Showing papers in "Landscape and Ecological Engineering in 2020"

Combined allelopathy of Canada goldenrod and horseweed on the seed germination and seedling growth performance of lettuce

Abstract: The allelopathy on the seed germination and seedling growth performance (SgeSgrPe) of indigenous plant species (IPS) are considered as the main fact of the successful colonization of multiple invaders The co-invasion of two invaders is common in some natural ecosystems Thus, it is essential to assess the combined allelopathy of two invaders on SgeSgrPe of IPS to address the mechanisms driving the successful colonization This study objects to assess the independent and combined allelopathy of two notorious invaders Canada goldenrod (Solidago canadensis L) and horseweed [Conyza canadensis (L) Cronq] (using leaf extracts) on SgeSgrPe of the IPS lettuce (Lactuca sativa L) via the incubation experiment in Petri dishes Specifically, the independent and combined allelopathy of Canada goldenrod and horseweed leaf extracts on most of the seedling growth parameters of lettuce enhanced with the growing concentration of leaf extracts The independent Canada goldenrod leaf extracts motivate greater allelopathy on most of SgeSgrPe parameters of lettuce compared to the independent horseweed leaf extracts at the same concentration Consequently, the allelopathy on IPS may act a more prominent role in the successful colonization posed by Canada goldenrod than horseweed supposedly The combined Canada goldenrod and horseweed leaf extracts trigger significantly higher allelopathy on most of seedling growth parameters of lettuce than the independent horseweed leaf extracts but pose significantly lower allelopathy than the independent Canada goldenrod leaf extracts at the same concentration Thus, an antagonistic effect of allelopathy could occur after the co-invasions of the two invaders in some ecosystems, especially on the seedling growth of IPS This implies that the allelopathy of Canada goldenrod and horseweed on the seedling growth of IPS may play a more prominent role in their single invasion process (particularly for Canada goldenrod) than in their co-invasion

The influence of urban spatial pattern on land surface temperature for different functional zones

Abstract: Urban functional zone (UFZ) comprises the basic unit of urban planning, with various production activities. Understanding the landscape heterogeneity in UFZs may be a way to mitigate urban heat island (UHI). The region within fifth ring road in Beijing is selected as the study area. Six common UFZ types were selected to understand the effects of three types of factors (surface biophysical parameters, building form, and landscape metrics) on land surface temperature (LST). A one-way analysis of variance and geographical detector were used to express spatial heterogeneity and key influencing factors of LST in UFZ, respectively. The results indicate the following: (1) the UFZ types, in order from highest to lowest LST, are industrial, commercial, public service, government, high-density residential, and recreational zones. The LST of industrial and recreational zones are significantly different from other zones, but other four types of UFZ exhibited similar thermal conditions. (2) The key influencing factors of LST in UFZs differ. Surface biophysical parameters have a significant effect on all UFZs. Building form in areas of high building height and density, such as commercial and high-density residential zones, should be the focus of UHI mitigation, whereas optimizing land cover composition and spatial configuration in other UFZs is more likely to alleviate LST. In addition, the LST is determined not only by the UFZ type and internal structure, but also by the complexity and diversity. Identifying UHI mitigation sensitivity metrics within UFZ will help improve the thermal environment of urban areas and provide strategies for resisting UHI.

Ecosystem services potential for climate change resilience in peri-urban areas in Sub-Saharan Africa

Abstract: Ecosystem services provide considerable development opportunities, including incorporating land use planning and enhancing climate change resilience in peri-urban communities. However, the application of this concept in planning and enhancing climate change resilience is negligible in Sub-Saharan Africa (SSA). This article reviews state-of-the-art research on the potential contribution of peri-urban ecosystem services to climate change resilience in SSA and identifies research gaps for further work. This study was conducted through systematic review of articles from the Web of Science. The literature shows limited knowledge on peri-urban ecosystem services research globally and SSA in particular. The gaps in this knowledge stem from inadequate conceptualization and lack of understanding about how such knowledge can be translated into policy, planning and management and, hence, realizing development goals. In nutshell, the potential for climate change resilience of well-managed peri-urban ecosystem services includes reducing the physical exposure of peri-urban areas to floods and droughts and minimizing climate change risks through increased socio-economic resilience to hazard impacts and provision of the carbon sequestration function. However, specific peri-urban studies describing ecosystem service types and how they can be synchronized into mainstream urban planning and climate change resilience strategies are lacking in most SSA urban regions/landscapes. Therefore, case studies need to be conducted to contextualize and downscale the concept in peri-urban areas and to determine how the concept can be synchronized into broad urban planning and strategies for enhancing resilience to climate change in vulnerable urban and peri-urban communities.

