Nutrient flows and land use change in a rural catchment: a modelling approach

Due largely to unprecedented land-use changes in the Porijõgi River catchment (southern Estonia) losses of nutrients and organic matter have decreased significantly. During the period 1987–1997 abandoned lands increased from 1.7 to 10.5% and arable lands decreased from 41.8 to 23.9%. At the same time, the runoff of total-N, total-P, SO₄ and organic matter (after BOD₅) decreased from 25.9 to 5.1, 0.32 to 0.13, 78 to 48, and 7.4 to 3.5 kg ha^–1 yr^–1, respectively. The most significant decreases occurred in agricultural subcatchments while the changes were insignificant in the forested upper course catchment. A simple empirical model which incorporates land-use pattern, fertilization intensity, soil parameters and water discharge accurately described the variations of total-N and total-P runoff in both the whole catchment and its agricultural subcatchments (R ² varies from 0.95–0.99 for N to 0.49–0.93 for P). In small agricultural subcatchments the rate of fertilization is found the most important factor for nitrogen runoff, whereas in larger mosaic watersheds land use pattern plays the main role. Seven alternative scenarios compiled on the base of the empirical model allow to forecast potential nitrogen and phosphorus losses from the catchment. This information can be used in further landscape and regional planning of the whole region.     

Valuing ecosystem services in community-based landscape planning: introducing a wellbeing-based approach

The challenge of incorporating the concept of ecosystem services in landscape planning has been widely acknowledged, yet values of ecosystem services are not well considered in current landscape planning and environmental governance. This is particularly the case when local stakeholders are strongly involved in decision making about adapting the landscape to future demands and challenges. Engagement of stakeholders introduces a variety of interests and motives that result in diverging value interpretations. Moreover, participative planning approaches are based on learning processes, implying that the perceptions of value evolve during the planning process. Current valuation approaches are not able to support such process. Therefore we argue that there is a need for a novel view on the mechanism of integrating valuation in the different stages of community-based landscape planning, as well as for tools based on this mechanism. By revisiting the original conception of ecosystem services and redefining the value of an ecosystem service as its comparative importance to human wellbeing, we develop a conceptual framework for incorporating ecosystem service valuation that captures the full spectrum of value and value changes. We acknowledge that in the social interactions during the planning process values are redefined, negotiated and reframed in the context of the local landscape. Therefore, we propose a valuation mechanism that evolves through the phases of the cyclic planning process. We illustrate the use of this mechanism by proposing a tool that supports stakeholder groups in building a value-based vision on landscape adaptation that contributes to all wellbeing dimensions.     

Predicting grey squirrel expansion in North Italy: a spatially explicit modelling approach

There is growing concern about the spread of the North American grey squirrel (Sciurus carolinensis) in northern Italy which were introduced into Piedmont in 1948. They have since spread across the Po-plain covering an area of approximately 450 km² and continue to expand their range. In parallel to what has been observed in Britain and Ireland, grey squirrels replace the native red squirrel (S. vulgaris) and damage poplar (Populus) plantations through bark-stripping. Spatially explicit population dynamics models have been successfully used to predict the spread of grey squirrels in East Anglia, England. We extended a previous approach employing a sensitivity analysis where life history and other demographic inputs are generated using Latin Hypercube Sampling from the known ranges of each input parameter, and applied it to Italy using field data collected in Piedmont. The analysis indicated that reproductive output was the most important factor determining total population size present in Piedmont. The structure and composition of woodland habitats around the introduction site suggested that initial grey squirrel expansion would have been slow and subject to emigration rates from the available habitat blocks.A comparison of the 1996 survey results with model predictions indicated that a mean litter size of three young gave the best fit with the observed distribution and we use this to predict future grey squirrel spread. We also present a worst case scenario in which grey squirrels experience improved reproductive success due to the availability of high quality habitats beyond the Po plain. In both cases they could disperse along existing continuous woodland corridors into France between 2039–2048. The case of the grey squirrel highlights the problems of implementing conservation conventions and the resulting conflicts between wildlife management, public perception and local political support and the narrow time frame that is available to control alien species effectively before it is too late. If allowed to spread, grey squirrels have the potential of becoming a European forest pest species and are likely to replace the native red squirrel in large parts of its range.     

