Present-day Landscape Research Articles

Vegetation and landscape dynamics under natural and anthropogenic forcing on the Azores Islands: A 700-year pollen record from the São Miguel Island

The Azores archipelago has provided significant clues to the ecological, biogeographic and evolutionary knowledge of oceanic islands. Palaeoecological records are comparatively scarce, but they can provide relevant information on these subjects. We report the palynological reconstruction of the vegetation and landscape dynamics of the São Miguel Island before and after human settlement using the sediments of Lake Azul. The landscape was dominated by dense laurisilvas of Juniperus brevifolia and Morella faya from ca. 1280 CE to the official European establishment (1449 CE). After this date, the original forests were replaced by a complex of Erica azorica/Myrsine africana forests/shrublands and grassy meadows, which remained until ca. 1800 CE. Extractive forestry, cereal cultivation (rye, maize, wheat) and animal husbandry progressed until another extensive deforestation (ca. 1774 CE), followed by the large-scale introduction (1845 CE) of the exotic forest species Cryptomeria japonica and Pinus pinaster, which shaped the present-day landscape. Fire was a significant driver in these vegetation changes. The lake levels experienced a progressive rise during the time interval studied, reaching a maximum by ca. 1778–1852 CE, followed by a hydrological decline likely due to a combination of climatic and anthropogenic drivers. Our pollen record suggests that São Miguel were already settled by humans by ca. 1287 CE, approximately one century and a half prior to the official historically documented occupation of the archipelago. The results of this study are compared with the few palynological records available from other Azores islands (Pico and Flores).

Quaternary evolution of the Southern Apennines coastal plains: a review

AbstractThe Quaternary evolution of the main coastal basins located along the southwestern margin of the Southern Apennines has been reconstructed by integrating the huge amount of existing stratigraphical and geomorphological data. The information produced in the last twenty years has shed new light on the recent (late Middle Pleistocene to Present) history of the Campanian and Sele plains or basins. During the early Quaternary, the analysed coastal basins originated as half-grabens in response to opening processes active since the late Tortonian in the southern Tyrrhenian back-arc basin. In some of these basins (e.g. the Campanian Plain), volcanism has also played an important role. In the inner sectors of the coastal basins, the complex interplay between block faulting, sedimentary inputs and glacioeustatic fluctuations gave rise to relative sea-level change and related coastline migrations, leading to the formation of the present-day coastal plains. In the Sele Plain basin, the construction of the present-day landscape mainly resulted from the substantial ceasing of subsidence in the final part of the Middle Pleistocene. Conversely, a strong contribution to the recent evolution of the Campanian Plain has been provided by abundant volcaniclastic aggradation, able to hinder the effect of the vertical motions that occurred in the last 100 ka.

Mapping the Historic Landscape: Historic Land-Use Assessment in Scotland

ABSTRACTThis paper discusses the recent completion of Scotland’s Historic Land-use Assessment (HLA) project, a long-term partnership between Historic Scotland and the Royal Commission on the Ancient and Historical Monuments of Scotland (RCAHMS) (now merged as Historic Environment Scotland) to map time-depth within the present-day landscape was completed in 2015. This paper places HLA within the wider context of historic landscape characterisation (HLC) in Europe and outlines some of the new insights and perspectives that this resource provides for Scotland’s landscapes. In particular, the historical complexity and time-depth inherent within the Scottish landscape is emphasised, along with the importance of HLA’s landscape-scale data and nationwide coverage. The paper finishes with a discussion of some of the possibilities and challenges for the future of HLA and HLC projects in general, concluding that HLA/HLC data have a significant part to play in understanding and communicating the role of the past in the formation of current landscapes and, in partnership with multidisciplinary data, helping to shape future landscapes.