Improving the provision of ecosystem services from urban forest by integrating the species’ potential environmental functions in tree selecting process

Abstract: Due to the fact that urban environments and population demands are evolving rapidly and species selection is inevitable, it is possible to gain substantial environmental benefit by implementing more effective urban tree planting programs, especially with the aim of increasing the upcoming provision of multiple ecosystem services (ES) through proper species selection. In this paper, we used a new approach to improve the potential of urban trees in optimizing more desirable environmental benefits. This was done by selecting the most appropriate tree species among a vast range of species based on their potential environmental function (both services and disservices) in Tabriz city, Iran. Also, three main planting scenarios (divided to six sub-scenarios) were developed so as to understand the long-term effectiveness of introducing the selected tree species in improving the environmental benefits (both urban forest structure and ES) in comparison with planting the existing tree species. The results indicate that regardless of the quantity of planting, the benefits of introducing the selected trees will be more than planting the existing species. Moreover, as the amount of the annual planting of the recommended species increases, so does the improvement in the projected tree characteristics and ES. This approach creates more opportunities which enable urban forest managers and policymakers to understand the importance of selecting the proper urban tree species when looking for a nature-based solution to promote the wellbeing of the urban population, to create more livable and ecologically sustainable cities and to mitigate urban environmental problems.

Applying a socio-ecological green network framework to Xi’an City, China

Abstract: Green–blue space loss and fragmentation are particularly acute in Chinese cities due to rapid urbanization, large ring-road system and the following city compartments. Therefore, connecting urban green–blue spaces has been recently advocated by central government. This paper revised and applied the recently developed urban green network approach to the case of Xi’an city, China, a city which has been rarely studied before from this perspective. The focus was on connecting fragments of urban green–blue spaces to compact green–blue networks, integrating both social and ecological functions into a fully functioning entity. Landscape metric analysis was added to identify that the main city outside the city core should be a planning priority zone. The Eurasian tree sparrow (Passer montanus), Asiatic toad (Bufo gargarizans) and humans at leisure were selected as three focal species to meet the emerged socio-ecological benefits. Sociotope and biotope maps were drawn up to identify patches with high human recreation and wildlife shelter values and providing crucial network structures. Least-cost-path model was used for identifying potential linkages between patches. This model was based on network structures and cost surface, which measures the theoretical energy cost of travelling between landscape elements. By integrating the potential paths for the selected organisms with density analysis, the updated framework generated three improvement maps for species indicators, and 10 network corridors for establishing green–blue networks at city scale. At neighbourhood scale, one site with habitat and linkage examples illustrated specific measures that could be taken in local practice.

Integrated framework of system dynamics and meta-heuristic for multi-objective land use planning problem

Abstract: Land use optimization as a resource allocation problem can be defined as the process of assigning different land uses to a region. Sustainable development also involves the exploitation of environmental resources, investment orientation, technology development, and industrial changes in a coordinated form. This paper studies the multi-objective sustainable land use planning problem and proposes an integrated framework, including simulation, forecasting, and optimization approaches for this problem. Land use optimization, a multifaceted process, requires complex decisions, including selection of land uses, forecasting land use allocation percentage, and assigning locations to land uses. The land use allocation percentage in the selected horizons is simulated and predicted by designing a System Dynamics (SD) model based on socio-economic variables. Furthermore, land use assignment is accomplished with a multi-objective integer programming model that is solved using augmented e-constraint and non-dominated sorting genetic algorithm II (NSGA-II) methods. According to the results of the SD model, land use changes depend on population growth rate and labor productivity variables. Among the possible scenarios, a scenario focusing more on sustainable planning is chosen and the forecasting results of this scenario are used for optimal land use allocation. The computational results show that the augmented e-constraint method cannot solve this problem even for medium sizes. The NSGA-II method not only solves the problem at large sizes over a reasonable time, but also generates good-quality solutions. NSGA-II showed better performance in metrics, including number of non-dominated Pareto solutions (NNPS), mean ideal distance (MID), and dispersion metric (DM). Integrated framework is implemented to allocate four types of land uses consisting of residential, commercial, industrial, and agricultural to a given region with 900 cells.

High uncertainties detected in the wetlands distribution of the Qinghai–Tibet Plateau based on multisource data

Abstract: Twenty wetland-related data products (including remote sensing datasets, compilation datasets and model simulation datasets) were collected to evaluate the characteristics (area and distribution) of the wetlands in the Qinghai–Tibet Plateau (QTP) during four stages (1980s, 1990s, 2000s, and 2010s). We conducted a statistical analysis of the wetland areas from different datasets and compared the pixel consistency regarding wetland spatial distribution. The results showed that high uncertainty exists in the wetland area and low consistency exists in the distribution among the different datasets. The wetland area in the QTP ranged from 1.5 × 104 to 121.16 × 104 km2. In the remote sensing datasets, the wetland area in the QTP ranged from 3.25 × 104 to 11.28 × 104 km2, the calculated area was between 1.50 × 104 and 72.21 × 104 km2 in the compilation datasets, and the area simulated from model datasets was between 3.81 × 104 and 121.16 × 104 km2. For the total wetland area in the QTP, the uncertainty in the measured datasets was lower than that in the model simulation datasets. However, for the distribution of wetlands, the measured datasets were more inconsistent than the model datasets. In the measured datasets, as the pixel consistency increased, the corresponding probability throughout the area decreased. The probability of achieving 75% consistency was less than 2%, and was 0.61%, 0.35%, 1%, and 1.43% in the four stages, respectively. In the model products, the probability of achieving 75% consistency was 40.39%. Our study will enrich the global wetland database and contribute to the establishment of a plateau wetland information system, which will be significant for the protection and management of wetlands.

