure periods of ≥84 and ≥43 days, respectively. The higher O₃ sensitivity of deciduous L. decidua than of evergreen P abies and P. cembra was associated with differences in FO₃ and specific leaf area (SLA), both being significantly higher in L. decidua. FO₃ was 5.9 nmol m⁻² s⁻¹ in L. decidua and 2.7 nmol m⁻² s⁻¹ in evergreen conifers. Species-dependent differences were also related to detoxification capacity expressed through total surface area based concentrations of reduced ascorbate and α-tocopherol that both increased with SLA. Findings suggest that differences in O₃ sensitivity between evergreen and deciduous conifers can be attributed to foliage type specific differences in SLA, the latter determining physiological and biochemical characteristics of the treeline conifers.     

Thermoimaging as a tool for studying light-induced heating of leaves: Correlation of heat dissipation with the efficiency of photosystem II photochemistry and non-photochemical quenching

Thermoimaging – a highly sensitive and non-invasive method of temperature measurement – was applied to explore the role of changing photosynthetic efficiency in light-induced heating of tobacco (Nicotiana tabacum cv. Samsun) leaves. In the absence of evaporative cooling through the stomata, which was achieved by covering leaves with Vaseline, illumination with 50–1400 μM photons m^?2 s^?1 intensity of photosynthetically active radiation resulted in ≈1–5 °C leaf temperature increase in about 2 min. The heating effect showed a non-linear correlation with the extent of non-photochemical quenching (NPQ) resulting in higher leaf temperatures at higher NPQ values. When leaves were adapted to excessive irradiance (1300 μM photons m^?2 s^?1 for 6 h), which resulted in reduction of photosynthetic efficiency and amplification of NPQ the light-induced heating effect was enhanced. The experimental results have been explained on the basis of a simple theoretical model characterizing the balance of energy fluxes in leaves in relation to the efficiency of photosystem II photochemistry and non-photochemical quenching. The role of alternative energy dissipation pathways outside of PSII in the phenomenon of light-induced leaf heating is also discussed.     

Effects of rest grazing on organic carbon storage in Stipa Baicalensis steppe in Inner Mongolia

In order to evaluate the potential effects of rest grazing on organic carbon storage on the Stipa baicalensis steppe in Inner Mongolia, compared the S. baicalensis steppes after rest grazing for 3 years, 6 years, and 9 years, using potassium dichromate heating method, this study analyzed the organic carbon storage of plant and soil in the steppes among different periods of rest grazing. The results indicated that as the rest grazing years prolonged, the biomass included above-ground parts, litters and underground plant parts(roots) of the plant communities all increased, meanwhile the carbon content of the biomass increased with the rest grazing years prolonged. For the zero rest grazing (RG0) steppe and the steppes after a rest grazing of 3 years (RG3a), 6 years (RG6a), 9 years (RG9a), the carbon storage in above-ground parts of plant communities were 42.60 g C/m², 66.33 g C/m², 83.46 g C/m², 100.29 g C/m² respectively; the carbon storage of litters were 7.85 g C/m², 9.12 g C/m², 9.18 g C/m², 11.54 g C/m² separately; the carbon storage of underground plant parts (0–100 cm) were 281.40 g C/m², 576.38 g C/m², 745.33 g C/m², 1279.61 g C/m² respectively; and the carbon storage in 0–100 cm soil were 22991.14 g C/m², 24687.75 g C/m², 26564.86 g C/m²,33041.55 g C/m². The results suggested that as the rest grazing years prolonged, the organic carbon storage in plant communities and soil increased. The carbon storage of underground plant parts and soil organic carbon mainly concentrated in 0–40 cm soil. After rest grazing for 3 years, 6 years, and 9 years, the increased soil organic carbon were as the 81.14%, 85.84%, and 89.46% of the total increased carbon; From the perspective of carbon sequestration cost, the total cost of RG3a, RG6a and RG9a were 2903.40 RMB/hm², 5806.80 RMB/hm², and 8710.20 RMB/hm². The cost reduced with the extension of rest grazing years, 0.17 RMB/kg C, 0.16 RMB/kg C, 0.09 RMB/kg C for RG3a, RG6a and RG9a respectively. From the growth characteristics of grassland plants, the spring was one of the two avoid grazing periods, timely rest grazing could effectively restore and update grassland vegetation, and was beneficial to the sustainable use of grassland. From the available data, the organic carbon storage of RG9a was the highest, while the cost of carbon sequestration was the lowest. Therefore, spring rest grazing should be encouraged to continue for it was proved to be a very efficient grassland use measures.     

