Changes in forest landscape due to agricultural activities and their influence on natural ecosystems: the eastern Galician mountains

Land use and landscape changes, which have much effect on local biodiversity, are driven primarily by socioeconomic forces. Understanding these forces is important for preservation of current biodiversity. In this study, we clarified the socioeconomic forces that have brought about changes in the forest landscape around the Ogawa Forest Reserve in the southern Abukuma Mountains, Japan, by interviewing local residents and reviewing local historical documents. Furthermore, we reconstructed past forest landscapes and quantified the changes that have occurred from the beginning of the twentieth century until the present by use of old land-use maps and past aerial photographs. The use of forest resources has dramatically changed during the past hundred years, and it can be divided into three periods corresponding to the level of economic development. The main landscape has changed significantly from one mainly composed of expansive grasslands and broad-leaved forests into a mosaic of fragmented secondary forests and coniferous plantations. These landscape changes reflect shifts in both the use of forest resources by local residents and the management of the national forests. Clarifying temporal–spatial landscape changes by understanding the historical relationship between humans and the landscape provides useful information for optimizing conservation and management planning.

Most studies on tropical forest dynamics focus on the processes of deforestation and forest degradation and its associated ecological impacts; comparatively little attention is given to the emergence of forest transitions. This review gives an overview of forest transitions in the tropics as involving a structural reversal from a decreasing to expanding forest area as well as related changes in forest quality and forest landscape. After introducing the concept of forest transition it first summarizes the changing forest area in tropical countries. It then discusses how the identification of a forest transition greatly depends on how forests are defined. Three types of forests with contrasting forest composition are distinguished, i.e. natural forests, modified forests and transformed forests, and forest transitions are characterized as involving either forest conversion or forest restoration. Next, forest transitions are related to changes in forested landscapes and described as involving either forest extension at a retracting agricultural frontier or incorporation of forests in forested mosaic landscapes. These processes are driven by either macro-scale socio-ecological feedbacks or socio-economic changes or by location-specific development of rural forests as part of farming intensification. This paper concludes that forest transitions do not just involve a return of natural forests and/or extension of forest plantations on forest lands, but also a multidimensional co-evolution in social and ecological conditions involving an increasing incorporation of socialized forests in forested landscapes.

Integrated geographical environment factors explaining forest landscape changes in Luoning County in the middle reaches of the Yiluo River watershed, China

In the past few decades, forest policies have caused changes in forest landscape and community lifescape in the study area of Walanae Forest Management Unit (KPH Walanae), South Sulawesi Province. This research aims to analyze forest policy dynamics and their impacts on landscape and lifescape dynamics. We quantify landscape dynamics using land use and land cover change and landscape metrics in interpreting remote sensing results of four data sets obtained in 1990, 2000, 2009, and 2016. Furthermore, we investigate lifescape dynamics using qualitative/quantitative description. We found a rapid land use change in forest landscapes within the past 26 years. A significant change showed that, in 1990–2000, the primary forest that changed into the secondary forest and shrubs has changed into dry land agriculture mix shrubs. The decreased area of the forest brought an increase in economic income for people on one side and large disturbances and forest fragmentation on the other. Various forest policies influenced the forest composition and cover but were insufficiently successful in protecting the natural forest. Results showed that several forest policies that considerably impact the landscape and lifescape conditions include forest land designation, industrial forest plantation, and restoration activities. The policies on establishing KPH and social forest program have not shown the maximum result on the landscape and lifescape improvements and, therefore, must be supported.

Forest landscapes at the southern boreal forest transition zone are likely to undergo great alterations due to projected changes in regional climate. We projected changes in forest landscapes resulting from four climate scenarios (baseline, RCP 2.6, RCP 4.5 and RCP 8.5), by simulating changes in tree growth and disturbances at the southern edge of Canada’s boreal zone. Projections were performed for four regions located on an east–west gradient using a forest landscape model (LANDIS-II) parameterized using a forest patch model (PICUS). Climate-induced changes in the competitiveness of dominant tree species due to changes in potential growth, and substantial intensification of the fire regime, appear likely to combine in driving major changes in boreal forest landscapes. Resulting cumulative impacts on forest ecosystems would be manifold but key changes would include (i) a strong decrease in the biomass of the dominant boreal species, especially mid- to late-successional conifers; (ii) increases in abundance of some temperate species able to colonize disturbed areas in a warmer climate; (iii) increases in the proportions of pioneer and fire-adapted species in these landscapes and (iv) an overall decrease in productivity and total biomass. The greatest changes would occur under the RCP 8.5 radiative forcing scenario, but some impacts can be expected even with RCP 2.6. Western boreal forests, i.e., those bordering the prairies, are the most vulnerable because of a lack of species adapted to warmer climates and major increases in areas burned. Conservation and forest management planning within the southern boreal transition zone should consider both disturbance- and climate-induced changes in forest communities.