Experimental study of scouring downstream of coastal vegetation in an inundating tsunami current

Abstract: Local scour by inundating tsunami currents on the land side of coastal forests can greatly decrease the tsunami mitigation advantage of the forest by producing driftwood. The purpose of this study was to analyze the scour profiles inside and behind a forest model (FM) due to the flow passing through it, and to compare the scour phenomenon around fixed and moveable bed cases within the FM. Two series of flume experiments were conducted by changing initial water depths (water depth without FM in the flume, ho = 3 cm to 7 cm), densities of FM (dense G/d = 0.25, intermediate G/d = 1.09, and sparse G/d = 2.13, where G = clear spacing between each cylinder in a cross-stream direction, d = diameter of a cylinder) and vegetation thicknesses (dn) of 180, 380, and 580 No.cm. In series 1 and 2, experiments were performed with a fixed bed inside FM for the three vegetation densities and for moveable bed case only for the intermediate density, respectively. Downstream scour profiles behind FM, backwater rise, and water surface gradient inside FM were investigated. For the fixed bed case, minimum scour was measured in the intermediate FM case for the three densities of 180, 380, and 580 No.cm. In the fixed bed inside FM, the location of maximum scouring moved away from the downstream end of FM while in cases of a moveable bed inside FM, the location of maximum scour moved towards the downstream end inside FM. Scour inside coastal forest damages the trees; therefore, it is recommended to stabilize the bed inside the forest by planting grasses, etc., if there is no constraint on the light environment inside the forest and the space behind the forest where local scour occurs.

Changes in land cover and ecological stress in Borneo based on remote sensing and an ecological footprint method

Abstract: Changes in land cover and ecological stressors are known to reflect the influences of human activities on regional environments and are also indicators of sustainable development. In this research, Borneo was selected as the study area. The data were sourced from Landsat TM image data obtained in 1990, 2000 and 2010, SRTM DEM data, and DMSP/OLS night-time satellite data, along with socioeconomic information, including regional population, biological resource consumption and energy consumption data. The vegetation brightness index (VBI) and the filtered normalized difference built-up index (FNDBI) are proposed, and the overall classification accuracy reached 87% when combined with decision tree classification and visual interpretation methods. Based on the traditional ecological footprint method, a dynamic calculation method for the production factor is proposed. The ecological footprint, ecological carrying capacity, and ecological deficit/surplus of Borneo in 1990, 2000, and 2010 were then calculated, and a method for creating the corresponding grid-based spatial distribution map was proposed. The effects of human activities on land cover and ecological stress in Borneo from 1990 to 2010 were analyzed in this study. The results showed that the tropical rainforests of Borneo decreased by 13% over two decades and dramatically changed to shrublands, plantations, and arable land areas. The ecological pressure increased from the central mountains to the coastal plains, and ecological deficits appeared in the coastal zones with altitudes less than 150 m in the West Kalimantan, South Kalimantan, and Sabah regions, which indicated a trend of gradual expansion. Urban construction, plantations, logging, mining, forest fires, and other human activities have interfered with natural systems, and this has led to major pressures being placed on regional sustainable development and ecological security, as well as influencing the ecological stability of other global regions.

Microhabitat characteristics affecting the occurrence and diversity of queen hornets (genus Vespa) in an urban green area

Abstract: Urban parks and green areas are increasing globally. However, when hornets (genus Vespa) in particular among wild organisms adapt to and settle in urban green spaces, they are likely to come into conflict with humans. In this study in Cheonan city, South Korea, between April and June 2017, we used hornet traps to capture queen hornets that were awakening from hibernation, and identified the characteristics of these queen hornets. We selected three green types of urban areas, namely a natural-type neighborhood park, a children’s park, and a remnant forest. We analyzed the simple regression between captured queen hornets and time over an eight-week period, as well as the relationship between captured queen hornets and microhabitat variables (including Normalized Difference Vegetation Index, canopy openness, elevation, land cover rate, and herbaceous plant cover rate), and green type. Over time, there was a significant increase in the number of Vespa ducalis and Vepsa analis that were late in awakening from hibernation. The number of captured queen hornets was significantly different in urban parks compared with in the remnant forest. However, V. ducalis was as frequently captured in the natural neighborhood park as were other queen hornet species. Some queen hornet species were significantly positively correlated with elevation (Vespa crabro, Vespa mandarinia, V. ducalis), herbaceous plant cover rate (all species of queen hornets), broad-leaved forest (all species of queen hornets), and artificially barren ground (all species of queen hornets) of microhabitat. Different species were affected differently by the microhabitat variables tested. Consequently, we recommend that when urban green spaces are created, design criteria for complex urban parks should aim at ensuring suitability for use by local residents, and for hornet conservation.

