Soil mesofauna and herbaceous vegetation patterns in an agroforestry landscape

Since the 1950s, the rapid depletion of natural capital due to human activities has led to a growing global demand for ecological and socioeconomic sustainability, driving the development of agroforestry. Although agroforestry ecosystems can maintain sustainable land resources and maximize land productivity, their quality continues to fluctuate. Moreover, there is no clear review of studies addressing the impact of the evolution of agroforestry landscape patterns on their ecosystems, and to fill this gap, we conducted an inclusive review. A total of 163 publications related to agroforestry ecosystem quality and landscape patterns (ELA) that met a set of inclusion criteria were obtained through the Scopus database using the literature review method of searching, appraisal, and synthesis report. The objectives were to summarize the research progress on ELA, reveal the dynamic coupling mechanism between landscape pattern evolution and ecosystem quality, explore the role of landscape pattern optimization in ecological processes and services in agroforestry, and suggest future research and policy directions. Although the understanding of landscape patterns and ecological processes has been deepened, there are limitations in the study of scales, habitats, and other aspects. It is emphasized that understanding the interaction between agroforestry and other landscape elements in spatiotemporal organization is a prerequisite for promoting sustainable benefits, and that the challenges of spatiotemporal dynamics are integrated to scientifically optimize agroforestry landscape patterns. Finally, it is necessary to gain revelations based on the coupling relationship of ELA, through scientific management of agroforestry landscapes, in order to sustainably consolidate the effectiveness of karst rocky desertification (KRD) control and to enhance human welfare.

Power transmission and transformation projects can cause certain changes to vegetation and landscape pattern, as they run through all kinds of landscapes. But Vegetation and Landscape Pattern assessment on its impact is weak in past studies, most of which focus only on theoretic summaries as well as qualitative assessments. Taking the 500kv Transmission and Transformation of Dagang-Chongzhou as example, this paper adopts landscape ecological method to assess and forecast the changes to vegetation and landscape pattern. Using the remote sensing and geographical information technology, the landscape of 500kv transmission and transformation of Dagang-Chongzhou were classified and changes in the landscape before and after the construction were analyzed. By research method of the comparative sample investigations, the indexes of plant species diversity and stability were investigated and analyzed. The study shows that if the project is put in practice, little changes will occur with respect to diversity, homogeneity of the regional vegetation and landscape pattern, and little influence will cause on primary regional vegetation and landscape pattern.

The application of local measures of spatial autocorrelation for describing pattern in north Australian landscapes

Local and landscape factors determine functional bird diversity in Indonesian cacao agroforestry

Introduction Both fine scale patterns of vegetation and coarser scale landscape patterns affect bird community composition, but the relative importance of these two sets of patterns tends to be context dependent, varying by location and taxonomic group. Here, we explore the relative roles of landscape pattern and stand structure and composition in defining bird communities in 44 remnant oak stands in the Willamette Valley, Oregon. We focused on: (1) whether bird communities are influenced more by landscape (matrix and patch) patterns or stand composition and structure, and (2) in what contexts each of these spatial scales are more important. Specifically, we focused on how different groups of bird species (functional groups, synanthropic and non-synanthropic species, and individual species) were differentially influenced by landscape and more local patterns.

Human activities and environmental changes have influenced the changes in landscape patterns, which in turn profoundly impact the variation in net primary productivity (NPP) of vegetation. Understanding the relationship between landscape patterns and NPP is of significant importance for maintaining ecosystem stability and improving the ecological environment. In this study, six land use types in the arid and semi-arid regions of Northwest China were selected, and five landscape pattern indices at the landscape level and four landscape pattern indices at the class level were used. Pearson correlation and multiple linear regression models were employed to analyze the relationship between landscape indices and NPP at a 100 km × 100 km grid scale. The results indicate that there are varying degrees of correlation between landscape pattern indices and NPP from 2001 to 2020, with different levels of variation over the 20-year period. The correlation between indices and NPP is higher at the class level than at the landscape level, and the increase in landscape abundance and fragmentation promotes an increase in NPP. At the landscape level, three landscape indices, namely NP (Number of Patches), PR (Patch Richness), and SHDI (Shannon’s Diversity Index), explain 45.4% of the variation in NPP. At the class level, NP, TE (Total Edge Length), and IJI (Dispersion and Juxtaposition Index) are the main influencing factors for NPP in cropland, forestland, and grassland. Therefore, in ecological governance, it is necessary to consider landscape pattern changes appropriately to maintain ecosystem stability.

Ecological research provides ample evidence that topography can exert a significant influence on the processes shaping broad-scale landscape vegetation patterns. Studies that ignore this influence run the risk of misinterpreting observations and making inappropriate recommendations to the management community. Unfortunately, the standard methods for landscape pattern analysis are not designed to include topography as a pattern-shaping factor. In this paper, we present a set of techniques designed to incorporate the topographic mosaic into analyses of landscape pattern and dynamics. This toolbox includes adjustments to ‘classic’ landscape indices that account for non-uniform landscape topography, indices that capture associations and directionality in vegetation pattern due to topographic structure, and the application of statistical models to describe relationships between topographic characteristics and vegetation pattern. To illustrate these methods, we draw on examples from our own analysis of landscape pattern dynamics in logged and unlogged forest landscapes in southwestern British Columbia. These examples also serve to illustrate the importance of considering topography in both research and management applications.