Linking wind erosion to ecosystem services in drylands: a landscape ecological approach

Context

Wind erosion is a widespread environmental problem in the world’s arid landscapes, which threatens the sustainability of ecosystem services in these regions.

Objectives

We investigated how wind erosion and key ecosystem services changed concurrently and what major biophysical and socioeconomic factors were responsible for these changes in a dryland area of China.

Methods

Based on remote sensing data, field measurements, and modeling, we quantified the spatiotemporal patterns of both wind erosion and four key ecosystem services (soil conservation, crop production, meat production, and carbon storage) in the Mu Us Sandy Land in northern China during 2000–2013. Linear regression was used to explore possible relationships between wind erosion and ecosystem services.

Results

From 2000 to 2013, wind erosion decreased by as much as 60% and the four ecosystem services all increased substantially. These trends were attributable to vegetation recovery due mainly to government-aided ecological restoration projects and, to a lesser degree, slightly increasing precipitation and decreasing wind speed during the second half of the study period. The maximum soil loss dropped an order of magnitude when vegetation cover increased from 10% to 30%, halved again when vegetation increased from 30 to 40%, and showed little change when vegetation increased beyond 60%.

Conclusions

Our study indicates that vegetation cover has nonlinear and threshold effects on wind erosion through constraining the maximum soil loss, which further affects dryland ecosystem services. These findings have important implications for ecological restoration and ecosystem management in dryland landscapes in China and beyond.

     

Landscape-scale patterns and drivers of novel mammal communities in a human-modified protected area

Landscape Ecology - The role of protected areas as biodiversity repositories has become increasingly important in face of increased deforestation. By adding free-living exotic mammals, removing...     

Landscape-scale characteristics of forest tornado damage in mountainous terrain

Context

Landscape patterns created by natural disturbance such as windstorms can affect forest regeneration, carbon cycling, and other ecological processes.

Objectives

We develop a method for remotely measuring tornado damage severity and describe landscape-scale patterns of tornado damage. We examine the extent and distribution of damage severity and gaps created by tornadoes, and examine how topographic variation can influence tornado damage severity.

Methods

Focusing on two April 2011 tornadoes that struck the Chattahoochee National Forest (CNF) in Georgia and the Great Smoky Mountains (GSM) in Tennessee, we used supervised classification of aerial photographs to map damage severity. We report the extent and distribution of damage severity from each track and characterize patterns of damage using FragStats. Using topographic overlays, we test hypotheses regarding how physiographic features such as valleys and ridges affect tornado damage severity.

Results

Tornado damage severity estimates were significantly correlated with ground-truth measurements. The 64-km CNF track damaged 1712 ha (>25 % severity), while the 26-km GSM track damaged 1407 ha. Tornado damage severity was extremely variable and frequency of gap sizes drastically decreased with size, with many small gaps and few very large gaps, consistent with other types of wind damage. Damage severity declined as tornadoes ascended ridges and increased as they descended ridges. This effect was more consistent on shallow slopes relative to steeper slopes.

Conclusions

This study outlines an objective methodology for remotely characterizing tornado damage severity. The results from this study fill an important gap in ecological understanding of the spatial components of the forest tornado disturbance regime.