Global Land Cover Data Bases and their Perspectives for Present-Day Landscapes Mapping

Land cover databases obtained as a result of processing space images from different imaging systems are used around the world for mapping landscapes/ecosystems at global and regional scales. For these purposes, the following databases are analyzed: the University of Maryland’s UMD Land Cover Classification for 1981-1994, DISCover land cover for 1992-1993, Global Land Cover 2000, GlobCover for 2009, and MODIS Land Cover for 2001-2012. On the basis of per pixel and per class analysis of UMD Land Cover Classification and Global Land Cover 2000 it was concluded that to obtain reliable results on the status of the land cover is possible only for certain categories. MODIS Land Cover data for 2001-2012, which may be combined with AVHRR data available for 1982-2006, are better suited for mapping land use changes of contemporary landscapes. The constraints and opportunities for using these databases, including the creation of a dynamic classification of contemporary landscapes on the basis of the typology of land use changes for 1980-2010 are considered. It is shown that the data on land cover reflect the prevailing geoecological functions of geosystems: environment regulatory (ecosystem), productive, industrial and residential, which can be the basis for a new classification system for modern landscapes.

Forest is Forest and Meadows are Meadows

Present-day landscapes are shaped by historical forces that combine natural change (generated by climate, geological processes etc.) with anthropogenic change (locally generated in interaction with larger political and economic forces). In the Jiuzhaigou region of Northern Sichuan, humans have shaped landscapes to their needs for at least 3,500 years. In recent centuries, landscape change has probably accelerated, particularly in response to changes in the political economy of the region since the late 19th century. At present, Amdo and Baima Tibetan communities in the region are faced with generally similar but locally differing political and economic pressures, including economic development, tourism, and policies of conservation and reforestation. The communities have reacted to these pressures in diverse ways that produce different landscape outcomes, demonstrating that neither local cultural landscape ideals alone nor policy prescriptions alone can explain current landscape configurations or predict the precise future impact of policies. However, constraints imposed by bureaucratic planning may lead to landscapes with diminished biodiversity and reduced adaptive capacity.

Controls on soil carbon storage from topography and vegetation in a rocky, semi-arid landscapes

Soil properties can exhibit strong spatial variation, even at the small catchment scale. Especially soil carbon pools in semi-arid, mountainous areas are highly uncertain because bulk density and stoniness are very heterogeneous and rarely measured explicitly. The effect of topographic and vegetation variables, on stoniness, bulk density and soil carbon has been explored in a 2.7km2 watershed of Sierra Morena in south Spain. Soil core samples were collected from 67 locations at 6 depths up to 0,3m. Stoniness and bulk density were measured with standard methods, total organic carbon through elemental analysis. These soil properties were then used to calculate carbon stock and related to solar insolation, elevation, slope, curvature, TWI, TPI, SPI and NDVI. Stone content depends on slope, indicating the importance of water erosion on long-term soil development. Spatial distribution of bulk density was found to be highly random. By means of conventional statistical methods, with the help of a random forest method, solar radiation and NDVI proved to be the key variable controlling soil carbon distribution. Total soil organic carbon stocks were 4.38kgm−2 on average, with stocks about double as high on north versus south-facing slopes. These results confirm the importance of the coupled soil moisture and vegetation dynamics on the carbon balance in semi-arid ecosystems. However, validation of the random forest model showed that the different covariates only explained 18% of the variation in the dataset. Apparently, present-day landscape and vegetation properties are not sufficient to fully explain the full variability in the soil carbon stocks in this complex terrain under natural vegetation. This is attributed to a high spatial variability in bulk density and stoniness, key variables controlling carbon stocks. Future improvement of mechanistic soil formation models could help estimating these soil properties better.

Long-term forest cover changes, within an agricultural region, in relation to environmental variables, Lubelskie province, Eastern Poland

Land cover changes result mainly from anthropogenic determinants (historical and socio-economic processes), but natural factors may also play an important role. The processes of deforestation and reforestation are important elements of present-day landscape changes in Central Europe. In this study, the relation of forest cover changes to environmental variables (topography and soils) within an important agricultural region of Poland, the Lubelskie province (25,000 km2), over the last 180 years was assessed. Three topographical maps (from 1830, 1930 and 2006) and other cartographic data were used to detect forest cover changes and their driving forces. Simple spatial index and supplementary statistical methods were applied to evaluate the relations. The first period (1830–1930) saw intensive deforestation as a result of increasing agricultural land use; forest cover decreased from 30 to 19 %. The second period (1930–2006) was characterised by an increase in forest area that now accounts for 23 % of the province. Although changes in forest cover are related to human activity, spatial patterns of deforested and reforested areas during the last 180 years corresponded to the diversity of environmental variables. Flat areas covered by fertile soils were deforested, while new forests appear mainly within sandy soils and steeper slopes. The study also showed that environmental variables had an impact on the structure of forest cover.