Biomorphometric characteristics of different types of sensilla detected on the antenna of Helicoverpa armigera by scanning electron microscopy

A morphometric study on H. armigera antenna showed four styles of sensilla, i.e., styloconica, chaetica, coeloconica, and trichodea, and their numbers were estimated. Sensilla trichodea detect inter and intraspecific communication signals and was the most numerous. They were divided into three types: type I, the longest, with a length of 34.04 ± 3.16 μm and about 2.16 to 2.42 μm in diameter at its base; 2) type II, intermediate, with a length of 22.58 ± 0.77 μm and basal diameter of 1.8–2.52 μm; 3) type III, the shortest sensilla trichodea, with a length of 7.62 ± 0.4 μm and a range in diameter similar to that of type II. The length of the female sensilla trichodea was longer than that of the male. The total number of sensilla trichodea was estimated to be 7520 on the antenna of the female, and 6831 on the male antenna. The lengths of the sensilla trichodea type I and type III were significantly different on male (t = 4.6881, P = 0.0034) and female antenna (t = 18.9852, P = 0.0001). An estimation of the predicted surface area of the most numerous type I on sampled segments between the 12th and 20th segments from a female of H. armigera showed a surface area of 5 × 10³ μm² and a sensillar density of 38 sensilla/10³ μm². The fraction of sensilla-occupied surface area was 0.4 μm².     

Seasonal changes of the introduced Caulerpa racemosa var. cylindracea (Caulerpales,Chlorophyta) at the northwest limit of its Mediterranean range

A study of the meadows of the invasive Caulerpa racemosa var. cylindracea (Sonder) Verlaque, Huisman et Boudouresque was carried out over one year at Marseilles (Provence, France) where the alga is thriving, probably since 1994, in the cold waters of the north western Mediterranean Sea. At an early phase of colonisation, the C. racemosa meadow is characterized by a patchy distribution pattern. Several years are necessary to obtain a dense and continuous meadow. In one area colonized for more than 4 years, C. racemosa has developed a continuous meadow with wide seasonal variations. Maximum development was reached in autumn (biomass: 82 ± 3 g DW m⁻²; length of stolons: 1162 ± 86 m m⁻²; number of apices: 8360 ± 405 m⁻²; number of erect axes: 20955 ± 1499 m⁻²) and the minimum from winter to early spring (respectively, 0.3 ± 0.1 g DW m⁻²; 3 ± 1 m m⁻²; 220 ± 55 apices m⁻²; 35 ± 15 erect axes m⁻²). Seasonal variations in the growth rate were highly significant. The season of high growth lasted from June to October. The apical growth rate of a stolon reached a maximum of 7.5 ± 0.3 mm day⁻¹ in early October, then began to decrease significantly from the end of October to December, before becoming nearly nil from January to early May. Annual net production rate expressed in terms of stolon length and biomass was estimated as 5801 m m⁻² a⁻¹ and 612 g DW m⁻² a⁻¹, respectively. During the growth period, the turnover rate of the C. racemosa stolons was estimated at from 25 to 46 days. The growth rate was closely correlated to the seawater temperature (R² = 0.83), whereas no significant correlation was found between growth and irradiance. During the growth period, a decrease in temperature rapidly affects the growth rate, which soon recovers its earlier level when the temperature rises again. In winter, the growth rate decreased rapidly with the seasonal drop in the seawater temperature. Grazing by fish (Sarpa salpa and Boops boops) can also affect the growth rate from September to December by consumption of the erect axes and stolon apices, enhancing the ramification of stolons. Seasonal changes at Marseilles are much sharper than those reported for warmer Mediterranean localities (French Riviera, Italy, Croatia): in winter and early spring C. racemosa meadows decreased and locally disappeared, leaving a barren substrate. C. racemosa survives the lower winter seawater temperatures of the north-western Mediterranean Sea probably in the form of zygotes and/or small fragments (rhizoids, stolons, propagules).     