     

Landscape-scale Edge Effect in Predation Risk in Forest-farmland Mosaics of Central Europe

Avian nest predation is known to increase with the degree of forest fragmentation. A common explanation is that farmland allows for high densities of generalist predators, and predators penetrating into the forest cause higher nest losses at forest-farmland edges than in forest interiors. In contrast to numerous patch-level studies of forest edge effects conducted earlier, we broadened the spatial extent to the landscape. We tested the hypothesis of increased predation near farmland over distances of >4 km from forest–farmland edges into forest interiors in five mountain ranges in Germany, using artificial ground nests. We considered two landscape settings: (1) Transitions between a forest matrix and a farmland matrix, and (2) farmland patches within a forest matrix. Nest losses were not significantly higher in vicinity to a farmland matrix, but proximity to a pasture within the forest matrix strongly increased predation risk. We speculate that these differences resulted from landscape geometry. Farmland patches and matrix alike are highly attractive to generalist predators, and are regularly visited by red foxes from the forest. Predators that traverse the forest and take prey along the way, will cause a concentration of predation risk towards a patch (pasture), but not towards an adjacent matrix (farming lowlands), of feeding habitat. Contrary to previous evidence that edge effects in nest predation level off after 50 m, nest fate was related to distance to pastures across the entire study extent of 4.1 km. Our results suggest that landscape context and predator mobility may greatly affect spatial predation patterns.     

Introducing urban food forestry: a multifunctional approach to increase food security and provide ecosystem services

We examine the potential role of perennial woody food-producing species (“food trees”) in cities in the context of urban sustainable development and propose a multifunctional approach that combines elements of urban agriculture, urban forestry, and agroforestry into what we call “urban food forestry” (UFF). We used four approaches at different scales to gauge the potential of UFF to enhance urban sustainability and contribute to food security in the context of urbanization and climate change. First, we identified 37 current initiatives based around urban food trees, and analyzed their activities in three categories: planting, mapping, and harvesting, finding that the majority (73 %) only performed one activity, and only 8 % performed all three. Second, we analyzed 30 urban forestry master plans, finding that only 13 % included human food security among their objectives, while 77 % included habitat for wildlife. Third, we used Burlington, Vermont as a case study to quantify the potential fruit yield of publicly accessible open space if planted with Malus domestica (the common apple) under nine different planting and yield scenarios. We found that 108 % of the daily recommended minimum intake of fruit for the entire city’s population could be met under the most ambitious planting scenario, with substantial potential to contribute to food security even under more modest scenarios. Finally, we developed a Climate–Food–Species Matrix of potential food trees appropriate for temperate urban environments as a decision-making tool. We identified a total of 70 species, 30 of which we deemed “highly suitable” for urban food forestry based on their cold hardiness, drought tolerance, and edibility. We conclude that substantial untapped potential exists for urban food forestry to contribute to urban sustainability via increased food security and landscape multifunctionality.     

Incorporating ecosystem services into ecosystem-based management to deal with complexity: a participative mental model approach

Integrating ecosystem services into ecosystem-based management (EBM) is currently one of the most relevant challenges for management. For that purpose, it is necessary to depict the relationships established between ecosystems and society considering the delivery, use and governance of ecosystem services. One effective way of doing so involves collaboration between researchers, who scientifically study the system, and managers, who have specific experience and technical knowledge. With this aim, we held two workshops in 2011 in the National Parks of Doñana and Sierra Nevada, Andalusia (Spain), with researchers and managers from the protected areas at different organizational levels: local, regional and national. Taking the participative mental model technique as an inspiration, we developed a tool that was used as a means to allow a holistic analysis of ecosystem services from an interdisciplinary and participative perspective. We found that participatory mental models, help integrating ecosystem services into EBM as it includes stakeholders’ proposals and knowledge. For the implementation of ecosystem services for management, we discuss the necessity of navigating a process that requires considerable changes, not only in using new concepts such as ecosystem services, but also in the management structures that govern the services. This process would require closer interaction between citizens, researchers and managers, and the creation of new participation spaces that include ecosystem service beneficiaries located beyond protected areas.     