Although global change can reshape ecosystems by triggering cascading effects on food webs, indirect interactions remain largely overlooked. Climate‐ and land‐use‐induced changes in landscape cause shifts in vegetation composition, which affect entire food webs. We used simulations of forest dynamics and movements of interacting species, parameterized by empirical observations, to predict the outcomes of global change on a large‐mammal food web in the boreal forest. We demonstrate that climate‐ and land‐use‐induced changes in forest landscapes exacerbate asymmetrical apparent competition between moose and threatened caribou populations through wolf predation. Although increased prey mortalities came from both behavioral and numerical responses, indirect effects from numerical responses had an overwhelming effect. The increase in caribou mortalities was exacerbated by the cumulating effects of land use over the short term and climate change impacts over the long term, with higher impact of land use. Indirect trophic interactions will be key to understanding community dynamics under global change.

Changes in forest landscapes have been connected with human activity for centuries and can be considered one of the main driving forces of change from a global perspective. The spatial distribution of forests changes along with the geopolitical situation, demographic changes, intensification of agriculture, urbanization, or changes in land use policy. However, due to the limited availability of historical data, the driving forces of changes in forest landscapes are most often considered in relation to recent decades, without taking long-term analyses into account. The aim of this paper is to determine the level and types of landscape changes and make preliminary study on natural and socio-economic factors on changes in forest landscapes within the protected area, Ślęża Landscape Park, and its buffer zone using long-term analyses covering a period of 140 years (1883–2013). A comparison of historical and current maps and demographic data related to three consecutive periods of time as well as natural and location factors by using the ArcGIS software allows the selected driving forces of forest landscape transformations to be analyzed. We took into account natural factors such as the elevation, slope, and exposure of the hillside and socio-economic drivers like population changes, distances to centers of municipalities, main roads, and built-up areas.

The effects of anthropogenic edges on leaf-litter and shrub arthropods were examined in both agriculture and forestry-dominated landscapes in central Saskatchewan, Canada. Microclimate, vegetation, and shrub and leaf-litter arthropods were sampled at south-facing forest edges and interiors of three sites within each landscape. Forest edges in the agricultural landscape were older and had vegetation structures that differed from those in the forestry landscape. This resulted in a sharper contrast in microclimate (temperature and humidity) between edge and interior in forests abutting agriculture than in stands abutting recent clearcuts. Arthropods from the leaf-litter and shrub-layer samples exhibited different responses to edges. In both landscapes, total shrub-arthropod abundance was not significantly affected by edges, while total leaf-litter arthropod abundance was lower at edges than in forest interiors. This reduced abundance of leaf-litter arthropods could negatively affect birds and other insectivorous vertebrates or could have been caused by greater vertebrate predation there. Forest edges in agriculture and forestry landscapes represent relative extremes in edge maturity, demonstrating that age of edges cannot completely mitigate edge effects on microclimate and abundance of arthropods. We discuss the implications of our findings for influences of forest fragmentation and landscape change on forest birds.

Mapping forest disturbance and recovery for ecological security improvement on the Qinghai-Tibet Plateau: A case study from Three Parallel Rivers Region

Scale dependence of pollinator community turnover and tritrophic interactions in changing landscapes

城市扩张对北京市城乡结合部自然和农业景观的影响——以昌平区三镇为例

Natural habitats on private lands are potentially important components of national biodiversity conservation strategies, yet they are being rapidly lost to development. Conservation easements and other means of protecting these habitats have expanded in use and will be most effective if they target private lands of highest biodiversity value and risk of loss. We developed a Biodiversity Conservation Priority Index (BCPI) based on ecological value and risk of habitat loss for remaining areas of natural vegetation cover (NVC) in the northwestern United States and addressed two questions: (1) Which remaining NVC on private lands is the highest priority for biodiversity conservation based on ecological value and risk of development? And (2) are conservation easements in NVC placed preferentially in locations of high biodiversity conservation priority? Drawing on the concept of ecological integrity, we integrated five metrics of ecological structure, function, and composition to quantify ecological value of NVC. These included net primary productivity, species richness, ecosystem type representation, imperiled species range rarity, and connectivity among "Greater Wildland Ecosystems." Risk of habitat loss was derived from analysis of biophysical and sociodemographic predictors of NVC loss. Ecological value and risk of loss were combined into the BCPI. We then analyzed spatial patterns of BCPI to identify the NVC highest in biodiversity conservation priority and examined the relationship between BCPI and conservation easement status. We found that BCPI varied spatially across the study area and was highest in western and southern portions of the study area. High BCPI was associated with suburban and rural development, roads, urban proximity, valley bottom landforms, and low intensity of current development. Existing conservation easements were distributed more towards lower BCPI values than unprotected NVC at both the study area and region scales. The BCPI can be used to better inform land use decision making at local, regional, and potentially national scales in order to better achieve biodiversity goals.