Toward scrubbing the bay: Nutrient removal using small algal turf scrubbers on Chesapeake Bay tributaries

Restoration of the Chesapeake Bay poses significant challenges because of increasing population pressure, conversion of farmland to urban/suburban development, and the expense of infrastructure needed to achieve significant and sustained nutrient reductions from agricultural and urban sources. One radical approach for removing non-point source nutrients before they reach the bay is to deploy large-scale algal turf scrubbers along its tributaries. The objective of this study was to determine rates of nutrient removal and algal fatty acid production using small ATS units located along three Chesapeake Bay rivers. Small-scale ATS units (each containing 1 m² growing area) were operated for 5–10 months from April 2007 to April 2008 on three western shore tributaries of the Chesapeake Bay in Maryland: the Bush River, the Patapsco River and the Patuxent River. Total nitrogen (TN) and total phosphorus (TP) removal rates at the Patuxent site fluctuated considerably but averaged 250 mg TN, 45 mg TP m^?2 day^?1 from May to October 2007, then decreased to 16 mg TN, 3 mg TP m^?2 day^?1 from December 2007 to February 2008. Nutrient removal rates at the Bush river site also fluctuated but averaged only 85 mg TN, 10 mg TP m^?2 day^?1 from May to June 2007, before decreasing to <10 mg TN, <1 mg TP m^?2 day^?1 from July to September 2007. The Patapsco River unit began operation in August 2007, reached its maximum removal values of 150 mg TN, 18 mg TP m^?2 day^?1 from mid-October to late-November 2007, then decreased to values of 45 mg TN, 4 mg TP m^?2 day^?1 from November 15, 2007 to mid-April 2008. In the best case (Patuxent site from May to October 2007), daily removal rates of 250 mg N and 45 mg P m^?2 are equivalent to removal rates of 380 kg N and 70 kg P ha^?1 over a 150-day season in Maryland. Fatty acid (FA) content of the harvested material was consistently low (0.3–0.6% of dry weight) and varied little between sites. Mean algal FA production rates (23–54 mg FA m^?2 day^?1) are equivalent to rates of 34–81 kg FA ha^?1 year^?1 based on a 150-day operational season in Maryland.     

Colonization dynamics of biofilm-associated ciliate morphotypes at different flow velocities

The impact of flow velocity on initial ciliate colonization dynamics on surfaces were studied in the third order Ilm stream (Thuringia, Germany) at a slow flowing site (0.09 m s^?1) and two faster flowing sites (0.31 m s^?1) and in flow channels at 0.05, 0.4, and 0.8 m s^?1. At the slow flowing stream site, surfaces were rapidly colonized by ciliates with up to 60 cells cm^?2 after 24 h. In flow channels, the majority of suspended ciliates and inorganic matter accumulated at the surface within 4.5 h at 0.05 m s^?1. At 0.4 m s^?1 the increase in ciliate abundance in the biofilm was highest between 72 and 168 h at about 3 cells cm^?2 h^?1. Faster flow velocities were tolerated by vagile flattened ciliates that live in close contact to the surface. Vagile flattened and round filter feeders preferred biofilms at slow flow velocities. Addition of inorganic particles (0, 0.6, and 7.3 mg cm^?2) did not affect ciliate abundance in flow channel biofilms, but small ciliate species dominated and number of species was lowest (16 species cm^?2) in biofilms at high sediment content. Although different morphotypes dominated the communities at contrasting flow velocities, all functional groups contributed to initial biofilm communities implementing all trophic links within the microbial loop.     