Detection and analysis of morphotectonic features utilizing satellite remote sensing and GIS: An example in SW Jordan

This study investigates the dominant orientations of morphological features and the relationship between these trends and the spatial orientation of tectonic structures in SW Jordan. Landsat 8 and hill-shaded images, constructed from 30m-resolution ASTER-GDEM data, were used for automatically extracting and mapping geological lineaments. The ASTER-GDEM was further utilized to automatically identify and extract drainage network. Morphological features were analyzed by means of azimuth frequency and length density distributions. Tectonic controls on the land surface were evaluated using longitudinal profiles of many westerly flowing streams. The profiles were taken directly across the northerly trending faults within a strong topographic transition between the low-gradient uplands and the deeply incised mountain front on the east side of the Dead Sea Fault Zone. Streams of the area are widely divergent, and show numerous anomalies along their profiles when they transect faults and lineaments. Five types of drainage patterns were identified: dendritic, parallel, rectangular, trellis, and modified dendritic/trellis. Interpretation and analysis of the lineaments indicate the presence of four main lineament populations that trend ~E–W, ~N–S, NE–SW, and NW–SE. Azimuthal distribution analysis of both the measured structures and drainage channels shows similar trends, except for very few differences in the prevailing directions. The similarity in orientation of lineaments, drainage system, and subsurface structural trends highlights the degree of control exerted by underlying structure on the surface geomorphological features. Faults and lineaments serve as a preferential conduit for surface running waters. The extracted lineaments were divided into five populations based on the main age of host rocks outcropping in the study area to obtain information about the temporal evolution of the lineament trends through geologic time. A general consistency in lineament trends over the different lithological units was observed, most probably because repeated reactivation of tectonism along preexisting deep structural discontinuities which are apparently crustal weakness zones. The reactivation along such inherited discontinuities under the present-day stress field is the most probable explanation of the complicated pattern and style of present-day landscape features in SW Jordan.

Analysis of the relationships between the spatial arrangement of palaeovalleys and contemporary valleys of Central Poland in the light of GIS methods

The article presents an example of application of selected GIS methods for showing connections between the course of palaeovalleys and contemporary valleys in Central Poland. The analysed area was shaped in the conditions of environment as early as the Palaeogene and Neogene, but the greatest impact on the present-day landscape came from the morphogenetic processes which operated in the Quaternary.Palaeogeographic studies of the analysed area often point to the possible dependencies between the contemporary landscape and its substrate, particularly as regards the valley system. In order to verify this hypothesis, on the basis of archival cartographic materials and a Digital Elevation Model of the current terrain, a procedure for conducting analyses with the use of commonly available GIS tools was proposed. Results of the conducted analysis allow for stating that the major river valleys of Central Poland in large part correspond to the arrangement of the fossil valley system, and the relationships are most easily noticeable for the largest valleys.

Coevolution of volcanic catchments in Japan

Abstract. Present-day landscapes have evolved over time through interactions between the prevailing climates and geological settings. Understanding the linkage between spatial patterns of landforms, soils, and vegetation in landscapes and their hydrological response is critical to make quantitative predictions in ungaged basins. Catchment coevolution is a theoretical framework that seeks to formulate hypotheses about the mechanisms and conditions that determine the historical development of catchments and how such evolution affects their hydrological response. In this study, we selected 14 volcanic catchments of different ages (from 0.225 to 82.2 Ma) in Japan. We derived indices of landscape properties (drainage density and slope–area relationship) as well as hydrological response (annual water balance, baseflow index, and flow–duration curves) and examined their relation with catchment age and climate (through the aridity index). We found a significant correlation between drainage density and baseflow index with age, but not with climate. The intra-annual flow variability was also significantly related to catchments age. Younger catchments tended to have lower peak flows and higher low flows, while older catchments exhibited more flashy runoff. The decrease in baseflow with catchment age is consistent with the existing hypothesis that in volcanic landscapes the major flow pathways change over time from deep groundwater flow to shallow subsurface flow. The drainage density of our catchments decreased with age, contrary to previous findings in a set of similar, but younger volcanic catchments in the Oregon Cascades, in which drainage density increased with age. In that case, older catchments were thought to show more landscape incision due to increasing near-surface lateral flow paths. Our results suggests two competing hypotheses on the evolution of drainage density in mature catchments. One is that as catchments continue to age, the hydrologically active channels retreat because less recharge leads to lower average aquifer levels and less baseflow. The other hypothesis is that the active channels do not undergo much surface dissection after the catchments reach maturity.

