Ethnobotany of Woody Species in Second-Growth, Old-Growth, and Selectively Logged Forests of Northeastern Costa Rica

Abstract: We assessed quantitatively the woody species used for timber, medicine, and other products in 10 tropical wet-forest stands with different land-use histories in the Atlantic lowlands of northeastern Costa Rica. Species were classified into 20 use categories based on regional ethnobotanical studies. Three size classes of woody vegetation were sampled in nested, contiguous plots along transects: trees (≥5 cm diameter at breast height [dbh]), saplings (>1 m high, <5 cm dbh), and seedlings (>20 cm high, <1 m high). Our study included five second-growth stands, three old-growth stands, and two selectively logged stands. Of the 459 woody species surveyed, 70% of the species and 86% of the total number of individuals had at least one use. Overall, species richness was highest for medicinal species (167 species). Absolute and relative abundance of medicinal and timber trees was significantly higher in second-growth stands than in old-growth and selectively logged stands. For 8 of the 15 use categories examined statistically, stem density showed no significant differences across forest types for any stem size class. Young, tropical, second-growth forests and selectively logged forests have high utilitarian as well as conservation value and will likely become important sources of forest products. The success of secondary forest regeneration, however, depends critically upon conservation of genetically diverse source populations in forest fragments and protected old-growth stands.     

Local Responses to Inundation and De-Farming in the Reservoir Region of the Three Gorges Project (China)

Large-scale infrastructural developments in rural areas often impose significant direct and indirect impacts on environment and people. The Three Gorges Project to dam the Yangtze River in China will create a huge reservoir, inundate farmlands and villages, and incur large-scale resettlement. The concurrent de-farming program to reforest marginal farmlands on steep slopes imposes additional stresses on local people. This study evaluates the ecological and economic adjustments in rural areas affected by both projects, and explores villagers’ knowledge, attitudes, perceptions, and expectations vis-à-vis the drastic changes. Eleven villages in Yunyang County in Sichuan Province, stratified into three zones based on topography and agriculture, were assessed by field studies, questionnaire surveys, maps, satellite imagery, and census and government reports. Multiple regressions identified predictors for 17 dependent variables. Spatial variations in the difficult terrain imposed zone-differentiated agricultural constraints, ecological impacts, and human responses. The dominant farming population—mainly young adults working as migrant laborers in cities—has adopted some nonagricultural work to supplement incomes. Expected per-capita standardized farmland (SF) exceeded threshold SF, which surpasses existing SF. Motivations to reclaim more farmlands, de-farm marginal lands, and become migrant laborers were explained by different multiple-regression predictors. Reduction in farmland stock by inundation and de-farming, aggravated by unwillingness towards nonlocal resettlement, would impose ecological pressures and stimulate demands for nonfarming incomes. Common anticipation of better future income and occupation has been subdued by unfavorable feedbacks from early relocatees. Future environmental and landscape changes are hinged upon changing human responses. Government policies could be informed by research findings to match economic, ecological, and social realities.     

Batterienrecycling: Möglichkeiten zur Erhöhung der Rücklaufquote

Separate collection and exploitation of used batteries facilates the recycling and eventual waste management of such heavy metals as mercury and cadmium. It is thereby possible to regain raw materials like zinc, manganese and iron for the raw material cycle. Although the collection and recycling of used batteries in Switzerland is financed by a prepaid disposal fee, their returning rate of almost 60% is too low for several reasons. A questionnaire survey carried out on 2000 households revealed the following frequenthy: People collecting paper, glass, aluminium, compost and tinplate, are more separate used batteries from ordinary garbage. The number of collecting points is supposed to be sufficient, but not all of them are sufficiently marked. The prepaid disposal fee (VEG) should become obligatory so that it would be possible to compensate the collecting points. It is not obvious from the results of the survey if the introduction of a deposit of batteries would raise the retourning rate. As far as advertising is concerned, only the “battery bag” sent to every household by the BESO seemed to influence the collecting behaviour in a positive way, poster advertising had only little effect. Appeals in newspapers, radio and television did not show any changement of the collecting behaviour. However, information and knowledge about batteries and their recycling do have a positive influence in the collecting behaviour of the consumers in this specific case.     