Sex-specific light acclimation of Chara canescens (Charophyta)

Bisexual populations of the charophyte Chara canescens (Desv. et Loisel. in Loisel., 1810) containing male and female individuals are rarely found. Two experiments were carried out to study whether male and female algae from the same site exhibit different physiological capacities, especially with respect to light acclimation.Algae from two different shore levels and from laboratory cultures acclimated to six irradiance conditions (35–500 μmol photons m⁻² s⁻¹) were compared. Field measurements showed that both female and male algae of C. canescens are able to acclimate to daily changes in solar irradiance. The quantum yield of Photosystem II (PSII) decreased with increasing irradiance in the morning and increased with decreasing irradiance in the afternoon. Growth experiments showed increasing growth rates from 35 μmol photons m⁻² s⁻¹ (∼7 mg FW) up to 500 μmol photons m⁻² s⁻¹ (∼27 mg FW) in female and male C. canescens. The irradiance saturation point for photosynthesis (E_k) was about 140 μmol m⁻² s⁻¹ for both sexes within the whole range of acclimation irradiances. The maximum photosynthesis rate at saturating irradiances (P_max) of male algae was highest at E_k, whereas P_max of female algae was highest at 500 μmol photons m⁻² s⁻¹. The photosynthetic efficiency in the light-limited range (α) increased in female C. canescens and decreased in male C. canescens. The ratio of the non-photochemical quenching parameter (NPQ) to the relative electron transport rates rETR_(MT) increased in both sexes with irradiance, but showed a steeper increase in male than in female algae. Pigment analysis showed similar acclimation pattern for male and female C. canescens. Chl a/Chl b ratios of both sexes were constant over the whole range of E_g, whereas Chl a/carotenoid ratios in male and female C. canescens decreased from 70 μmol photons m⁻² s⁻¹ upwards. Pigment analysis pointed out that the carotenes α-, β- and γ-carotene were more prominent in male than in female algae.Our results indicate that female C. canescens are more efficient in light acclimation than male algae from the same site. Nevertheless, further investigations of bisexual C. canescens populations resolving CO₂-uptake mechanisms and/or genetic differences are needed.     

Ground level environmental protein concentrations in various ecuadorian environments: Potential uses of aerosolized protein for ecological research

Large quantities of free protein in the environment and other bioaerosols are ubiquitous throughout terrestrial ground level environments and may be integrative indicators of ecosystem status. Samples of ground level bioaerosols were collected from various ecosystems throughout Ecuador, including pristine humid tropical forest (pristine), highly altered secondary humid tropical forest (highly altered), secondary transitional very humid forest (regrowth transitional), and suburban dry montane deforested (suburban deforested). The results explored the sensitivity of localized aerosol protein concentrations to spatial and temporal variations within ecosystems, and their value for assessing environmental change. Ecosystem specific variations in environmental protein concentrations were observed: pristine 0.32 ± 0.09 μg/m³, highly altered 0.07 ± 0.05 μg/m³, regrowth transitional 0.17 ± 0.06 μg/m³, and suburban deforested 0.09 ± 0.04 μg/m³. Additionally, comparisons of intra-environmental differences in seasonal/daily weather (dry season 0.08 ± 0.03 μg/m³ and wet season 0.10 ± 0.04 μg/m³), environmental fragmentation (buffered 0.19 ± 0.06 μg/m³ and edge 0.15 ± 0.06 μg/m³), and sampling height (ground level 0.32 ± 0.09 μg/m³ and 10 m 0.24 ± 0.04 μg/m³) demonstrated the sensitivity of protein concentrations to environmental conditions. Local protein concentrations in altered environments correlated well with satellite-based spectral indices describing vegetation productivity: normalized difference vegetation index (NDVI) (r² = 0.801), net primary production (NPP) (r² = 0.827), leaf area index (LAI) (r² = 0.410). Moreover, protein concentrations distinguished the pristine site, which was not differentiated in spectral indices, potentially due to spectral saturation typical of highly vegetated environments. Bioaerosol concentrations represent an inexpensive method to increase understanding of environmental changes, especially in densely vegetated ecosystems with high canopies or in areas needing high spatial and temporal resolution. Further research to expand understanding of the applicability of bioaerosol concentrations for environmental monitoring is supported by this pilot study.     

