Threatened landscapes in the Mediterranean: examples from Crete

A recent study of desertification in Crete and the south Aegean has found few signs of climatic change or accelerated soil erosion. Increasing reliance on ground water presents a risk for the future. The main changes in the landscape are a great extension of the area under olives, and an increase in natural trees and bushes. More pines present a fire hazard. Burning of maquis by shepherds requires further examination. Migration, urbanisation and technological developments in agriculture in the last few decades have had a profound effect on Mediterranean landscapes. Depopulation of mountainous inland areas and small offshore islands results in a diminution of the historical and scenic value of their landscapes. This research project aims to identify and characterise landscapes in western Crete which are of special value and which are threatened by current developments; it attempts to trace changes in the last few decades, and to propose means of maintaining them in the future.     

Red Books for threatened Mediterranean landscapes as an innovative tool for holistic landscape conservation. Introduction to the western Crete Red Book case study

In view of the alarming threats to our planet Earth and its natural and cultural diversity, the IUCN World Conservation Organization must broaden the scale of its efforts from the species and ecosystem level to the landscape level. For this purpose new, more comprehensive strategies and powerfuls tools, based on holistic landscape planning and dynamic conservation management, are urgently needed. The Mediterranean Basin, presently undergoing an alarming process of biological, cultural and scenic degradation can serve as a good example for these needs. Here, as elsewhere, almost all conservation efforts have been devoted to the protection of restricted areas such as nature reserves or parks without much regard for the fate of the open landscape as a whole and the need for the conservation and restoration of its great natural and cultural assets. In order to gain greater public awareness and apprehension of these threats, to change the attitudes of politicians and decision-makers, and to provide practical guidance for holistic, sustainable and multibeneficial land use planning and management, a new tool of ‘Red Books for Threatened Landscapes’ is offered. These should present in clear non-technical terms, with ample maps and illustrations, recent, adverse biological, ecological, cultural and socio-economic changes in highly valuable and not yet irreversibly despoiled landscapes and their future threats, and suggest alternative, sustainable land use strategies with sounder conservation and restoration options. The Western Crete study, is the first Mediterranean Red Book case study, carried out by a multinational and multidisciplinary team. It will serve as an important example for a Red Book blueprint, to be prepared by the IALE-IUCN-CESP Working Group on Red Books for Threatened Landscapes.     

Applying biodiversity concepts to plantation forestry in northern Mediterranean landscapes

Biodiversity refers to the variety and variability among living organisms and the ecological complexes in which they occur. The importance of biodiversity has been conceptually well recognized in plantation forestry. Even if stress of biodiversity varies according to the forest plantation use, cautious adjustments of standard planning and cultivation techniques oriented to biodiversity can generally give significant benefits, not only in terms of plantation sustainability and stability, but also in terms of landscape enhancement and maintenance of ecotope productivity. In this perspective, basic and operational aspects of introducing biodiversity ideas into forest plantation planning, establishment and management are discussed, underlying that afforestation may represent a useful means of enhancing biodiversity within the northern Meditteranean landscapes, both on chorological and topologic scales.     

Biological diversity of Mediterranean landscapes in Israel through the development of nature reserves

The high landscape diversity of Israel is well represented by the 311 set up nature reserves. The major Mediterranean landscapes in the 119 proclaimed nature reserves in this region are: Meditterranean maquis, park forest, scrublands and grasslands, canyons and streams, wetlands and coastal landscapes. Habitat diversity, as well as diverse management regimes, result in a high biological diversity.     

Concentrations of plutonium and americium in plankton from the western Mediterranean Sea