A complimentary tool in the determination of activity concentrations of naturally occurring radionuclides

The determination of activity concentrations of radionuclides requires a reliable gamma spectrometry system, which also depends on the compulsory attainment of secular equilibrium amongst the progenies of the radionuclide of interest. This is often difficult to attain and hence a helium particle induced x-ray emission technique, not requiring the compulsory attainment of secular equilibrium, was used to determine the actual concentrations of the elemental content of tailings from the high background radiation tin mining area, Jos, Nigeria. The activity concentrations of the radionuclides of ⁴⁰K, ²³²Th and ²³⁸U were also calculated based on their elemental analyses, providing reliable information about the heads of uranium (²³⁸U) and thorium (²³²Th) series on the study area.     

Optimizing line intercept sampling and estimation for feral swine damage levels in ecologically sensitive wetland plant communities

Ecological sampling can be labor intensive, and logistically impractical in certain environments. We optimize line intercept sampling and compare estimation methods for assessing feral swine damage within fragile wetland ecosystems in Florida. Sensitive wetland sites, and the swine damage within them, were mapped using GPS technology. Evenly spaced parallel transect lines were simulated across a digital map of each site. The length of each transect and total swine damage under each transect were measured and percent swine damage within each site was estimated by two methods. The total length method (TLM) combined all transects as a single long transect, dividing the sum of all damage lengths across all transects by the combined length of all transect lines. The equal weight method (EWM) calculated the damage proportion for each transect line and averaged these proportions across all transects. Estimation was evaluated using transect spacings of 1, 3, 5, 10, 15, and 20 m. Based on relative root mean squared error and relative bias measures, the TLM produced higher quality estimates than EWM at all transect spacings. Estimation quality decreased as transect spacing increased, especially for TLM. Estimation quality also increased as the true proportion of swine damage increased. Diminishing improvements in estimation quality as transect spacings decreased suggested 5 m as an optimal tradeoff between estimation quality and labor. An inter-transect spacing of 5 m with TLM estimation appeared an optimal starting point when designing a plan for estimating swine damage, with practical, logistical, economic considerations determining final design details.     

Effect of liquid municipal biosolid application method on tile and ground water quality

This study examined bacteria and nutrient quality in tile drainage and shallow ground water resulting from a fall land application of liquid municipal biosolids (LMB), at field application rates of 93,500 L ha(-1), to silt-clay loam agricultural field plots using two different land application approaches. The land application methods were a one-pass AerWay SSD approach (A), and surface spreading plus subsequent incorporation (SS). For both treatments, it took between 3 and 39 min for LMB to reach tile drains after land application. The A treatment significantly (p < 0.1) reduced application-induced LMB contamination of tile drains relative to the SS treatment, as shown by mass loads of total Kjeldahl N (TKN), NH(4)-N, Total P (TP), PO(4)-P, E. coli., and Clostridium perfringens. E. coli contamination resulting from application occurred to at least 2.0-m depth in ground water, but was more notable in ground water immediately beneath tile depth (1.2 m). Treatment ground water concentrations of selected nutrients and bacteria for the study period ( approximately 46 d) at 1.2-m depth were significantly higher in the treatment plots, relative to control plots. The TKN and TP ground water concentrations at 1.2-m depth were significantly (p < 0.1) higher for the SS treatment, relative to the A treatment, but there were no significant (p > 0.1) treatment differences for the bacteria. For the macroporous field conditions observed, pre-tillage by equipment such as the AerWay SSD, will reduce LMB-induced tile and shallow ground water contamination compared to surface spreading over non-tilled soil, followed by incorporation.     