Comparison of Zostera marina and maerl community metabolism

The photosynthetic and repiratory metabolism of Zostera marina and maerl communities was compared, in the same area of the Bay of Brest in March–April, using benthic chambers. P–E curves for both oxygen and carbon were established for bottom irradiances between 0 and 525 μmol m⁻² s⁻¹. An exponential function was fitted to calculate daily production. Community metabolic quotients did not differ for maerl and seagrass beds. Community photosynthetic quotients were significantly higher (1.19) whereas community respiratory quotients were lower (0.70) than 1. Maerl and seagrass bed P–E curves mainly differed by the minimum saturating irradiance (E_k). Net community production was estimated to 26.8 mmol C m⁻² d⁻¹ for Z. marina meadows and 8.6 mmol C m⁻² d⁻¹ for maerl beds. The two communities can, therefore, be considered as autotrophic during the March–April period. Community respiration did not differ between Z. marina meadows and maerl beds, with an average value of 53.8 mmol C m⁻² d⁻¹ during a day. In similar environmental conditions, the production of maerl beds corresponds to approximately one third that of seagrass meadows. The maerl communities, therefore, form productive ecosystems, relevant to temperate coastal ecosystems functioning.     

Diurnal exchanges of CO2 and CH4 across the water–atmosphere interface in a water chestnut meadow (Trapa natans L.)

CH₄ and CO₂ fluxes across the water–atmosphere interface were measured over a 24 h day–night cycle in a shallow oxbow lake colonized by the water chestnut (Trapa natans L.) (Lanca di Po, Northern Italy). Only exchanges mediated by macrophytes were measured, whilst gas ebullition was not considered in this study. Measurements were performed from 29 to 30 July 2005 with short incubations, when T. natans stands covered the whole basin surface with a mean dry biomass of 504 ± 91 g m⁻². Overall, the oxbow lake resulted net heterotrophic with plant and microbial respiration largely exceeding carbon fixation by photosynthesis. The water chestnut stand was a net sink of CO₂ during the day-light period (−60.5 ± 8.5 mmol m⁻² d⁻¹) but it was a net source at night (207.6 ± 6.1 mmol m⁻² d⁻¹), when the greatest CO₂ efflux rate was measured across the water surface (28.2 ± 2.4 mmol m⁻² h⁻¹). The highest CH₄ effluxes (6.6 ± 1.8 mmol m⁻² h⁻¹) were determined in the T. natans stand during day-time, whilst CH₄ emissions across the plant-free water surface were greatest at night (6.8 ± 2.1 mmol m⁻² h⁻¹). Therefore, we assumed that the water chestnut enhanced methane delivery to the atmosphere. On a daily basis, the oxbow lake was a net source to the atmosphere of both CO₂ (147.1 ± 10.8 mmol m⁻² d⁻¹) and CH₄ (116.3 ± 8.0 mmol m⁻² d⁻¹).     

Socio-spatial criteria are important for the establishment of maternal preference in lambs

At lambing, ewes (Ovis aries) tend to isolate themselves from the flock and this is believed to be beneficial to the early relationship with their young. Later, they return to the flock and lambs progressively interact with other conspecifics. This study focused on the importance of isolation and socio-spatial factors on maternal recognition in lambs. All the ewes gave birth in individual 2 m² pens and lambs were able to interact freely with their mothers. A first experiment investigated the role of isolation: INT1 lambs could progressively interact with other mothers and young in a pen which was increased in surface area from birth to 24 h (0–6 h: 1 ewe, 1 litter, 2 m²; 6–12 h: 2 ewes, 2 litters, 4 m²; 12–24 h: 4 ewes, 4 litters, 8 m²); ISO lambs remained in small pens (2 m²) and only with their mothers for 24 h. The lambs were submitted to a 5 min choice test between their own mothers and an alien ewe. At 12 h INT1 lambs, unlike ISO lambs, showed a clear preference for their mothers. ISO lambs still did not show any maternal preference at 24 h. The second experiment investigated the relative importance of social interactions while keeping the same space allowance for the two groups: INT2 lambs as described for INT1 in Experiment 1, and SPA lambs that remained isolated from the flock with their mothers but had the same increase in pen surface area as INT2 lambs. Both INT2 and SPA lambs displayed a preference for their own mothers at 12 h but INT2 lambs did so more rapidly. Our data also suggest that INT1 and INT2 lambs chose their own mothers at a distance. These results demonstrate that progressively increasing social interactions with flock members other than the mother facilitates the establishment of a preference for the mother in lambs. Increasing space allowance only also seems to have facilitating effects. This suggests that a rich socio-spatial environment from birth has beneficial effects on the development of filial bonding.