Ten ways remote sensing can contribute to conservation

In an effort to increase conservation effectiveness through the use of Earth observation technologies, a group of remote sensing scientists affiliated with government and academic institutions and conservation organizations identified 10 questions in conservation for which the potential to be answered would be greatly increased by use of remotely sensed data and analyses of those data. Our goals were to increase conservation practitioners’ use of remote sensing to support their work, increase collaboration between the conservation science and remote sensing communities, identify and develop new and innovative uses of remote sensing for advancing conservation science, provide guidance to space agencies on how future satellite missions can support conservation science, and generate support from the public and private sector in the use of remote sensing data to address the 10 conservation questions. We identified a broad initial list of questions on the basis of an email chain‐referral survey. We then used a workshop‐based iterative and collaborative approach to whittle the list down to these final questions (which represent 10 major themes in conservation): How can global Earth observation data be used to model species distributions and abundances? How can remote sensing improve the understanding of animal movements? How can remotely sensed ecosystem variables be used to understand, monitor, and predict ecosystem response and resilience to multiple stressors? How can remote sensing be used to monitor the effects of climate on ecosystems? How can near real‐time ecosystem monitoring catalyze threat reduction, governance and regulation compliance, and resource management decisions? How can remote sensing inform configuration of protected area networks at spatial extents relevant to populations of target species and ecosystem services? How can remote sensing‐derived products be used to value and monitor changes in ecosystem services? How can remote sensing be used to monitor and evaluate the effectiveness of conservation efforts? How does the expansion and intensification of agriculture and aquaculture alter ecosystems and the services they provide? How can remote sensing be used to determine the degree to which ecosystems are being disturbed or degraded and the effects of these changes on species and ecosystem functions?     

Freisetzung von Schwermetallen aus dem bodenbildenden Tonmineral Illit durch Aminosäuren

Kaolin W from Lohrheim (51% Illite, 31% Kaolinite, 18% Quarz, no Carbon) was loaded with various amounts of heavy metal ions (0.11–6.0 mmol/100g Cu, Ni, Cd) from their nitrate solutions. In the next step the release of the bound metals was tested with or without aminoacids (penicillamine and histidine) in solutions of weak acidity or alkalinity. It was found an evident influence of the aminoacids to the metal release in dependence of metalcoating, metal-aminoacid-ratio and experimental pH. Especially in alkali environment a multiplication of the copper release (to a factor of 39 (pen) or 27 (his)) was observed. An increased nickel (factor 53) and cadmium release (factor 4.5) was found with histidine. In this cases 80 to 100% of the heavy metals were removed from the clay-mineral-surface.     

The influence of size-specific indirect interactions in predator-prey systems

Nonlethal indirect interactions between predators often lead to nonadditive effects of predator number on prey survival and growth. Previous studies have focused on systems with at least two different predator species and one prey species. However, most predators undergo extreme ontological changes in phenotype such that interactions between different-sized cohorts of a predator and its prey could lead to nonadditive effects in systems with only two species. This may be important since different-sized individuals of the same species can differ more in their ecology than similar-sized individuals of different species. This study examined trait-mediated indirect effects in a two-species system including a cannibalistic predator with different-sized cohorts and its prey. I tested for these effects using larvae of two stream salamanders, Gyrinophilus porphyriticus (predator) and Eurycea cirrigera (prey), by altering the densities and combinations of predator size classes in experimental streams. Results showed that the presence of large individuals can significantly reduce the impact of density changes of smaller conspecifics on prey survival through nonlethal means. In the absence of large conspecifics, an increase in the relative frequency of small predators significantly increased predation rates, thereby reducing prey survival. However, with large conspecifics present, increasing the density of small predators did not decrease prey survival, resulting in a 14.3% lower prey mortality than predicted from the independent effects of both predator size classes. Small predators changed their microhabitat use in the presence of larger conspecifics. Prey individuals reduced activity in response to large predators but did not respond to small predators. Both predators reduced prey growth. These results demonstrate that the impact of a predator can be significantly altered by two different types of trait-mediated indirect effects in two-species systems: between different-sized cohorts and between different cohorts and prey. This study demonstrates that predictions based on simple numerical changes that assume independent effects of different size classes or ignore size structure can be strongly misleading. We need to account for the size structure within predator populations in order to predict how changes in predator abundance will affect predator-prey dynamics.     