One of the most pressing issues facing the global conservation community is how to distribute limited resources between regions identified as priorities for biodiversity conservation. Approaches such as biodiversity hotspots, endemic bird areas and ecoregions are used by international organizations to prioritize conservation efforts globally. Although identifying priority regions is an important first step in solving this problem, it does not indicate how limited resources should be allocated between regions. Here we formulate how to allocate optimally conservation resources between regions identified as priorities for conservation--the 'conservation resource allocation problem'. Stochastic dynamic programming is used to find the optimal schedule of resource allocation for small problems but is intractable for large problems owing to the "curse of dimensionality". We identify two easy-to-use and easy-to-interpret heuristics that closely approximate the optimal solution. We also show the importance of both correctly formulating the problem and using information on how investment returns change through time. Our conservation resource allocation approach can be applied at any spatial scale. We demonstrate the approach with an example of optimal resource allocation among five priority regions in Wallacea and Sundaland, the transition zone between Asia and Australasia.

During the last decade the conservation of biodiversity in agricultural landscapes has been greatly emphasized. Intensification of agricultural production and practices, as well as land abandonment, have been considered as major threats (Solbrig, 1991), by making drastic changes in landscape structure and composition. The agricultural landscape is a shifting mosaic of crops, pastures, fallow lands and woody areas. Landscape elements exhibit their own disturbance regime, which depends on the practices used by farmers and thus interact with insects at several spatio-temporal scales. Changes at regional and long-term scales are the most documented and the most predictive (Baker, 1989; Rackham, 1986; Odum and Turner, 1990; Meeus, 1995; Crumley and Marquardt, 1987). A recent trend in western Europe is a decrease of the area covered by non-cultivated elements such as hedgerows, woodlots, heathlands, within intensive agricultural landscapes (Agger and Brandt, 1988; Bunce and Hallam, 1993; Burel and Baudry, 1990; Morant et al., 1995). In the mean time large tracks of farmland are abandoned. Thus the contrast between different regions increases. The changes within rural landscapes result in an increase in fragmentation of many elements and affect insect populations by reducing available habitats or seasonal refuges for many species. At a finer scale, farmers make decisions on crop succession in their farming system and on management practices for field boundaries and non-productive areas; this creates a changing landscape mosaic. Changes in agricultural landscapes can only be predicted through the knowledge of how farmers will change the land use pattern under different circumstances. Two levels must be considered: 1) changes in the type of production (e.g. from dairy production to cereals) and 2) changes in the techniques of production (e.g. feeding dairy cows with hay or maize silage). If, at a broad regional scale, relationships between the type of farming systems and landscape can be established, it becomes very fuzzy at the landscape scale, relating to, the scales of individual and population dispersal. Deffontaines et al. (1995) provide examples of two farms, in the Pays d’Auge, where the most productive one has more grassland and less annual forage crops. In all cases, the within farm land use diversity is striking, it results from both physical and spatial constraints and the requirements of the system of production (e.g. winter/summer forage). Many factors, out of the agricultural sector, also affect land use and landscape patterns, as in multi-job farms (Laurent et al., 1994). Trajectories of households as well as changes within farm systems are barely related at the individual farm scale. The major consequence from a landscape ecological point of view is that landscape changes cannot be derived from current landscape patterns (Burel and Baudry, 1990). More specifically, abandonment or dereliction of grassland is a stochastic process at the landscape scale, although deterministic at the farm scale.

The study of forest landscape change requires an understanding of the complex interactions of both spatial and temporal factors. Traditionally, forest gap models have been used to simulate change on small and independent plots. While gap models are useful in examining forest ecological dynamics across temporal scales, large, spatial processes, such as seed dispersal, cannot be realistically simulated across large landscapes. To simulate seed dispersal, spatially explicit landscape models that track individual species distribution are needed. We used such a model, LANDIS, to illustrate the implications of seed dispersal for simulating forest landscape change. On an artificial open landscape with a uniform environment, circular-shaped tree species establishment patterns resulted from the simulations, with areas near seed sources more densely covered than areas further from seed sources. Because LANDIS simulates at 10-y time steps, this pattern reflects an integration of various possible dispersal shapes and establishment that are caused by the annual variations in climate and other environmental variables. On real landscapes, these patterns driven only by species dispersal radii are obscured by other factors, such as species competition, disturbance, and landscape structure. To further demonstrate the effects of seed dispersal, we chose a fairly disturbed and fragmented forest landscape (approximately 500,000 ha) in northern Wisconsin. We compared the simulation results of a map with tree species (seed source locations) realistically parameterized (the real scenario) against a randomly parameterized species map (the random scenario). Differences in the initial seed source distribution lead to different simulation results of species abundance with species abundance starting at identical levels under the two scenarios. This is particularly true for the first half of the model run (0-250 y). Under the random scenario, infrequently occurring and shade tolerant species tend to be overestimated, while midabundant and midshade tolerant species tend to be underestimated. The over- and underestimation of species abundance diminish when examining longterm (500 y) landscape dynamics, because stochastic factors, such as fire, tend to make the landscapes under both scenarios converge. However, differences in spatial patterns, and especially species age-cohort distributions, can persist under the two scenarios for several hundred years.