Analysis of temporal diversity of precipitation along with biodiversity of Holdridge life zones

The response of natural vegetation to climate change is of global concern. In this research, changes in the spatial pattern of major terrestrial ecosystems from 1956 to 2006 in Inner Mongolia of China were analyzed with the Holdridge Life Zone (HLZ) model in a GIS environment, and net primary production (NPP) of natural vegetation was evaluated with the Synthetic model, to determine the effect of climate change on the ecosystem. The results showed that climate warming and drying strongly influenced ecosystems. Decreased precipitation and the subsequent increase in temperature and potential evapotranspiration caused a severe water deficiency, and hence decreased ecosystem productivity. Climate change also influenced the spatial distribution of HLZs. In particular, new HLZs began to appear, such as Warm temperate desert scrub in 1981 and Warm temperate thorn steppe in 2001. The relative area of desert (Cool temperate desert scrub, Warm temperate thorn steppe, Warm temperate desert scrub, Cool temperate desert and Warm temperate desert) increased by 50.2% over the last half century, whereas the relative area of forest (Boreal moist forest and Cool moist forest) decreased by 36.5%. Furthermore, the area of Cool temperate steppe has continuously decreased at a rate of 5.7% per decade; if the current rate of decrease continues, this HLZ could disappear in 173 years. The HLZs had a large shift range with the mean center of the relative life zones of desert shifting northeast, resulting a decrease in the steppe and forest area and an increase in the desert area. In general, a strong effect of climate change on ecosystems was indicated. Therefore, the important role of climate change must be integrated into rehabilitation strategies of ecosystem degradation of Inner Mongolia.

Rarely considered in environmental assessment methods, potential land use impacts on a series of ecosystem services must be accounted for in widely used decision-making tools such as life cycle assessment (LCA). The main goal of this study is to provide an operational life cycle impact assessment characterization method that addresses land use impacts at a global scale by developing spatially differentiated characterization factors (CFs) and assessing the extent of their spatial variability using different regionalization levels. The proposed method follows the recommendations of previous work and falls within the framework and principles for land use impact assessment established by the United Nations Environment Programme/Society of Environmental Toxicology and Chemistry Life Cycle Initiative. Based on the spatial approach suggested by Saad et al. (Int J Life Cycle Assess 16: 198–211, 2011), the intended impact pathways that are modeled pertain to impacts on ecosystem services damage potential and focus on three major ecosystem services: (1) erosion regulation potential, (2) freshwater regulation potential, and (3) water purification potential. Spatially-differentiated CFs were calculated for each biogeographic region of all three regionalization scale (Holdridge life regions, Holdridge life zones, and terrestrial biomes) along with a nonspatial world average level. In addition, seven land use types were assessed considering both land occupation and land transformation interventions. A comprehensive analysis of the results indicates that, when compared to all resolution schemes, the world generic averaged CF can deviate for various ecosystem types. In the case of groundwater recharge potential impacts, this range varied up to factors of 7, 4.7, and 3 when using the Holdridge life zones, the Holdridge regions, and the terrestrial biomes regionalization levels, respectively. This validates the importance of introducing a regionalized assessment and highlights how a finer scale increases the level of detail and consequently the discriminating power across several biogeographic regions, which could not have been captured using a coarser scale. In practice, the implementation of such regionalized CFs suggests that an LCA practitioner must identify the ecosystem in which land occupation or transformation activities occur in addition to the traditional inventory data required—namely, the land use activity and the inventory flow. The variability of CFs across all three regionalization levels provides an indication of the uncertainty linked to nonspatial CFs. Among other assumptions and value choices made throughout the study, the use of ecological borders over political boundaries was deemed more relevant to the interpretation of environmental issues related to specific functional ecosystem behaviors.