Flood mitigation function of rain gardens for management of urban storm runoff in Japan

Abstract: Urban waterlogging stems from coverage with impervious surfaces and increasing rainfall intensity from climate change and variability, meaning that storm water cannot readily infiltrate the ground and excessive surface runoff leads to urban flooding. To reduce related environmental and safety risks, rainfall and groundwater level research was carried out in Kyoto Prefecture with two rain gardens (RG1 and RG2) to investigate flood mitigation functions using a tank model. During the 134 days of monitoring from July 14, 2017, to November 25, 2017, RG1 had seven overflow events with an average runoff control ratio of 63.94%, and RG2 had one event with a ratio of 95.97%. The RG1 tank model (two stages) showed that initial storage for the first and second depths was 6.912 × 10−11 and 0 mm, respectively. The heights of the discharge holes were 20.857 and 0.784 mm for the first stage and 0.659 mm for the second stage, and the discharge hole coefficients were 0.529 and 0.002 for the first stage and 0.004 for the second stage. The results showed that RG1 had penetration hole coefficients of 0.138 (first stage) and 0.254 (second stage), with a water balance error of 0.017 (< 0.02) and a Nash–Sutcliffe efficiency coefficient of 0.922, indicating better reliability and quality than RG2 with the one-stage tank model. Peak flow simulation for mitigation showed that RG1 had a high overflow control ratio (mitigation time 2 h for instant rainfall of 100 mm/h), and can therefore be considered appropriate for other urban areas of Japan.

Nature-oriented park use of satoyama ecosystems can enhance biodiversity conservation in urbanized landscapes

Abstract: Satoyama is one of the semi-natural ecosystems in Japan. Traditional agricultural practices in satoyama provide preferable habitats for many species, thus, enhancing biodiversity. However, many satoyama ecosystems have been altered by agricultural intensification and rapid urbanization. Meanwhile, ageing and shrinking population has led to the abandonment of remaining satoyama ecosystems, resulting in their potential degradation. We argue that counteracting the abandonment of satoyama is particularly essential in urbanized landscapes because conserving its biodiversity would have a payoff for urban communities. We focused on nature-oriented park use of satoyama ecosystems, utilizing their original scenery, topography, water features, and vegetation. To evaluate the potential of nature-oriented park use for biodiversity conservation, we examined the differences in diversity and species composition of vascular plants and butterflies among three land-use types (agricultural-use, park-use, and abandoned sites) of satoyama ecosystems. Diversity of native plants and butterflies did not significantly differ between agricultural-use and park-use sites and that of native plants was significantly lower at abandoned sites than at agricultural-use sites. Although species composition of native plants at agricultural-use sites and park-use sites significantly differ, that of native butterflies did not. The efficacy of park use for biodiversity conservation, thus, depended on the taxa. Nonetheless, for striking a balance between the difficulty in maintaining agricultural use and accelerating satoyama abandonment, our study highlights the utility of park use as an alternative usage, contributing to biodiversity conservation. Balancing the wise use of satoyama in urbanized landscapes is a fundamental step toward the conservation of its biodiversity and human–nature interactions.

Inland forest as a trapping function against tsunami-borne large broken or washed out trees

Abstract: After the 2011 Great East Japan tsunami, field observations have shown the possibility of an inland forest trapping tsunami-borne large driftwood (TLD). This research was conducted to understand the driftwood trapping capability by a forest patch downstream of a shoreline, considering a model scale driftwood with attention to the crown and roots of a tree. The results demonstrated that there are four types that driftwood gets trapped by an inland forest, with each trapping type exhibiting a different force on the trapping tree. A trapping type where the driftwood got trapped at the front face of an inland forest model (IFM) in a cross-stream position by one or more trunk(s) (Type FC) exhibited high force on the trunk, because of the high cross-sectional area of the driftwood against the flow. However, when the upstream trees’ (potential to being TLD) trunk length was small, the occurrence of this trapping type decreased. The results showed that the trunk length to tree height ratio of 0.18 had a trapping occurrence of 33%, while trunk length to tree height ratio of 0.06 had a trapping occurrence of 16%. The driftwood condition, in this case, was driftwood with roots. This study further demonstrated the behaviour of driftwood trapping by an inland forest and proposed a further improvement to tsunami mitigation, by elucidating its ability to trap tsunami-generated large driftwood as a function of trunk diameter at breast height.