Understanding the transfer of radionuclides through the food chain leading to man and in particular, the uptake of transuranic nuclides by plankton, is basic to assess the potential radiological risk of the consumption of marine products by man. The main sources of transuranic elements in the Mediterranean Sea in the past were global fallout and the Palomares accident, although at present smaller amounts are released from nuclear establishments in the northwestern region. Plankton from the western Mediterranean Sea was collected and analyzed for plutonium and americium in order to study their biological uptake. The microplankton fractions accounted for approximately 50% of the total plutonium contents in particulate form. At Garrucha (Palomares area), microplankton showed much higher 239,240 Pu activity, indicating the contamination with plutonium from the bottom sediments. Concentration factors were within the range of the values recommended by the International Atomic Energy Agency. Continental shelf mesoplankton was observed to efficiently concentrate transuranics. In open seawaters, concentrations were much lower. We speculate that sediments might play a role in the transfer of transuranics to mesoplankton in coastal waters, although we cannot discard that the difference in species composition may also play a role. In Palomares, both 239,240 Pu and 241Am showed activities five times higher than the mean values observed in continental shelf mesoplankton. As the plutonium isotopic ratios in the contaminated sample were similar to those found in material related to the accident, the contamination was attributed to bomb debris from the Palomares accident. Concentration factors in mesoplankton were also in relatively good agreement with the ranges recommended by IAEA. In the Palomares station the highest concentration factor was observed in the sample that showed predominance of the dynoflagellate Ceratium spp. Mean values of the enrichment factors showed, on average, discrimination rather than enrichment in the primary producer trophic chain.     

Impact of anthropogenic activities on the Densu River in Ghana

A detailed study has been carried out on the Densu River and its tributaries to identify the chemical characteristics of the water, examine the hydrological connections among the land cover types and evaluate the relative contributions of anthropogenic activities to the river's pollution. The results indicate that sites closer to the most urbanized, industrialized and agricultural areas are severely impaired. The river water was found to vary considerably in terms of chemical and physical properties. The water was slightly alkaline, brackish to fresh and of mixed Ca–Na–HCO₃ and Ca–HCO₃ types. Nutrient and organic matter were found to be the most frequent cause of pollution of the river. Pollution has reached such a proportion that it has destroyed the aquatic ecosystem in most exposed sections of the river.     

Impact of climatic fluctuations and land use change on runoff and nutrient losses in rural landscapes

Results on the influence of land use and climatic changes on nutrient losses in the Porijõgi river catchment, south Estonia, are presented. The main tendency in land use changes is a significant increase in abandoned lands (from 1.7% in 1987 to 12.5% in 1994), and a decrease in arable lands (from 41.8 to 22.5%). Significant climatic fluctuations were observed from 1951–1994. Warmer winters (increase from −7.9 to −5.8°C from 1950–1994) and a change in the precipitation pattern have influenced the mean annual water discharge. This results in more intensive material flow during colder seasons and decreased water runoff in summer. Changes in water discharge and land use are also reflected in the mean annual runoff of total inorganic nitrogen (TIN) and total-P which decreased from 15.6 to 2.7 kg N ha⁻¹ yr⁻¹ (83%) and 0.32 to 0.21 kg P ha⁻¹ yr⁻¹ (34%), respectively during this period. However, nutrient losses from the forest subcatchment (upper course) did not change significantly. In contrast, the mean annual runoff of water, organic matter (after biological oxygen demand: BOD₅), TIN, total-P and SO₄ from cultivated subcatchments showed a significant decrease.     

Impact on the water column biogeochemistry of a Mediterranean mussel and fish farm

We investigated and compared the impact of organic loads due to the biodeposition of mussel and fish farms on the water column of a coastal area of the Tyrrhenian Sea (Western Mediterranean). Physico-chemical data (including oxygen, nutrients. DOC and particulate organic matter), microbial variables (picoplankton and picophytoplankton density and biomass) and phytoplankton biomass (as chlorophyll-a) were determined on a monthly basis from March 1997 to February 1998. The results of this study indicate that both fish farm and mussel culture did not alter significantly dissolved inorganic phosphorus and chlorophyll-a values, while inorganic nitrogen concentrations were higher in mussel farm area. However, waters overlying the fish farm presented significantly higher DOC concentrations. In contrast, no significant differences were observed comparing particulate matter concentrations. The increased DOC concentrations determined a response of the heterotrophic fraction of picoplankton, while picophytoplankton, likewise phytoplankton. did not display differences among fish or mussel farms and control site. From the analysis of the different microbial components, it is possible to conclude that the impact of fish farms is evident only for the heterotrophic components. The comparative analysis of the mussel biodeposition and fish-farm impact revealed that mussel farms induced a considerably lower disturbance, apparently limited to an increased density and biomass of microbial assemblages beneath the mussel cultures.     