Modeling impacts of projected land use and climate changes on the water balance in the Baro basin, Ethiopia

Ecological models have predicted shifts in forest biomes, yet there have been very few studies that have looked at the implications on carbon stocks due to these shifts. Carbon is closely correlated to biomass and constitutes an important characteristic of the forest ecosystem. It has implications for conservation and land use practices, especially for climate change mitigation strategies currently under discussion, such as REDD+. This study couples the Holdridge Life Zone (HLZ) classification with the ECHAM5 model, to evaluate the impacts of climate change using the Special Report on Emissions Scenarios (SRES) A2, A1B and B1 for the Central American region. We utilize methodologies which combine biophysical variables with model output to assess the impacts on carbon stocks for two time periods, 2000 and 2100, . Results show that overall, the tropical category of the HLZ classification gains area as a result of one type of HLZ shifting to another forest type. In many cases the shifts result in some categories of HLZ being lost in their entirety. Elevation-associated life zones are particularly vulnerable to future climatic changes. A strong point of our approach is that differences between disaggregate regional and aggregate country levels can be compared. We suggest that a critical focus of conservation and management efforts should be concentrated on where vulnerable biomes are at most risk (biomes that shift and/or reduce fall under the vulnerable category).

Abstract. Since the 1950s, Europe has undergone large shifts in climate and land cover. Previous assessments of past and future changes in evapotranspiration or streamflow have either focussed on land use/cover or climate contributions or on individual catchments under specific climate conditions, but not on all aspects at larger scales. Here, we aim to understand how decadal changes in climate (e.g. precipitation, temperature) and land use (e.g. deforestation/afforestation, urbanization) have impacted the amount and distribution of water resource availability (both evapotranspiration and streamflow) across Europe since the 1950s. To this end, we simulate the distribution of average evapotranspiration and streamflow at high resolution (1 km2) by combining (a) a steady-state Budyko model for water balance partitioning constrained by long-term (lysimeter) observations across different land use types, (b) a novel decadal high-resolution historical land use reconstruction, and (c) gridded observations of key meteorological variables. The continental-scale patterns in the simulations agree well with coarser-scale observation-based estimates of evapotranspiration and also with observed changes in streamflow from small basins across Europe. We find that strong shifts in the continental-scale patterns of evapotranspiration and streamflow have occurred between the period around 1960 and 2010. In much of central-western Europe, our results show an increase in evapotranspiration of the order of 5 %–15 % between 1955–1965 and 2005–2015, whereas much of the Scandinavian peninsula shows increases exceeding 15 %. The Iberian Peninsula and other parts of the Mediterranean show a decrease of the order of 5 %–15 %. A similar north–south gradient was found for changes in streamflow, although changes in central-western Europe were generally small. Strong decreases and increases exceeding 45 % were found in parts of the Iberian and Scandinavian peninsulas, respectively. In Sweden, for example, increased precipitation is a larger driver than large-scale reforestation and afforestation, leading to increases in both streamflow and evapotranspiration. In most of the Mediterranean, decreased precipitation combines with increased forest cover and potential evapotranspiration to reduce streamflow. In spite of considerable local- and regional-scale complexity, the response of net actual evapotranspiration to changes in land use, precipitation, and potential evaporation is remarkably uniform across Europe, increasing by ∼ 35–60 km3 yr−1, equivalent to the discharge of a large river. For streamflow, effects of changes in precipitation (∼ 95 km3 yr−1) dominate land use and potential evapotranspiration contributions (∼ 45–60 km3 yr−1). Locally, increased forest cover, forest stand age, and urbanization have led to significant decreases and increases in available streamflow, even in catchments that are considered to be near-natural.