Landscape and local correlates with two green tree-frogs, Rhacophorus (Amphibia: Rhacophoridae) in different habitats, central Japan

Abstract: Changes in land-use and local factors have strong influences on amphibian distributions. However, the effects of both combined factors on assemblages are still unclear. The green tree-frogs, Rhacophorus, are sensitive to differences in landscape fragmentation. Herein, two species of Rhacophorus schlegelii and Rhacophorus arboreus have been surveyed, along the ecological gradient ranging from paddy-dominated plains to forest-dominated mountains (located in Toyota, Okazaki, and Shinshiro, central Japan). The effects of landscape and local factors on the existence of the above frogs were investigated using generalized linear models (GLMs); the Akaike Information Criteria (AIC) were used for model selection. The lowest AIC for R. schlegelii and R. arboreus were obtained at a 250-m-radius and 500-m-radius buffers, respectively. Habitat selections of each species showed distinct results in the paddy-field vs. ponds group. Nevertheless, both species exhibited a high abundance with increasing elevation and forest cover. At the local level, R. schlegelii displayed positive relationships with the presence of trees and the proportion of embankment vegetation. Our findings demonstrate that each species responded to various landscape scale and spatial composition, habitat, and species-dependent achievements of appropriate management actions to improve restoration practices are required.

Channel changes following human activity exclusion in the riparian areas of Bonita Creek, Arizona, USA

Abstract: Riparian areas provide many ecosystems services to humans that have been utilized for thousands of years and are the main reason why these areas are degraded. Their importance for maintaining biodiversity and stream channel health is even more important in semi-arid and arid region, such as the south-western United States. A common practice to protect riparian areas and streams in the region is the exclusion of human activities with a prime example the Gila Box Riparian National Conservation Area. In this study, we examine if the exclusion of human activities has benefited the Bonita Creek that flows through this conservation area. Cross sections at five locations along Bonita Creek were taken in 1994 and 2013. Based on the comparison of the thalweg depth, the width-depth ratio, the channel erosion/deposition and the floodplain erosion/deposition the stream channel of the two surveys, Bonita Creek appears, in general, to be benefiting from the current exclusion of human activities. Still recovery rates are not very fast indicating landscape and ecosystem-based approaches should be adopted for more effective and sustainable conservation of the area.

Effects of soil fertility and flooding regime on the growth of Ambrosia trifida

Abstract: Understanding the effects of abiotic environmental factors on invasive plants species traits is of importance for practical prevention. To examine the effects of soil fertility and flooding regime on the growth of Ambrosia trifida L., a mesocosm experiment was conducted for 18 weeks. Two levels of soil fertility (high and low) and three types of flooding regime (non-flooded, flooded, and periodically flooded) were prepared. Shoot height and dry weight of each plant were measured. We found both individual and interactive effects of soil fertility and flooding regime on the overall growth performance of A. trifida (p < 0.05). The highest shoot height (154.7 ± 4.4 cm) and total dry weight (TDW, 13.0 ± 1.4 g) were obtained under high fertility and non-flooded condition. Height and weight were relatively low under flooding conditions (flooded and periodically flooded). In particular, shoot height (102.3 ± 3.2 cm) and TDW (3.2 ± 0.3 g) were the lowest under low fertility and periodically flooded condition. On the other hand, the ratio of above- to below-ground dry weight was relatively high under flooded conditions, showing the adaptive phenotypic plasticity. Adventitious root formation and more biomass allocation to shoots were a flooding-adaptive mechanism of A. trifida, well developed under high fertility condition. We suggest maintaining appropriate water regime and avoiding eutrophication in wetlands would be necessary to prevent A. trifida from invading. These findings will contribute to the conservation of biodiversity in wetlands by effective management of A. trifida.

Efficacy of soil moisture conditions on the formation of ectomycorrhizal colonization and 137Cs absorption

Abstract: Oak represents one of the most adaptable and resilient trees on earth and is widely distributed in multiple environments ranging from wet to dry. Japanese oak forests of Fukushima and the northern Kanto area were contaminated with radiocesium (137Cs) by Fukusima Dai-ichi nuclear Power Plant accident. 137Cs trapped at the surface soil has a deleterious effect on forest ecosystem and poses further threat to humans when it enters the food chain. The uptake of 137Cs and other essential nutrients such as nitrogen (N), phosphorus (P) and potassium (K) by plants with the aid of ectomycorrhizal fungi is affected by soil water content. The objective of this study was to evaluate the colonization rate of ectomycorrhiza (CRE) and its impact on nutrients and 137Cs uptake pattern by oak (Quercus serrata Thunb.) seedlings at different soil water content levels under greenhouse condition. The result shows that the growth of Q. serrata seedlings increased with increasing soil water content. In addition, the highest CRE was observed in the low water content (LW) and was significantly different from the high water content treatment (HW). The LW treatment showed the highest N and P concentration in leaves and roots although no statistical differences were observed compared to the other treatments. Treatments with 137Cs-amended litter showed increased 137Cs concentration in the leaves of plants and its leaf per root ratio increased with decreasing soil water content. The results of the present study also suggest enhanced 137Cs absorption and translocation into Q. serrata seedlings is with the aid of ectomycorrhizal fungus except for the seedlings in HW.