Landscape-scale assessment of tree crown dieback following extreme drought and heat in a Mediterranean eucalypt forest ecosystem

Mediterranean regions are under increasing pressure from global climate changes. Many have experienced more frequent extreme weather events such as droughts and heatwaves, which have severe implications for the persistence of forest ecosystems. This study reports on a landscape-scale assessment investigating potential associated factors of crown dieback in dominant tree species following an extreme dry and hot year/summer of 2010/11 in the Northern Jarrah Forest of Western Australia. Analyses focussed on the influence of (i) geology, (ii) topography, (iii) climate, and (iv) fire history. The results showed that trees on specific soils were more likely to show canopy dieback. Generally, trees on rocky soils with low water holding capacity were found to be affected more frequently. Other explanatory factors identified that dieback occurred (i) on sites that were close to rock outcrops, (ii) in areas that received a slightly higher amount of annual rainfall compared to the surrounding landscape, (iii) on sites at high elevations and (vi) on steep slopes, and (v) in areas that were generally slightly warmer than their surroundings. These results expand our understanding of how landscape-scale factors contribute to the effects of an extreme drought and heating event in Mediterranean forest ecosystems, and give indications of where changes are likely to occur within the landscape in the future. The analogues with other Mediterranean climate regions make the results of this study transferable and a starting point for further investigations.     

New approach for using trunk growth rate and endocarp development in the irrigation scheduling of young olive orchards

Trunk diameter variation (TDV) is considered one of the most promising tools for automating the scheduling of fruit tree irrigation, and trunk growth rate (TGR) a possible indicator of TDV values. The use of TGR in commercial orchards is less common in olive trees than in other species, possibly because the influence of the environment, orchard age and the presence of developing fruit on the olive tree seasonal TGR pattern is poorly understood. In this study the trunk growth rate (TGR) seasonal progression was characterized in fully irrigated young olive trees during fruiting and non-fruiting years. In both years, at the beginning of the season, a period with an almost linear increase was found, mainly determined by temperature. In the non-fruiting year TGR remained almost constant after that initial increase, while during the fruiting year a significant decrease occurred at approximately 25 days, from values around 0.2 mm day⁻¹ to values around 0.1 mm day⁻¹. Since midday shoot water potentials were not affected, this variation was likely not produced by water stress conditions. In addition, the lack of relationship between trunk growth rate and air temperature indicated that the TGR decrease in the fruiting year was not determined either by air temperature. The period of decreasing TGR values, however, coincided with the time that the endocarp reached its maximum transverse area, a significant moment for fruit development which precedes pit hardening. These results suggest that the traditional period where regulated deficit irrigation is done, “the pit hardening”, may be indicated easier and more accurate for TGR decrease and endocarp expansion.     

山地板栗低产园增产改造技术

1998年开始对山地板栗低产园进行改造，采取嫁接良种，合理修剪，加强土壤管理，科学施肥和综合防治病虫害等措施，2001年666.7m^2产量达229kg，较改造前增产2倍多。     

The inclusion of stakeholders and cultural ecosystem services in land management trade-off decisions using an ecosystem services approach

Context

An ecosystem service approach for land-use or conservation decisions normally uses economic or biophysical assessments for valuating nature’s services. In contrast, even though ecosystem services are required for human well-being, the actual use of services by differing stakeholder groups are rarely considered in typical ecosystem service assessments, especially the more intangible, cultural ecosystem services.

Objectives

The aim of this research was to quantify different uses for 15 cultural and provisioning ecosystem service indicators across seven stakeholder groups in a watershed proposed with large hydroelectric dam development.

Methods

We used a large-scale survey to quantify use and frequency of use for ecosystem services.

Results

We demonstrate that different stakeholder groups use ecosystem services differently, both in terms of specific ecosystem service indicators, as well as for frequency of ecosystem service use. Across all stakeholder groups, specific cultural ecosystem services were consistently more important to participants when compared to provisioning ecosystem services, especially aesthetic/scenic values.