<em>Abstract.</em>—Four criteria are used to evaluate viability during recovery planning for anadromous Pacific salmonid <em>Oncorhynchus </em>spp. populations listed under the U.S. Endangered Species Act: abundance, productivity, spatial structure, and diversity. Better approaches to evaluate spatial structure and diversity are needed so that potential outcomes of recovery actions can be more fully evaluated. In this chapter, we describe several approaches to evaluating spatial structure and diversity in recovery planning using data that were currently available from salmonid population modeling efforts and spatial analyses, especially of habitat data. We employed a case history approach using information developed during recovery planning for the Chinook salmon <em>O. tshawytscha </em>Evolutionarily Significant Unit (ESU) in Puget Sound. Multiple metrics of spatial structure and diversity were developed from outputs of fish population models and spatial habitat data for different land use scenario. We included analyses at several spatial scales. At the population level, we evaluated spatial structure and diversity of two Chinook salmon populations associated with the Snohomish River Basin, the Skykomish and Snoqualmie. We found that changes in spatial structure and diversity varied between the two populations when historical (baseline) and current conditions (a future condition expected if no significant changes occurred in the present rate and type of land use actions) were compared. Changes were more pronounced for the Skykomish population than for the Snoqualmie population. At the watershed scale, we analyzed changes in ecological diversity in six watersheds. Of the six watersheds considered, there was little evidence of a change in ecological diversity between historical and current habitat conditions (as reflected by changes in adult spawner and juvenile rearing capacities) in three watersheds (Dungeness, Snohomish, and Stillaguamish) while a more significant change in diversity was indicated in three other watersheds (Green, Puyallup, and Elwha). Changes in spatial structure of the Puget Sound ESU were indicated between historical and current conditions when comparing the proportion of spawners associated with each of the five biogeographical planning units. We recommend future work is needed to evaluate the effects of hatcheries and harvest on spatial structure and diversity, develop and test other metrics, and include other life stages such as those associated with estuarine and Puget Sound habitats.

Scenarios of potential vegetation distribution in the different gradient zones of Qinghai-Tibet Plateau under future climate change

Natural soil pipes are now recognized as potentially significant elements in hillslope drainage systems, sometimes developing into open channel tributaries or contributing often substantial volumes of quick flow to streams. However, there has been no detailed, long‐term monitoring study of the evolution of pipe networks to indicate how permanent they are or how readily they may develop into open channels. This paper reports a resurvey of a section of stream bank in the English Peak District and compares it with the original survey 35 years previous. Comparison of the distribution, size, and shape of pipes on both banks of a 250 m stretch of the stream reveals significant changes. There were no cases of roof collapse forming new open channels. However, there has been a significant change in land use within the basin, with afforestation of the east bank. The resurvey shows a marked reduction in the number and size of pipes on the forested bank, but no significant change on the opposite bank that has remained moorland. The number of pipe outlets on the afforested bank halved over the period, and their mean diameter has reduced by 30%. In combination with the reduced number the smaller size resulted in a 71% reduction in the total area of stream bank occupied by pipe outlets on the forested bank. It is postulated that the change is primarily due to a change in the amount of throughflow beneath the forest caused by an increase in evapotranspiration.

Changes in Holdridge Life Zone diversity in the Xinjiang Uygur Autonomous Region (XUAR) of China over the past 40 years

Natural ecosystems, whose components are the results of natural selection, are sustainable; most are productive, responsive to pests, and retentive of nutrients. Thus, they are appropriate models on which to base the design of new systems of land use. Abiotic and biotic stressors are related non-linearly; the nadir of total stress being mid-way along a gradient of environmental harshness. Superimposing the stress functions on Holdridge's life zone chart yields four broad categories of environments for agriculture: climates where annual rainfall is similar to potential evapotranspiration, plus three other categories that are either too cold, too arid, or too wet. Extremely cold lands have no potential for agriculture. Lands that are arid or infertile can be used successfully, although the cost of compensating for environmental limitations increases exponentially with increasing abiotic stress. Grazing animals (which act as trophic buffers between people and environment) have proven successful in dry and infertile environments. The humid tropical lowlands epitomise environments of low abiotic stress but overwhelming biotic intricacy. Here it pays to imitate natural systems rather than struggle to impose simplicity on ecosystems that are inherently complex. The keys to success are to (i) channel productivity into outputs of nutritional and economic importance, (ii) maintain adequate diversity to compensate for losses in a system simple enough to be horticulturally manageable, (iii) manage plants and herbivores to facilitate associational resistance and not associational susceptibility, and (iv) use perennial plants to maintain soil fertility, guard against erosion, and make full use of resources.