Effects of weed abundance and frequency of hand weeding on the establishment of transplanted Imperata cylindrica

Abstract: Imperata cylindrica is an important component of grasslands in several Asian countries. Its vigorous rhizome elongation enables the plant to quickly cover bare ground, making it a candidate for revegetation projects. In these projects, initial and subsequent management practices often differ. Initial management strategies are important for encouraging rapid cover by the target species. We tested the effects of initial hand weeding on I. cylindrica cover and weed growth over 2 years. Two types of soil (A and B) were scattered on a recently constructed river embankment at a depth of 10 cm. Both soils A and B are nutrient-poor and high (> 7.0) pH. Plots were hand-weeded once or twice a year (W1 and W2 treatments, respectively), or mowed but not weeded (M treatment) with four replications. Plug plants of I. cylindrica were introduced. I. cylindrica became dominant in soil A with the W2 treatment, with 50% cover in year 2. Conversely, I. cylindrica failed to establish in soil B regardless of treatment, due to dominance of the weed Sorghum halepense. Soil B included creeping rhizomes of S. halepense, and vigorous growth from rhizomes is likely a major reason for its predominance. S. halepense seedlings germinated in both soils, but were successfully eradicated when weeded at less than 1 month of age. Thus, for successful revegetation, land managers should use soil that does not contain creeping rhizomes of S. halepense. If rhizomes are not present, hand weeding twice a year for 2 years is sufficient for establishment of I. cylindrica.

Fuel characteristics and fire behavior in mixed deciduous forest areas with different fire frequencies in Doi Suthep-Pui National Park, Northern Thailand

Abstract: Fires are commonly used as part of the livelihood of local people in Thailand. However, population growth is causing serious problems with agricultural expansion, forest encroachment, and illegal settlement in protected areas. Human activities are causing fires in deciduous forests increasingly frequently. Understanding the fuel characteristics and fire behavior in mixed deciduous forest areas with different fire frequencies in Doi Suthep-Pui National Park will help in developing a suitable fire management plan for this area. Twenty quadrats, each 1 × 1 m, were used to collect data regarding fuel characteristics, and 50 × 50 m quadrats were used to study fire behavior in low and high fire-frequency areas. The fuel-load data were collected every month for a period of 1 year. The results indicated that in the two fire-frequency areas, the main fuel component in this forest type was litter (leaves). Fire consumed approximately 60–70% of the total fuel loads, and fuel recovery to the original level was predicted to take around 2 years. All the fire behavior features in the LFA and the HFA showed similar characteristics, and the fire type in both areas was defined as surface fire with low intensity, which usually occurs in deciduous forests of Thailand. The heat from the fire only affected the surface soil layer and did not cause any problems in deeper layers.

A multifunctional alternative lawn where warm-season grass and cold-season flowers coexist

Abstract: Lawns provide green infrastructure and ecosystem services for anthropized areas. They have a strong impact on the environment in terms of inputs (water and fertilizers) and maintenance. The use of warm-season grasses, such as Cynodon dactylon (L.) Pers., provides a cost-effective and sustainable lawn in the dry summers of the Mediterranean. In winter, Bermudagrass is dormant and brown, which instead of being a problem could be an opportunity for biodiversity through the coexistence of flowering species. This study assesses the possibility of growing autumn-to-spring-flowering bulbs and forbs with Bermudagrass, to provide ecosystem services in urban areas. Eight geophytes and 18 forbs were incorporated into a mature turf of hybrid Bermudagrass, Cynodon dactylon × C. transvaalensis cv. “Tifway”. At the same time, a commercial flowering mix was sown in the same conditions. Two different soil preparations, scalping and turf flaming, and two different nitrogen doses, 50 and 150 kg ha−1, were carried out before sowing and transplanting. The flowering plants were counted. All the bulbs and six of the 18 forbs were able to grow and flower in the first and second years. The commercial mix was in full bloom from April until the cutting time for the hybrid Bermudagrass, at the end of May. Adding the flowering species did not affect the healthy growth of the warm-season grass. The fertilization dose had no effect, while turf flaming led to a wider spread of Bellis perennis L. and Crocus spp. Several flower-visiting insects were observed in the spring.

How to manage degraded monoculture plantations in South China: a perspective from reciprocal litter transplant experiment