Conclusions

This work is of global importance as it highlights the importance of considering cultural ecosystem services (e.g. aesthetic/scenic, sense-of-place values) along with multiple stakeholder groups to identify the trade-offs and synergies during decision-making processes for land-use or conservation initiatives.

     

荣成市果园土壤肥力状况调查

1982年和2006年,对全市果园的土壤pH值、容重、有机质及氮磷钾含量的变化进行调查分析,提出合理施肥和改进其他管理的建议.     

京亚葡萄温室丰产高效栽培技术

葡萄果实汁多味美,酸甜爽口,营养丰富.1998～1999年进行了京亚葡萄温室栽培试验.结果表明:温室葡萄成熟期较露地早50天,平均株产2.0～2.5kg,平均667m2(1亩)产量达1 700kg.     

Characterizing wild ass pathways using a non-invasive approach: applying least-cost path modelling to guide field surveys and a model selection analysis

Movement of animals is a key process affecting population dynamics. Information on factors that affect pathway use is essential for identifying and protecting pathways, and important for maintaining connectivity among populations. We present an innovative, non-invasive, approach for predicting pathways of reintroduced Asiatic wild ass (Equus hemionus) in Israel, which is based on understanding the effects of landscape factors on pathways use. The approach includes: Predicting pathways, by employing a least cost pathway (LCP) GIS models based on several landscape factors, so as to efficiently direct a field survey and explore the wild ass’s general preferences of pathway types; Collecting empirical data by surveying the dung density of wild ass along each of the predicted pathways and using the data as an index of pathway use; Evaluating the predicted pathways against the empirical data collected, to estimate the general pathway preferences of the wild ass; and Developing and evaluating alternative generalized linear models, according to a priori hypotheses based on empirical data so as to quantify the effect of different landscape factors on pathway use. The analyses were conducted for the entire landscape, and then for two distinct landscape types, open landscape and landscape-barriers (mountain ridges), as subsets of the entire landscape. There were clear differences in the mean number of faeces counts between the LCPs, indicating that the wild ass prefers certain pathway types as a function of landscape features. We further found that the factors affecting E. hemionus pathway usage—vegetation; slopes; canyons; and 4-wheel drive routes—varied largely between the two major landscape types studied, demonstrating the importance of studying space use patterns at different landscape terrains. This information can be applicable to landscape planning measures that aim to enhance protection of the species. This approach provides a framework for studying animal space-use patterns of a variety of species, including elusive species, in a heterogeneous landscape.     

Landscape-scale effects of forest degradation on insectivorous birds and invertebrates in austral temperate forests

Context

Insectivorous birds are sensitive to forest disturbances that may limit the availability of food consisting mainly of invertebrates. However, birds and invertebrates may be differently affected by forest disturbances while invertebrates may interact with disturbances.

Objectives

We aim to determine: (i) the effects of forest degradation on invertebrates and insectivorous birds; (ii) the effect of the availability of invertebrates as a food source on birds; (iii) interactions between food availability and forest degradation.

Methods

We selected 34 1-km radius landscape units, where the abundance of birds and invertebrates was sampled in the canopy and understory. Bird density as well as the abundance and richness of invertebrates were considered as dependent variables and analysed using Generalized Linear Mixed Model and Structural Equation Models. Remote-sensing indices of forest degradation were included as predictors.

Results

Eight indices of forest degradation affected canopy and understory invertebrates differently. Unlike invertebrates, bird abundance was affected by a smaller number of degradation indices, forest amounts as well as the cover of understory and canopy. Only two forest degradation indices had a comparable effect on bird abundance and invertebrates. We found causal relationships between understory invertebrates and the abundance of understory birds (all species and the small-sized ones), but also invertebrate abundance × forest cover interactions affected the abundance of a bird species.

Conclusions

Our results indicate that birds and invertebrates respond differently to forest degradation, but also provide evidence for bottom-up control by forest degradation and suggest food limitation varies with forest amounts.