History and mechanisms for the expansion of the Badain Jaran Desert, northern China, since 20 ka: Geological and luminescence chronological evidence

Desert landscapes are widely distributed in the arid northern China. The Badain Jaran Desert (BJD) is located north-west of the Tengger Desert (TD) and Ulan Buh Desert (UBD), with the Yabrai and Bayan Ulan Mountains separating the BJD from the TD and UBD. Many sand belts with an orientation of NW-SE, which is similar to that of the prevailing sand-transporting winds, connect the BJD with the TD and UBD, forming the sand transportation routes from the BJD to the TD and UBD. Thus, these sand belts are sensitive to the expansion or shrinkage of the BJD, whose chronologies could be critical for understanding the evolution of the BJD. However, age data are still very limited. In this study, field investigation and optically stimulated luminescence (OSL) dating have been conducted in 14 profiles, and 24 OSL ages are obtained. The OSL ages range from approximately 15 ka to modern. Our results and previous chronological data revealed that the BJD’s expansion initiated at 20 ka, and the present-day landscape formed within the latest 2 ka with periodic expansions at 19–15, 11–9, 7.3 and 6–5 ka. We propose that these expansions of the BJD before ~5 ka and during the 0.9–0.8 ka interval were responses to regionally low effective moisture conditions in north-western China, while the expansions at ~2 ka and within the latest 200 years were likely triggered by intensified human activity.

Oblike prazgodovinske poljske razdelitve na Krasu

Traces of prehistoric land use and field division in the Karst were identified using airborne laser scanning imaging. They mostly include cairns and cairnfields, stock management structures such as funnels, pens, corrals and remnants of enclosed paths. We also identified the remains of regular field systems. The traces testify to an intensively shaped landscape that most likely dates to the Bronze Age. The next major transformation, which shaped the modern and present-day landscape, has taken place only in the last millennium and shows no continuity with the previous one.

Towards responsible geographies of memory: complexities of place and the ethics of remembering

Debates about the meanings of place often emerge when unsettled pasts resurface unexpectedly in ways that dislocate present-day land-uses. Such was the case for the IGU 2011 Regional Meeting in Chile, which was held in Santiago's Military Academy. When considering the geographical scholarship about place and memory, the debates resulting from the conference should not be surprising. Geographers have long examined the controversial processes of social memory and forgetting at places marked by state-perpetrated violence and have noted the unpredictability of group memory due to the translocal nature of how places are connected to peoples and pasts through socio-political networks, cultural and economic connections, and personal and shared emotional geographies. To understand the complexities of ethical relationships we have with places marked by violence, we look to another example, the Memorial and Museum Camp Westerbork in the Netherlands. The past is never ‘set in stone’ or stable in present-day landscapes. Just as the narratives associated with remembering and forgetting the past may change through time, so too do the spatial contexts of memory. When space-times shift unexpectedly, new social discussions about the significance of the past in the present may emerge. With both examples in mind, we conclude by making a case for the creation of “responsible geographies of memory”. We argue that it is our professional responsibility as geographers and our obligation as global citizens to: 1) acknowledge that landscapes often function as places of critical testimony for survivors; 2) problematize singular claims to the authenticity of place made through universal narratives and seemingly stable material landscapes; 3) create safe spaces of listening, wherein stories about place can be articulated and acknowledged by various stakeholders, while recognizing the moral complexities in representing violence through textual, visual and embodied means; and 4) recognize the progressive potential of places as cosmopolitan spaces of encounter and learning. By treating places marked by difficult pasts as cosmopolitan, hosts and visitors are invited to engage critically with the unfolding processes of memory politics, and adopt respectful approaches toward justice that includes caring for places and peoples in the past and present.