Reliable estimates of how human activities may affect wildlife populations are critical for making scientifically sound resource management decisions. A significant issue in estimating the consequences of management, development, or conservation measures is the need to account for a variety of biotic and abiotic factors, such as land use and climate change, that interact over time altering wildlife habitats and populations. The snow leopard Panthera uncia (Schreber, 1775), as a vulnerable species, is extremely sensitive to indirect impacts of climate change. Given that it is highly difficult undertaking conservation measures on the entire range of snow leopards, identifying hotspots for conservation is necessary. This study was conducted in Bagrot and Haramosh valleys, in the Trans-Himalayan region, to evaluate the impacts of climate and human pressure on snow leopard habitat. Hybrid classification of Landsat satellite data for 2010 and 2020 was performed to elucidate land use changes that suggested a decrease in permanent snow by 10 % and 3 % in Haramosh and Bagrot while an increase in settlements cover by 16 % and 23 %, respectively. Life zone comparison for 2010 and 2020 using the Holdridge life zone (HLZ) classification system disclosed a change from three life zones to five life zones in Haramosh, and four life zones to five life zones in Bagrot, caused by a temperature increase of 2°C to 3°C, indicating that the area is becoming more and more suitable for settlements and less favorable for snow leopards. This study underlines again that mountainous regions are more vulnerable to the impacts of climate change. Warming weather is making survival more difficult for snow leopards. Although they are resilient to the direct effects of climate change, indirect impacts like avalanches, flash floods, urbanization, and human-wildlife conflict make them more vulnerable and threaten their survival. Thus, we recommend establishing further protected areas, better controlling illegal wildlife trade, and conducting genetic studies to understand impacts on snow leopards and rangeland management, livelihood improvement, and human-wildlife conflict reductions.

Soil and water characteristics in micro basins with different land uses/land cover (LULC) can influence riparian vegetation diversity, stream water quality, and benthic diatom diversity. We analyzed 18 streams in the upper part of the La Antigua River basin, México, surrounded by cloud forests, livestock pastures, and coffee plantations. Concentrations of P, C, and N were elevated in the humus of forested streams compared to other land uses. In contrast, cations, ammonium, and total suspended solids (TSS) of water streams were higher in pastures and coffee plantations. These results indicate that LULC affects stream chemistry differently across land uses. Vegetation richness was highest (86-133 spp.) in forest streams and lowest in pastures (46-102), whereas pasture streams had the greatest richness of diatoms (9-24), likely due to higher light and temperatures. Some soil and water characteristics correlated with both true diversity and taxonomic diversity; soil carbon exchange capacity (CEC) correlated with vegetation diversity (r = 0.60), while water temperature correlated negatively (r = - 0.68). Diatom diversity was related to soil aluminum (r = - 0.59), magnesium (r = 0.57), water phosphorus (r = 0.88), and chlorophyll (r = 0.75). These findings suggest that land use affects riparian vegetation, while physical and chemical changes influence diatom diversity in stream water and soil. The lack of correlation between vegetation and diatom diversity indicates that one cannot predict the other. This research is an essential first step in understanding how land use changes impact vegetation and diatom diversity in mountain landscapes, providing valuable insights for environmental monitoring and conservation efforts in tropical cloud forests.