Abstract: Litter decomposition, an important component of nutrient cycling, is often one of the limiting factors for the development of monoculture tree plantations for restoration, and how to improve the litter decomposition rate remains as a major challenge. To help resolve this issue, we developed a mixed-litter transplantation approach to improve the litter decomposition and nutrient cycling in Schima superba, Cunninghamia lanceolata, Eucalyptus urophylla, and Acacia mangium monoculture plantations in China. The monospecific leaf litters of the four species were collected and their possible two-, three- and four-species combinations were transplanted between plantations. We examined the influences of home/away field, litter species richness, and litter composition on litter decomposition during 24 months treatment. A significant effect of litter composition on litter decomposition (Duration × Composition effect) was detected in E. urophylla plantation. The influence of litter richness on litter decomposition was significant in A. mangium plantation (Duration × Richness effect). The litter of C. lanceolata and A. mangium had a distinct home-field advantage, while the litter of S. superba had a distinct away-field advantage in decomposition. We observed a positive relationship between richness and litter decomposition in C. lanceolate plantation. The effect of Duration × Species Interaction on litter decomposition, was significant in E. urophylla plantation, indicating a non-additive effect. Litter decomposition in E. urophylla plantation could be explained by idiosyncratic model, and the rivet model may be appropriate to illustrate the litter decomposition in A. mangium plantation. Finally, since the litter decomposition in degraded A. mangium plantations had a distinct home-field advantage and was significantly affected by litter richness, transplanting mixed litters of neighboring plantations may be beneficial to improve its litter decomposition rate. Transplanting of S. superba litters due to the distinct home-field advantage to neighboring plantations such as E. urophylla plantation whose litter decomposition is significantly affected by litter composition, may be an effective management method for improving litters decomposition.

Novel method for detection probability and estimating population size of mountain frog, Rana macrocnemis (Boulenger, 1885) at the end of its distribution range

Abstract: Local amphibian populations at the edge of a species range are possibly of greater conservation concern than any other amphibians group. They experience greater demographic fluctuation than populations at the core of the range. We detected the most suitable distribution range of R. macrocnemis by maximum entropy (MaxEnt) method at the end of the southeastern edge of natural distribution range to find out which environmental variables have a significant role in determining the distribution pattern of this species in marginal populations. According to the map constructed, three important variables had a high contribution to species presence as land cover (63.4%), annual precipitation (27%), and precipitation of coldest quarter of the year (5.4%) variables. Then, we described new methods for estimating detection probability for terrestrial frogs, specifically R. macrocnemis. Finally, we estimated the population size of mountain frogs by calculated detection probability. Our repeated capture–re-capture (RCR) results suggest that the estimated detection probability for R. macrocnemis is: $$\widehat{p} = 0.052$$. Thus, the total average number of R. macrocnemis obtained from the 17 habitat sites is 982.5 adults (range: 708–1211 adults). In conclusion, the population estimates by detection probability index are generally much higher than densities reported for the Mountain frog populations than visual encounter estimation about 50.5 adults (range: 37–63 adults).

Correction to: Rainwater storage/infiltration function of rain gardens for management of urban storm runoff in Japan

Abstract: In the original publication of the article, Figure 1 was published incorrectly. The correct figure is given below.

Overpasses intended for human use can be crossed by middle and large-size mammals

Abstract: Road overpasses cost more than underpasses and can be built for most terrestrial mammals to resolve and/or minimize effects from habitat fragmentation. Many overpasses intended for human activity might also allow wildlife passage. Using digital infrared cameras from 2015 to 2016 in Hokkaido, Japan, we evaluated such use in three overpasses, where two were designed for humans and one for wildlife. Nine mammal species were detected at the three overpasses. Three middle-sized mammals—raccoons (Procyon lotor), red foxes (Vulpes vulpes), and raccoon dogs (Nyctereutes procyonoides)—and a large mammal species, the sika deer (Cervus nippon), frequently used all of the overpasses. Our results showed that the overpass designed for wildlife was richer in species than the two overpasses for humans. However, results also showed that there were no significant differences in use among four animal species in the three overpasses. We propose the construction of small overpasses without plants to conserve habitat reconnection of middle-sized to large mammals. Arboreal species’ habitats need structural change with additional of plants.

Spatial variation and distribution of soil micronutrients relative to macronutrients in Mt. Wakakusa Grassland (central-western Japan)

Abstract: To provide spatial information on soil resources for sustainable land management in the Mt. Wakakusa Grassland of central-western Japan, we investigated the spatial variation and distribution of selected micronutrients, i.e., Mehlich 3 extractable Fe, Mn, Cu, and Zn (referred as M3-Fe, M3-Mn, M3-Cu, and M3-Zn, respectively), in surface soils (0–5 cm in depth) of the grassland. All micronutrients showed intermediate variability, with coefficients of variation ranging from 26.9 to 48.9%. The M3-Fe (144.0 ± 32.9 mg kg−1) and M3-Mn (204.8 ± 91.3 mg kg−1) contents were relatively high compared with the optimal level exhibited by M3-Cu (1.8 ± 0.5 mg kg−1) and the low level given by M3-Zn (7.8 ± 2.2 mg kg−1). The availability of these micronutrients, except for M3-Zn, showed more significant correlations with the soil mineral phase than with the soil pH and organic matter. Variogram analysis reveals a moderately weak spatial dependency [nugget-to-sill (N/S) ratio = 0.67] for the M3-Zn, while the other micronutrients (M3-Fe, M3-Mn, and M3-Cu) exhibit moderately strong to strong spatial dependencies (N/S ratio = 0.21–0.50). Interpolation maps created in this study demonstrate locations with toxic levels of M3-Fe and M3-Mn and those deficient in M3-Mn and M3-Cu in the study site. Based on these results, a site-specific soil management scheme is recommended in the Mt. Wakakusa Grassland.