New pedoanthracological data for the long-term history of forest species at mid-high altitudes in the Queyras Valley (Inner Alps)

In the context of global change, the assessment of the past history and current dynamics of forest species is essential for improving our knowledge of the settlement and evolution of the present-day landscape. Several paleoecological approaches are well suited for reconstructing past landscapes and Holocene dynamics. Today, the subalpine forest of Queyras is composed primarily of larch, with lesser proportions of stone pine, mountain pine and fir. During the Holocene, the subalpine forest was subject to natural disturbances, particularly fires. By the end of the Atlantic period, human perturbations resulting from agro-sylvo-pastoral practices became an important factor, and this factor serves to explain the landscape dynamics and the dominance of certain woody species. In this study, a pedoanthracological approach was used to enhance existing knowledge of the history of forest species and to reach a good understanding of the processes that have shaped the current floristic assemblage.The results of the analyses of soil charcoal performed in this study provide the following new information: (i) a longer Holocene history for larch and stone pine, (ii) a lack of evidence for a natural presence of fir and (iii) a long-term history for Scots pine. The dates obtained reveal the early occurrence of recolonization by stone pine and larch following the last glaciation. The charcoals analyzed demonstrate the overall presence of stone pine, which is found throughout the studied history of the area. In terms of the changes presently occurring, among which both the abandonment of human land-use practices and climate change are especially important, the current conditions at mid-high altitudes might potentially allow the establishment of larch forests for a long period as preclimax ecosystems. The low frequency of fir in charcoal samples raises questions about the status and possible presence of fir in the past despite palynological evidence.

The spatial and temporal components of functional connectivity in fragmented landscapes.

Connectivity is key for understanding how ecological systems respond to the challenges of land-use change and habitat fragmentation. Structural and functional connectivity are both established concepts in ecology, but the temporal component of connectivity deserves more attention. Whereas functional connectivity is often associated with spatial patterns (spatial functional connectivity), temporal functional connectivity relates to the persistence of organisms in time, in the same place. Both temporal and spatial processes determine biodiversity responses to changes in landscape structure, and it is therefore necessary that all aspects of connectivity are considered together. In this perspective, we use a case study to outline why we believe that both the spatial and temporal components of functional connectivity are important for understanding biodiversity patterns in the present-day landscape, and how they can also help us to make better-informed decisions about conserving and restoring landscapes and improving resilience to future change.

Use of Satellite SAR for Understanding Long-Term Human Occupation Dynamics in the Monsoonal Semi-Arid Plains of North Gujarat, India

This work explores the spatial distribution of monsoonal flooded areas using ENVISAT C-band Advanced Synthetic Aperture Radar (ASAR) in the semi-arid region of N. Gujarat, India. The amplitude component of SAR Single Look Complex (SLC) images has been used to estimate the extent of surface and near-surface water dynamics using the mean amplitude (MA) of monsoonal (July to September) and post-monsoonal (October to January) seasons. The integration of SAR-derived maps (seasonal flooding maps and seasonal MA change) with archaeological data has provided new insights to understand present-day landscape dynamics affecting archaeological preservation and visibility. Furthermore, preliminary results suggest a good correlation between Mid-Holocene settlement patterns and the distribution and extension of seasonal floodable areas within river basin areas, opening interesting inroads to study settlement distribution and resource availability in past socio-ecological systems in semi-arid areas.

Forest fires within a temperate landscape: A decadal and millennial perspective from a sandstone region in Central Europe

In Europe, fire is considered an integral part of forest dynamics only in the Mediterranean and in Fenno-Scandinavia. In Central Europe, the ecological role of fire is largely neglected and deemed unimportant. To fill this knowledge gap, we studied ancient and recent fires in temperate coniferous forests of a sandstone landscape. We used palaeoecological and contemporary forestry data to reveal wildfire events in the present-day landscape and in the distant past. Using linear regression and the ENFA method, we identified the factors influencing fire occurrences in the landscape on two time scales. Analyses of soil charcoal concentrations correspond with contemporary forestry data. The main driving factors affecting the incidence of fires were topographic features, namely the heat load index and presence of rocks. Additional important factors were forest composition features, especially the abundance of Pinus sylvestris. Even though the landscape is populated and attractive to tourists, present-day anthropogenic factors, surprisingly, have only marginal effects. Fires have been occurring in similar fire-prone habitats at least since the Subatlantic period, regardless of whether they were caused by humans or lightning. Our results therefore show that fire affects long-term forest vegetation development also in temperate forests of Central Europe. This has far reaching consequences for forest management because, contrary to prevailing beliefs, fire must be considered a natural driver of forest vegetation patterns even in this temperate region.