Impact of nitrate addition on biofilm properties and activities in rising main sewers

Anaerobic sewer biofilm is a composite of many different microbial populations, including sulfate reducing bacteria (SRB), methanogens and heterotrophic bacteria. Nitrate addition to sewers in an attempt to control hydrogen sulfide concentrations affects the behaviour of these populations, which in turn impacts on wastewater characteristics. Experiments were carried out on a laboratory reactor system simulating a rising main to determine the impact of nitrate addition on the microbial activities of anaerobic sewer biofilm. Nitrate was added to the start of the rising main during sewage pump cycles at a concentration of 30 mg-N L⁻¹ for over 5 months. While it reduced sulfide levels at the outlet of the system by 66%, nitrate was not toxic or inhibitory to SRB activity and did not affect the dominant SRB populations in the biofilm. Long-term nitrate addition in fact stimulated additional SRB activity in downstream biofilm. Nitrate addition also stimulated the activity of nitrate reducing, sulfide oxidizing bacteria that appeared to be primarily responsible for the prevention of sulfide build up in the wastewater in the presence of nitrate. A short adaptation period of three to four nitrate exposure events (approximately 10 h) was required to stimulate biological sulfide oxidation, beyond which no sulfide accumulation was observed under anoxic conditions. Nitrate addition effectively controlled methane concentrations in the wastewater. The nitrate uptake rate of the biofilm increased with repeated exposure to nitrate, which in turn increased the consumption of biodegradable COD in the wastewater. These results provide a comprehensive understanding of the impact of nitrate addition on wastewater composition and sewer biofilm microbial activities, which will facilitate optimization of nitrate dosing for effective sulfide control in rising main sewers.     

基于景观三元论的园林建筑与植物造景分析

以江南古典园林为例,基于同济大学刘滨谊教授的景观三元论：视觉景观形象,环境生态绿化,大众行为心理,对古典园林中建筑形制与植物的关系进行了深入研究,以期指导现代的景观设计。     

如何利用园林植物实现人与景观的互动

通过阐述植物景观的重要性,让人们更加重视城市景观中的植物配置,应用植物景观调研、查阅大量资料分析提炼的途径,提出了如何利用园林植物实现人与景观互动的方法,以指导景观设计师创造出符合人们需求的优美植物景观。     

Impact of different parts of unpaved forest roads on runoff and sediment yield in a Mediterranean area

Surface runoff and sediment production on unpaved forest roads in a humid Mediterranean mountainous area has been studied using a simple portable rainfall simulator at an intensity of 90 mm h^− 1. Thirty six rainfall simulations were carried out on road plots: on the roadbank (12), on the sidecast fill (12), and on the roadbed (12). On the roadbanks, the steady-state runoff coefficient was 85.9% and runoff flow appeared after 63 s on average. On the sidecast fills, the steady-state runoff coefficient was 58.6% and mean time to runoff was 48 s. Finally, on the roadbeds, the steady-state runoff coefficient was 21.5% and mean time to runoff was 41 s. The highest soil loss rate was found on the roadbanks (486.7 g m^− 2), mainly due to low plant cover, soil texture and rock fragments. The total soil erosion on the roadbanks was 3 and 18 times higher than those from the roadbeds and the sidecast fills, respectively. As a consequence, roadbanks can be considered the main source of sediments on the studied sites, but the function of unpaved forest roads as source points for runoff generation is more important.     