Effects of road ditches on the vegetation composition in a saline environment

Abstract: The construction of transportation corridors (such as roads) frequently disturbs and alters the natural disturbance regimes of ecosystems in many areas worldwide. In this study, by comparing the species richness, diversity, composition and soil among four ecotypes (non-road disturbance areas, road systems without ditches, road systems with large and small ditches), we tested the hypothesis that the presence of road ditches could facilitate the preservation of species and increase species richness in the Yellow River Delta, China. Both positive and negative effects of road ditches on the plant community were detected. The species richness in road systems (> 14) was significantly greater than that in the non-road disturbance areas (6). In the road systems without ditches, the refuges (relatively low soil salinity: 1.12 ± 0.15 mg/g) for non-halophytes were limited to road verges (0 m from a road verge). In the road systems that included a ditch, however, the refuge area expanded from road verges to 30 m from the verges. The width and structure affected ditch function. Both large ditches and small ditches effectively reduced the salinity of the soil, but the influence mechanisms differed, resulting in differences in the distribution of species diversity. The proportion of non-halophytes was significantly greater (37%) in the road systems with large ditches than in the road systems with small ditches (45.0%). In addition, the proper structure of large ditches with slopes increased the species diversity (the species richness was 26); in contrast, some structures of small ditches reduced the species diversity (the species richness was 14). The results of our study suggest that large ditches (width > 5 m) can be constructed 10 m from road verges to increase local species richness. Moreover, it is necessary to create buffer zones alongside roads (30 m from road verge), which can prevent the movement of invasive species into internal natural areas.

Hotspots of stream tadpole diversity in forest and agricultural landscapes in Ranomafana, Madagascar

Abstract: Logging and human-induced conversion of natural forests into agricultural areas are major drivers of biodiversity loss in the tropics. Anuran larvae can be highly diverse, can reach high biomass and can play important roles in tropical streams; yet, compared to the adult frog communities, relatively little is known about how larval communities respond to disturbance. Information on larvae is highly relevant for amphibian conservation because larvae represent direct evidence of breeding and thus provide a good indicator of species persistence in disturbed habitats. We studied tadpole assemblages in Ranomafana, southeastern part of Madagascar, in streams in a disturbed forest (previously logged forest), at “forest edge” (streams embedded in matrix nearby forest blocks), and compared these to communities in a primary forest. We sampled tadpoles at the microhabitat level (“pools” and “riffles”) in 9 streams. We recorded 27 species with a maximum of 17 species/stream recorded at edge. The three habitats harbored different assemblages, but, as could be expected, more similarities existed among forest habitats than between forest and non-forest habitats. The most and the least diverse communities were recorded at edge and in the disturbed forest, respectively. Assemblages were dominated by one generalist species, and changes in communities were mostly driven by changes in forest specialists, which either decreased in disturbed forest or were replaced by edge specialists outside forest. Although species richness varied, relative abundances were maintained among habitats, suggesting potential compensatory mechanisms in tadpole biomass. Community structure changed at the microhabitat level: pool environments usually harbored relatively higher species richness and abundance than riffles. Our study highlights the relevance of edge habitats for maintaining amphibian diversity and the pronounced negative effects of past logging activities on tadpole communities. Given the diverse roles of tadpoles in streams, changes in community structure potentially affect critical stream ecosystem processes. The study has strong implications for designing buffer zones around protected areas.

Establishing the ecological planning principles from empirical studies in agricultural environments of Taiwan

Abstract: Studies have suggested that the heterogeneity and arrangement of landscape structures are influential to the faunal biodiversity of environments. How does the landscape structure in agricultural landscape arrangements improve the functions of the natural ecosystem? Previous research has uncovered a great amount of information on the relationships between landscape structure and wildlife; however, for landscape designers and planners, such information is site-specific and has limited utilization. Hence, this study aimed to organize and categorize the relationships between environments and biodiversity and transfer this information into design principles in agricultural landscapes. This study attempted to integrate aspects of previous research into a systematic framework. The current study searched literature between 2007 and 2016 from the following journals: Landscape Ecology, Landscape and Urban Planning, and Journal of Applied Ecology. In all, this study collected 58 empirical studies of agricultural environments similar to that of Taiwan and revealed the valuable relationship between wildlife and agricultural environments. The outcomes reviewed from the literature were categorized by semi-natural elements and divided into six sub-categories: forests, hedgerows, grasslands, flowers, water, and heterogeneity of the natural landscape. The landscape attributes that were frequently discussed included patch number, patch area, connectivity, species richness, edge area, distance from semi-natural elements, and complexity. The landscape attributes formed by these elements were organized into a table as a checklist for designers’ convenience. The checklist will help landscape planners and designers to create agricultural landscapes with integral ecosystems.