Late Quaternary environmental evolution of the intermontane Valle Caudina basin, southern Italy

The Valle Caudina intermontane basin in the southern Apennines (Italy) lies between the Mt. Taburno on the North and the Avella–Partenio mountains on the South. An analysis of its present-day landscape, and of its stratigraphic and geoarcheological features, has been carried out to reconstruct the Late Quaternary evolution of the basin, filled by alluvial, colluvial and volcaniclastic deposits. The depositional pattern and geomorphological context allow to recognize lacustrine and fluvial–lacustrine sediments, interbedded with ignimbritic layers originating from the Phlegrean Fields and with a Vesuvius pumice level, that represent significant chronological markers. The two lacustrine episodes are connected with volcanic events radiometrically dated (De Vivo et al. in Mt. Somma Vesuvius and Volcanism of the Campania Plain. Spec Issue, Mineral Petrol. Springer, Berlin, vol 73, pp 47–65, 2001). The older predates the Campanian Ignimbrite deposit (~39 kyr BP), while the younger deposited before 5 kyr BP, as indicated by the recovery of Neolithic artifacts. The presence of Roman ruins in the center of the valley suggests that the lake has suffered a substantial downsizing or has disappeared between 5 kyr BP and the Roman Age. A clayey deposit testifies a first lacustrine phase, which has affected the whole plain. Above this unit, heterogeneous deposits indicate the end of the lacustrine phase and the beginning of a clear fluvial sedimentation. Volcaniclastic deposits from the erosion of the Campanian Ignimbrite follow. They are overlapped by a widespread second lacustrine unit. Finally, a reworked and altered volcaniclastic level closes the stratigraphic sequence, while particularly fertile topsoil covered all the plain.

Millennial disturbance-driven forest stand dynamics in the Eastern Canadian taiga reconstructed from subfossil logs

1. Although wildfire is the main natural disturbance factor driving changes in the North American boreal forest, understanding how the fire history of the last millennium shaped the present-day landscape diversity is a difficult task due to the lack of palaeoecological reconstructions with high spatial (few hundreds of square metres) and temporal (annual) resolutions. 2. We combined a detailed inventory of the present-day lakeshore forest of two lakes of the Eastern Canadian taiga with the dendrochronological dating of the subfossil logs that accumulated in the lit-toral zones facing these shores. Our objective was to compare the millennial impact of wildfires among stands of various structures and compositions. Past stem densities and fire years were reconstructed from log recruitment rates and dating of charred logs. 3. Multivariate analysis of the present-day lakeshore forest revealed three and two homogeneous shore segments per site (i.e. clusters). Cluster 1 at both sites exhibited denser forest, higher dead wood values and a higher percentage of balsam fir, a fire-sensitive species. 4. In total, 426 and 611 subfossil logs (mostly black spruce) were crossdated over the last ~1400 years. Their dendrochronological analysis confirmed that each lakeshore cluster, identified from the traits of the present-day forest, experienced a specific fire history over the last millennium (i.e. 0–5 fires of variable severity) that locally influenced forest composition, tree density and growth. Each fire triggered a specific forest structure trajectory characterized by a different stem density and rate of recovery. 5. Synthesis. This study provides a long-term perspective that helps explain how the present-day landscape diversity in the Eastern Canadian taiga reflects the site-specific fire history over the last millennium. Fires have caused persistent and cumulative impacts resulting in a progressive opening of the forest cover along with balsam fir exclusion. Present-day landscapes are mosaics of forest stands characterized by different times since fire and different post-fire forest structure trajectories.

Futures Past

These maps, based on research by the San Francisco Estuary Institute’s Center for Resilient Landscapes, reconstruct California ecosystems as they were in the late 18th and early 19th centuries, and compare them to present-day landscapes. They are designed to provide an understanding of the complexity and diversity of California ecosystems, to help explain how landscapes worked, to track persistence and change, and to identify potential future scenarios. The changes made evident when the maps are compared remind us of the enormous power we have to shape the landscapes we inhabit, and of the wide range of potential options available—options to create diverse, functional, and beautiful landscapes, inspired by the past and grounded in local potential—as we imagine and then create the future.