太行山前平原农业活动对地下水影响评价

太行山前平原农业用水是地下水消耗的主体,研究农业活动对区域地下水的影响对促进地下水安全和粮食安全具有重要意义。本文在分析太行山前平原用水特征的基础上,确定有效灌溉面积,满足作物需水的有效降水量,以及主要耗水型作物小麦、玉米和蔬菜种植面积作为反映农业活动对地下水影响的指标要素,运用投影寻踪评价模型和MapGIS技术进行影响程度的评价并进行等级划分,最终根据农业活动对地下水影响程度将太行山前平原分为影响制约区、影响较大区、影响一般区和影响较小区四种类型区。     

喷锚支护技术在深基坑工程中的应用

喷锚挂网支护作为基坑的一种支护形式,与其它支护方法相比,该方法具有经济、适用、可靠、施工便捷、变形小等显著优点,尤其在深基坑支护上优点明显,目前该施工支护技术在大型深基坑支护中被广泛应用。文章结合工程具体案例,分析喷锚网支护如何发挥作用,以及具体技术特点和实际应用效果的可行性。     

Impact of western coal mining—II. Microbiological studies

The occurrence and activity of certain groups of sulfur cycle bacteria associated with waters, sediments, and the coal bearing strata of a coal strip mine at Decker, Montana, were studied. Mining areas in northeastern Wyoming were also examined.Thiobacillus ferooxidans, one of the major contributors to acid mine drainage, was consistently detected in the mining environment. Physiological studies of T. ferrooxidans isolates indicated that these acidophilic iron and sulfur oxidizing organisms were typical of the species in their preference for low pH and ability to oxidize pyrite. Since (i) acidic conditions were not observed at Decker, (ii) the organisms did not multiply in mine water environments and (iii) no acid could be formed from coal samples inoculated with a T. ferrooxidans isolate, it was thought that their activity was limited to microzones in the coal bearing strata where they oxidized sulfuritic material. Any acid formed was quickly neutralized by mineral carbonates associated with the groundwaters and overburden.Sulfate reducing bacteria also were common in the mine waters and sediments. These organisms were particularly active in the sedimentation pond sediments as was evidenced by the rapid rate of conversion of radio-labeled sulfate to sulfide. The hydrogen sulfide produced by these organisms contributed to heavy metal precipitation in the sedimentation pond.     

Impact of dynamic airflow on human thermal response

Airflow fluctuation is an important factor affecting indoor thermal environments and human thermal response. In this study, dynamic airflows with different fluctuation characteristics were generated by a dynamic air supply terminal. The influence of three different kinds of airflows, constant airflow, simulated natural airflow and sinusoidal airflow, on thermal comfort was studied. Subjective experiments indicated that a dynamic airflow can cause a stronger cold sensation, and that air movement with 1/f fluctuations similar to natural wind is more acceptable than other dynamic airflows in warm environments. Moreover, the impact of draughts in dynamic airflows on human thermal response is different in neutral-warm (30 degrees C) and cool-neutral (26 degrees C) thermal environments. PRACTICAL IMPLICATIONS: By means of a dynamic air supply terminal it is possible to generate artificial airflows that simulate natural wind indoors. This kind of airflow with higher velocity is more comfortable and causes less draught sensation than the constant airflows supplied by conventional fans. While the cooling effect of this airflow is utilized in the built environment, the design temperature of air-conditioning system can be increased and the amount of energy consumption can be reduced dramatically.     

Effect of industrial-urbanized landscapes on underground waters

Theoretical and empiric problems of the chemical composition of subsoil waters in industrial-urbanized landscapes of the intermediate zone of the European part of the USSR are generalized. Data characteristic of the most common chemical components in subsoil waters and their changeability regularities dependent on the increase in their formation under geological-hydrogeological conditions both in depth and latitudional extention are considered. Precise dependence of chemical composition and subsoil water quality on the geomorphological situation, lythology of soil and growth of city construction was established.     

基于CIS谈石家庄城市景观设计

基于CIS城市设计理念,对石家庄城市形象进行了定位,并给出了基于CIS对石家庄城市规划设计的步骤、方法、措施,为石家庄城市规划及城市建设做了有益的尝试和探索。     

Urban landscapes on public space in the post-industrial city

The relative indeterminacy ofpublic space has led to two rather different linesof research. One pertains to the sociology ofculture, with rather general studies of a broadscope that cover lengthy historical periods and callfor an analysis of urbanity in the Western world.The other line of research includes the extremelydetailed studies of human conduct in specific urbanspatial settings. This paper takes a differentapproach: public space is described based on thenotion of urban landscapes, which are expressionsof economic, demographic and technologicaldevelopments.