Economic,equitable, and affordable adaptations to protect coastal settlements against storm surge inundation

The distribution of risk of coastal inundation, and the potential benefits of adapting to protect against inundation, vary greatly both within and between coastal communities. This diversity is a result of physical factors, such as the risk of storm surge, sea level rise projections, and the topography of the landscape, as well as socio-economic factors, such as the level of development, and the capacity within the community to adapt. Despite this strong local variation, various communities share common characteristics that constrain or enable different adaptation options in different situations. Understanding these drivers is likely to be important in engaging coastal communities in the discussion around adaptation and may provide new insights into which adaptation options are suitable for each of our at-risk coastal communities. We performed a property-level analysis of 6 suburb-sized case studies distributed along the coast of Queensland, Australia. We assessed the potential economic costs of inundation events now and in the future under sea level rise projections, and the potential avoided costs following adaptation to protect against inundation. We went beyond this to estimate the distribution of risk in each community and compared the potential costs of adaptation with the capacity of the community to pay for their implementation. We used these insights to propose a typology of coastal communities based on their exposure to total inundation risk, the distribution of that risk within the community, and their capacity to adapt.     

Adapting the adaptive cycle: Hypotheses on the development of ecosystem properties and services

Ecosystems are dynamic complexes. These dynamics can be described by different ecophysiological parameters and systems theoretical concepts like succession, thermodynamics, information/network theory, resilience, adaptability and the orientor concept. In this paper, different indicators and concepts are linked to Holling's adaptive cycle metaphor in order to derive hypotheses on potential system trajectories. The hypotheses focus on an exemplary temperate forest ecosystem experiencing the adaptive cycle's four phases of exploitation, conservation, collapse and reorganization after an initializing fire event. The different properties are correlated to the number of total system connections and show varying trajectories. Additionally, the provision of selected forest ecosystem services during the different phases is hypothesized and compared to three other land use types.     

The role of the queen mandibular gland pheromone in honeybees (<Emphasis Type="Italic">Apis mellifera</Emphasis>): honest signal or suppressive agent?

Queen pheromones interfere with worker reproduction in social insects. However, there is still an unresolved question as to whether this pheromone acts as an “honest” signal for workers, giving a reliable indication of the queen’s reproductive value, or as a suppressive agent, inhibiting worker reproduction independent of the queen’s reproductive capacity. In honeybees (Apis mellifera), the queen’s mandibular gland secretion, a mix of fatty acids and some aromatic compounds, is crucial for regulating the reproductive division of labor in the colony inhibiting ovary development in workers. We quantified the mandibular gland secretions of virgin, drone-laying, and naturally mated queens using gas chromatography to test whether the queens’ mating, ovary activation, or the reproductive value for workers correlated with the composition of the secretion. Although the absolute amounts of the “queen substance” 9-oxo-2(E)-decenoic acid (9-ODA) were similar among the three groups, the proportions of 9-ODA decreased with increasing reproductive quality. Furthermore, the ratios of queen to worker compounds were similar in all three treatment groups, irrespective of the reproductive capacity. A multivariate analysis including all six compounds could not separate drone-laying queens from naturally mated ones, both with active ovaries but only the latter ensuring colony survival. We suggest that the mandibular gland pheromones are unlikely to function as reliable indicators of queen reproductive value and rather operate as an agent to suppress worker reproduction. This does not exclude the possibility that other “honest” pheromone signals exist in the honeybee colony, but these would have to arise from other semiochemicals, which could be produced by both the queen and the brood.     

Production and Characterization of Bioplastics Obtained by Injection Moulding of Various Protein Systems

Bioplastic materials from renewable polymers, like proteins, constitute a highly interesting field for important industrial applications such as packaging, agriculture, etc., in which thermo-mechanical techniques are increasingly being used. This study assesses bioplastic materials produced by injection from blends previously prepared in a batch mixer using various protein concentrates and isolates. A mixing time of 5 min has been selected in order to ensure correct homogenous blends. A comparison between different protein-based specimens was performed by dynamic mechanical thermal analysis, tensile strength, water uptake and transmittance tests. The comparison reveals that the protein nature and the percentage of plasticizer lead to bioplastics with different properties and, consequently, different applications. Protein concentrates and isolates, wastes and surpluses from the food industry, may be useful for producing bioplastics with suitable mechanical properties and processability, as well as biodegradability, by means of suitable mixing and injection moulding conditions.