This study investigates the potential and applicability of variable infiltration capacity (VIC) hydrological model to simulate different hydrological components of the Upper Bhima basin under two different Land Use Land Cover (LULC) (the year 2000 and 2010) conditions. The total drainage area of the basin was discretized into 1694 grids of about 5.5 km by 5.5 km: accordingly the model parameters were calibrated at each grid level. Vegetation parameters for the model were prepared using temporal profile of Leaf Area Index (LAI) from Moderate-Resolution Imaging Spectroradiometer and LULC. This practice provides a methodological framework for the improved vegetation parameterization along with region-specific condition for the model simulation. The calibrated and validated model was run using the two LULC conditions separately with the same observed meteorological forcing (1996–2001) and soil data. The change in LULC has resulted to an increase in the average annual evapotranspiration over the basin by 7.8%, while the average annual surface runoff and baseflow decreased by 18.86 and 5.83%, respectively. The variability in hydrological components and the spatial variation of each component attributed to LULC were assessed at the basin grid level. It was observed that 80% of the basin grids showed an increase in evapotranspiration (ET) (maximum of 292 mm). While the majority of the grids showed a decrease in surface runoff and baseflow, some of the grids showed an increase (i.e. 21 and 15% of total grids—surface runoff and baseflow, respectively).

With the rapid development of urbanization and population growth, the ecological environment in the Yellow River Delta has undergone significant changes. In this study, Landsat satellite data and Google Earth Engine (GEE) were utilized to dynamically evaluate the changes in eco-environmental quality in the Yellow River Delta region using the remote sensing ecological index (RSEI). Additionally, the CASA model was used to estimate net primary productivity (NPP) and explore the relationship between vegetation NPP, land-use and land-cover change (LUCC), and eco-environmental quality to reveal the complexity and related factors of eco-environmental quality changes in this region. The results show that: (1) Over the past 20 years, the eco-environmental quality in the Yellow River Delta region has changed in a “V” shape. The eco-environmental quality near the Yellow River Basin is relatively better, forming a diagonal “Y” shape, while the areas with poorer eco-environmental quality are mainly distributed in the coastal edge region of the Yellow River Delta. (2) The response of vegetation NPP to eco-environmental quality in the Yellow River Delta region is unstable. (3) Urban construction land in the Yellow River Delta region is strongly correlated with RSEI, and the absolute value of the dynamic degree of land use is as high as 8.78%, with significant land transfer changes. The correlation between arable land and RSEI is weak, while coastal mudflats are negatively correlated with RSEI, with the minimum absolute value of the dynamic degree of land use being −1.01%, and significant land transfer changes. There is no correlation between forest land and RSEI. Our research results can provide data support for the eco-environmental protection and sustainable development of the Yellow River Delta region and help local governments to take corresponding measures.

Fire regime changes are considered a major threat to future biodiversity in the Mediterranean Basin. Such predictions remain uncertain, given that fire regime changes and their ecological impacts occur over timescales that are too long for direct observation. Here we analyse centennial- and millennial-scale shifts in fire regimes and compositional turnover to track the consequences of fire regime shifts on Mediterranean vegetation diversity. We estimated rate-of-change, richness and compositional turnover (beta diversity) in 13 selected high-resolution palaeoecological records from Mediterranean Iberia and compared these with charcoal-inferred fire regime changes. Event sequence analysis showed fire regime shifts to be significantly temporally associated with compositional turnover, particularly during the last three millennia. We find that the timing and direction of fire and diversity change in Mediterranean Iberia are best explained by long-term human–environment interactions dating back perhaps 7500 years. Evidence suggests that Neolithic burning propagated a first wave of increasing vegetation openness and promoted woodland diversity around early farming settlements. Landscape transformation intensified around 5500 to 5000 cal. yr BP and accelerated during the last two millennia, as fire led to permanent transitions in ecosystem state. These fire episodes increased open vegetation diversity, decreased woodland diversity and significantly altered richness on a regional scale. Our study suggests that anthropogenic fires played a primary role in diversity changes in Mediterranean Iberia. Their millennia-long legacy in today’s vegetation should be considered for biodiversity conservation and landscape management.