Population ecology of the green/black turtle (<Emphasis Type="Italic">Chelonia mydas</Emphasis>) in Bahía Magdalena,Mexico

The mangrove channels of Bahía Magdalena, Mexico, are important developmental areas for juvenile green, or black turtles (Chelonia mydas), but incidental bycatch and illegal hunting threaten population persistence. We studied size distribution, condition index (CI), growth rates, and mortality of black turtles in Estero Banderitas, the largest mangrove channel in Bahía Magdalena, to supply information for the development of effective conservation strategies. A total of 213 black turtles (including 88 recaptures) were caught in entanglement nets between July 2000 and July 2003. Average yearly catch per unit of effort (CPUE, 1 unit: 100 m of net fishing for 12 h) dropped during the study from 2.19 to 0.76. About 97% of all turtles were considered juveniles, average size was 54.6 ± 9.5 cm. Turtles were significantly smaller at the head of Estero Banderitas than in the central part of the Estero and in the open bay, indicating size-based habitat segregation. Average growth rate was 1.62 cm/year and declined with increasing size. Growth was seasonal and three times higher in summer (0.28 cm/month) than in winter (0.09 cm/month), body CI was also significantly higher during the summer months. A seasonalized von Bertalanffy growth function (VBGF) was used to model growth for the size range studied (43–73 cm SCL), with the parameters: L _∞ = 101 cm SCL; K = 0.04 year⁻¹; t ₀ = 0; C = 0.4 and t _s = 0.75. Growth data indicate that black turtles may spend up to 20 years in Bahía Magdalena before they reach maturity at about 77 cm SCL. The total mortality estimate (Z) from the length converted catch curve was 0.16, corresponding to a yearly survival probability of 0.85.     

Patterns of houses and habitat loss from 1937 to 1999 in northern Wisconsin, USA.

Rural America is witnessing widespread housing development, which is to the detriment of the environment. It has been suggested to cluster houses so that their disturbance zones overlap and thus cause less habitat loss than is the case for dispersed development. Clustering houses makes intuitive sense, but few empirical studies have quantified the spatial pattern of houses in real landscapes, assessed changes in their patterns over time, and quantified the resulting habitat loss. We addressed three basic questions: (1) What are the spatial patterns of houses and how do they change over time; (2) How much habitat is lost due to houses, and how is this affected by spatial pattern of houses; and (3) What type of habitat is most affected by housing development. We mapped 27 419 houses from aerial photos for five time periods in 17 townships in northern Wisconsin and calculated the terrestrial land area remaining after buffering each house using 100- and 500-m disturbance zones. The number of houses increased by 353% between 1937 and 1999. Ripley's K test showed that houses were significantly clustered at all time periods and at all scales. Due to the clustering, the rate at which habitat was lost (176% and 55% for 100- and 500-m buffers, respectively) was substantially lower than housing growth rates, and most land area was undisturbed (95% and 61% for 100-m and 500-m buffers, respectively). Houses were strongly clustered within 100 m of lakes. Habitat loss was lowest in wetlands but reached up to 60% in deciduous forests. Our results are encouraging in that clustered development is common in northern Wisconsin, and habitat loss is thus limited. However, the concentration of development along lakeshores causes concern, because these may be critical habitats for many species. Conservation goals can only be met if policies promote clustered development and simultaneously steer development away from sensitive ecosystems.     

Screening of organic halogens and identification of chlorinated benzoic acids in carbonaceous meteorites

The occurrence of halogenated organic compounds measured as a sum parameter and the evidence of chlorinated benzoic acids in four carbonaceous meteorites (Cold Bokkeveld, Murray, Murchison and Orgueil) from four independent fall events is reported. After AOX (Adsorbable organic halogen) and EOX (Extractable organic halogen) screening to quantify organically bound halogens, chlorinated organic compounds were analyzed by gas chromatography. AOX concentrations varying from 124 to 209 microg Cl/g d.w. were observed in carbonaceous meteorites. Ion chromatographic analysis of the distribution of organically bound halogens performed on the Cold Bokkeveld meteorite revealed that chlorinated and brominated organic compounds were extractable, up to 70%, whereas only trace amounts of organofluorines could be extracted. Chlorinated benzoic acids have been identified in carbonaceous meteorite extracts. Their presence and concentrations raise the question concerning the origin of halogenated, especially chlorinated, organic compounds in primitive planetary matter.     

The structure of stereotyped calls reflects kinship and social affiliation in resident killer whales (Orcinus orca)

A few species of mammals produce group-specific vocalisations that are passed on by learning, but the function of learned vocal variation remains poorly understood. Resident killer whales live in stable matrilineal groups with repertoires of seven to 17 stereotyped call types. Some types are shared among matrilines, but their structure typically shows matriline-specific differences. Our objective was to analyse calls of nine killer whale matrilines in British Columbia to test whether call similarity primarily reflects social or genetic relationships. Recordings were made in 1985–1995 in the presence of focal matrilines that were either alone or with groups with non-overlapping repertoires. We used neural network discrimination performance to measure the similarity of call types produced by different matrilines and determined matriline association rates from 757 encounters with one or more focal matrilines. Relatedness was measured by comparing variation at 11 microsatellite loci for the oldest female in each group. Call similarity was positively correlated with association rates for two of the three call types analysed. Similarity of the N4 call type was also correlated with matriarch relatedness. No relationship between relatedness and association frequency was detected. These results show that call structure reflects relatedness and social affiliation, but not because related groups spend more time together. Instead, call structure appears to play a role in kin recognition and shapes the association behaviour of killer whale groups. Our results therefore support the hypothesis that increasing social complexity plays a role in the evolution of learned vocalisations in some mammalian species.