Riparian vegetation plays a vital role in inhibiting soil and water loss, but few studies have quantified the relationships between vegetation spatial pattern and the hydraulic characteristics of upslope runoff. This study investigated how hydraulic characteristics (e.g., runoff coefficient, flow regime, flow resistance, and flow shear stress of overland flow) responded to differences in vegetation cover (15% and 30%), slope gradient (5°, 10°, 15°, and 20°), and vegetation pattern in the riparian zone along the lower Yellow River, China, based on landscape pattern analysis and a runoff scouring experiment with flow rates of 9 and 15 L/min and an experimental plot size of 1 m × 3 m. We found that runoff generation on shallow slopes was moderated by increasing vegetation cover, but that this moderating effect decreased on steeper slopes. The regime of overland flow switched from laminar and subcritical on the 5° slope (Fr = 0.56–0.87) to laminar and critical on the 10°, 15°, and 20° slopes (Fr = 1.02–2.18). Flow resistance increased with vegetation cover and flow rate and decreased with slope gradients, and it was larger on shallow slopes with high vegetation cover. Flow shear stress had a range of 1.42–3.55 N m−2, and it increased with increasing slope gradient, vegetation cover, and flow rate. The hydraulic characteristics of upslope runoff, especially flow resistance, were significantly related to vegetation pattern at both the landscape and class levels. Flow resistance was negatively related to patch density, and positively related to perimeter–area fractal dimension and connectance index. The influencing mechanism of landscape patterns on soil erosion processes is dependent on the landscape scale, since the relationships between flow resistance and some landscape pattern indices (aggregation index, effective mesh size, and splitting index) were opposite at the landscape level compared to the class level. We conclude that fragmented vegetation distributions reduce flow resistance, and that riparian vegetation could be managed to inhibit slope erosion by increasing flow resistance.

In fragile karst watershed, landscape pattern mainly affects evapotranspiration, interception, surface runoff, soil water infiltration and groundwater formation through spatiotemporal variation of land use, vegetation pattern, and then influences the discharge and sediment transport. A new Vegetation-Topographic factor (VTF)was constructed by NDVI and DEM data from 2000 to 2018. Based on VTF classification , Vegetation-Topographic landscape index(VTLI) was calculated by FRAGSTATS to analyze the impact of VTLI change on runoff and sediment yield in Nandong underground river system（NURS）. The results showed that :(1) PD, IJI, LSI, SHDI were significantly positively correlated with runoff and sediment, while AI, CONNECT were significantly negatively correlated with runoff and sediment yield(P<0.05). LPI and DIVISION indices were not significantly correlated with discharge, but positively correlated with sediment yield. (2) PD, IJI, LSI and SHDI were the main promoting factors for runoff, while LSI and SHDI were the main promoting factors for sediment yield. CONNECT and AI were the main restrain factors of sediment yield, Which showed a downward trend. (3) In urban areas, VTF was decreased and has persistence trend. In basin-mountain margin areas, VTF was increased and has persistence trend. In mountain area, VTF was unchanged or not significantly increased but was anti-persistence trend. The change of landscape pattern indexes varied the runoff and sediment yield of NURS. The trend and persistence of VTF vary greatly in different geomorphic positions of NURS. These results will provide theoretical basis for watershed management and soil conservation of karst fragile ecosystem in southwest China. 

Simulating the spatial and temporal dynamics of landscapes using generic and complex models

庐山森林景观格局变化的长期动态模拟

The widespread and long—lasting impact of human activity on natural ecosystems indicates that land—use history must be treated as an integral aspect of ecological study and a critical component of conservation planning. The New England landscape has undergone a complete transformation as forests were converted to agriculture in the 18th and 19th centuries followed by succession to woodland as a result of widespread agricultural abandonment. Despite the prevalence of human impacts, the effect and longevity of land—use practices on modern forest conditions are poorly understood. In the present study of pitch pine—scrub oak vegetation on a sand plain in the Connecticut Valley of Massachusetts, we address the following questions: (1) what is the relative importance of human and natural disturbance and environmental factors in controlling vegetation composition, structure, and landscape patterns; (2) what are the mechanisms underlying human impacts on vegetation, and what is the duration of these impacts; and (3) what are the implications of land—use history for the interpretation and conservation of these communities? Sand plain vegetation was selected for investigation because the homogeneity of site conditions facilitates the interpretation of land—use and natural disturbance impacts, and because the uncommon vegetation and constituent species are priorities for conservation efforts. Paleoecological data suggest that pre—European fires were common on the study area, perhaps ignited by a large regional Indian population. The area was noted historically as an extensive pine plain and was used for wood products from the 18th to the mid—19th century. Eighty—two percent of the area was subsequently plowed for agriculture before being abandoned in the early 20th century. Soil analyses confirm the homogeneity of site conditions and suggest that land uses (plowing, woodlot/pasture) were determined according to ownership pattern rather than site factors. Previously cultivated parcels have distinct Ap (plow horizons) 15—33 cm deep, whereas uncultivated parcels have A horizons 3—10 cm in depth. Soil physical and chemical characteristics are similar among land uses and modern vegetation types. Aerial photographs document a dramatic transformation in plant cover over the last 50 yr. In 1939, the vegetation was grassland or shrub—heath (49%), open—canopy forest (29%), and scrub—oak shrublands (15%). In 1985, 73% of the study area was forested with pitch pine (40%), hardwood (12%), or mixed stands (21%), 9% was in open—canopy stands, and 3% was covered by grass or shrubs. Vegetation/land—use relations are striking. Pitch pine occurs almost exclusively (97%) on former plowed sites, whereas scrub oak stands occur preferentially (89%) on sites that have not been plowed. Land use explains the greatest variation in modern vegetation as well as the distribution and abundance of many taxa. Fire has been common across the study area but has influenced vegetation largely within patterns resulting from prior land use. Land—use patterns and factors controlling vegetation composition and structure are broadly paralleled at similar sites elsewhere in the Connecticut Valley. The study indicates that conservation biologists interested in preserving species, communities, and landscape patterns on sand plains in the northeastern United States need to incorporate a dynamic perspective of biological systems that includes the overriding impact of prior land use. In order to appreciate, study, and display these land—use and vegetation patterns it is essential to conserve the mosaic of assemblages and historical uses within a landscape setting.

<p>Vegetation not only controls but is also controlled by erosion processes. This tight feedback effect leads to the coevolution of vegetation and erosion patterns that modulate landform shape, and regulate many other landscape processes. These tight interactions are particularly important in semiarid landscapes. We have studied these interactions using a landform evolution model that accounts for the effect (and feedbacks) of spatially and temporally varying hydrologic and vegetation patterns.</p><p>We apply the modelling framework to improve our understanding of the coevolution of landforms and vegetation patterns in different semiarid landscapes in Australia. The vegetation of the selected sites is Acacia Aneura (Mulga) which covers vast areas of Australia.  These sites display a sparse vegetation cover and strong patterns of water redistribution, with sources located in the bare areas and sinks in the vegetation patches which characterize the observed hydrologic connectivity. This effect triggers high spatial variability of erosion/deposition rates that affects the evolving topography and induces feedbacks to the dynamic vegetation patterns. We run simulations for 1000 years using local rainfall and erosion and vegetation parameters previously calibrated for similar sites in the Northern territory. Our numerical modelling results are validated by comparing simulated and observed patterns of vegetation and landforms obtained from satellite, airborne remote sensing and field data. We further investigate the effect of alterations in hydrologic connectivity induced by climate change and/or anthropogenic activities, which affect water and sediment redistribution and can be linked to loss of resources leading to degradation.</p><p>Our simulations are able to reproduce observed banded vegetation and landform patterns for the Northern territory in Australia. We show that an increase in hydrologic connectivity can trigger changes in vegetation patterns inducing feedbacks with landforms leading to degraded states. These transitions display non-linear behaviour and in some cases can lead to thresholds with an abrupt reduction in productivity. Critical implications for effective long-term restoration efforts are discussed.</p>

The degradation of urban ecology, particularly in metropolitan areas distinguished by dense populations and impervious surfaces, presents a worldwide challenge linked to swift urban expansion. Despite extensive documentation of urbanization’s impact on broad regions or specific urban ecosystems over defined time periods, there remains a scarcity of studies investigating the spatiotemporal dynamics of landscape pattern (LP) changes in specific ecosystems at small-to-medium scales within inland megacities as a response to urbanization. Therefore, this work focused on the Bailuwan Wetland Park (BWP) in Chengdu, an inland megacity in southwestern China. Employing satellite imagery data from selected years spanning the previous decade (2010–2021, encompassing 2010, 2012, 2015, 2018, and 2021), this investigation delved into the influences of urbanization on the LP over various time-frames and across different land use/land cover (LULC) types. Our study revealed that urbanization has a significant impact on the patch-/landscape-level characteristics, including the class area (CA), number of patches (NP), patch density (PD), percentage of landscape (PLAND), aggregation index (AI), contagion index (CONTAG), largest patch index (LPI), landscape shape index (LSI), fractal dimension index (FRAC_MN), Shannon’s diversity (SHDI), and evenness index (SHEI). Over the period from 2010 to 2021, NP and PD experienced notable increases, while landscape shape (LSI/FRAC_MN) exhibited greater complexity and fragmentation (PLAND) intensified. Further, landscape heterogeneity (AI/CONTAG) and diversity (SHDI/SHEI) decreased. Particularly significant was the conversion of 52 ha of agricultural land to vegetation, resulting in heightened complexity and fragmentation in vegetation patterns. Additionally, the CA of lakes and rivers decreased following the establishment of the park, while the CA and NP of bare land presented significant increases. These findings suggest that rapid urbanization significantly influences the spatial–temporal dynamics of wetland landscape patterns. Consequently, it is imperative for society to prioritize the restoration and protection of urban constructed wetlands.

Estimating historical range and variation of landscape patch dynamics: limitations of the simulation approach