Elevational shifts, biotic homogenization and time lags in vegetation change during 40 years of climate warming

Global climate warming is expected to be a new factor influencing vegetation redistribution and productivity in the XXI century. In this paper possible vegetation change in Mountain Altai under global warming is evaluated. The attention is focused on forest vegetation being one of the most important natural resources for the regional economy. A bioclimatic model of correlation between vegetation and climate is used to predict vegetation change (Parfenova, Tchebakova 1998). In the model, a vegetation class — an altitudinal vegetation belt (mountain tundra, dark- coniferous subalpine open woodland, light-coniferous subgolets open woodland, dark-coniferous mountain taiga, light-coniferous mountain taiga, chern taiga, subtaiga and forest-steppe, mountain steppe) is predicted from a combination of July Temperature (JT) and Complex Moisture Index (CMI). Borders between vegetation classes are determined by certain values of these two climatic indices. Some bioclimatic regularities of vegetation distribution in Mountain Altai have been found: 1. Tundra is separated from taiga by the JT value of 8.5°C; 2. Dark- coniferous taiga is separated from light-coniferous taiga by the CMI value of 2.25; 3. Mountain steppe is separated from the forests by the CMI value of 4.0. 4. Within both dark-coniferous and light-coniferous taiga, vegetation classes are separated by the temperature factor. For the spatially model of vegetation distribution in Mountain Altai within the window 84 E — 90 E and 48 N — 52 N, the DEM (Digital Elevation Model) was used with a pixel of 1 km resolution. In a GIS Package IDRISI for Windows 2.0, climatic layers were developed based on DEM and multiple regressions relating climatic indices to physiography (elevation and latitude). Coupling the map of climatic indices with the authors' bioclimatic model resulted into a vegetation map for the region of interest. Visual comparison of the modelled vegetation map with the observed geobotanical map (Kuminova, 1960; Ogureeva, 1980) showed a good similarity between them. The new climatic indices map was developed under the climate change scenario with summer temperature increase 2°C and annual precipitation increase 20% (Menzhulin, 1998). For most mountains under such climate change scenario vegetation belts would rise 300—400 m on average. Under current climate, the dark-coniferous and light-coniferous mountain taiga forests dominate throughout Mountain Altai. The chern forests are the most productive and floristically rich and are also widely distributed. Under climate warming, light-coniferous mountain taiga may be expected to transform into subtaiga and forest-steppe and dark-coniferous taiga may be expected to transform partly into chern taiga. Other consequences of warming may happen such as the increase of forest productivity within the territories with sufficient rainfall and the increase of forest fire occurrence over territories with insufficient rainfall.

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Links between spring snow cover and long-term alpine vegetation change

10.5194/egusphere-egu2020-8737 ◽

2020 ◽

Author(s):

Shengwei Zong ◽

Christian Rixen

Keyword(s):

Remote Sensing ◽

Snow Cover ◽

Plant Species ◽

Climate Warming ◽

Vegetation Change ◽

Alpine Vegetation ◽

Alpine Ecosystems ◽

Snow Cover Extent ◽

The Relationship

Snow is an important environmental factor determining distributions of plant species in alpine ecosystems. During the past decades, climate warming has resulted in significant reduction of snow cover extent globally, which led to remarkable alpine vegetation change. Alpine vegetation change is often caused by the combined effects of increasing air temperature and snow cover change, yet the relationship between snow cover and vegetation change is currently not fully understood. To detect changes in both snow cover and alpine vegetation, a relatively fine spatial scales over long temporal spans is necessary. In this study in alpine tundra of the Changbai Mountains, Northeast China, we (1) quantified spatiotemporal changes of spring snow cover area (SCA) during half a century by using multi-source remote sensing datasets; (2) detected long-term vegetation greening and browning trends at pixel level using Landsat archives of 30 m resolution, and (3) analyzed the relationship between spring SCA change and vegetation change. Results showed that spring SCA has decreased significantly during the last 50 years in line with climate warming. Changes in vegetation greening and browning trend were related to distributional range dynamics of a dominant indigenous evergreen shrub Rhododendron aureum, which extended at the leading edge and retracted at the trailing edge. Changes in R. aureum distribution were probably related to spring snow cover changes. Areas with decreasing R. aureum cover were often located in snow patches where probably herbs and grasses encroached from low elevations and adjacent communities. Our study highlights that spring SCA derived from multi-source remote sensing imagery can be used as a proxy to explore relationship between snow cover and vegetation change in alpine ecosystems. Alpine indigenous plant species may migrate upward following the reduction of snow-dominated environments in the context of climate warming and could be threatened by encroaching plants within snow bed habitats.

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Roots in the tundra : relations between climate warming and root biomass and implications for vegetation change and carbon dynamics

10.18174/385684 ◽

2016 ◽

Author(s):

Peng Wang

Keyword(s):

Climate Warming ◽

Root Biomass ◽

Vegetation Change ◽

Carbon Dynamics

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Four decades of plant community change along a continental gradient of warming

10.1101/313379 ◽

2018 ◽

Author(s):

Antoine Becker-Scarpitta ◽

Steve Vissault ◽

Mark Vellend

Keyword(s):

Climate Warming ◽

Vegetation Change ◽

High Sensitivity ◽

Warming Trend ◽

Community Change ◽

Individual Species ◽

Eastern Canada ◽

Recent Warming ◽

Temperature Indices ◽

Distribution Shifts

AbstractMany studies of individual sites have revealed biotic changes consistent with climate warming (e.g., upward elevational distribution shifts), but our understanding of the tremendous variation among studies in the magnitude of such biotic changes is minimal. In this study we re-surveyed forest vegetation plots 40 years after the initial surveys in three protected areas along a west-to-east gradient of increasingly steep recent warming trends in eastern Canada (Québec). Consistent with the hypothesis that climate warming has been an important driver of vegetation change, we found an increasing magnitude of changes in species richness and composition from west to east among the three parks. For the two mountainous parks, we found no changes in elevational species’ distributions in the eastern most park where warming has been minimal (Forillon Park), and significant upward distribution shifts in the centrally located park where the recent warming trend has been marked (Mont-Mégantic). Community temperature indices (CTI), reflecting the average affinities of locally co-occurring to temperature conditions across their geographic ranges (“species temperature indices”), did not change over time as predicted. However, close examination of the underpinnings of CTI values suggested a high sensitivity to uncertainty in individual species’ temperature indices, and so a potentially limited responsiveness to warming. Overall, by testing a priori predictions concerning variation among parks in the direction and magnitude of vegetation changes, we have provided stronger evidence for a link between climate warming and biotic responses than otherwise possible, and provided a potential explanation for large variation among studies in warming-related biotic changes.

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Biophysical Determinants of Shifting Tundra Vegetation Productivity in the Beaufort Delta Region of Canada

Ecosystems ◽

10.1007/s10021-021-00725-6 ◽

2022 ◽

Author(s):

Jordan H. Seider ◽

Trevor C. Lantz ◽

Txomin Hermosilla ◽

Michael A. Wulder ◽

Jonathan A. Wang

Keyword(s):

Random Forests ◽

Climate Warming ◽

Vegetation Change ◽

Vegetation Index ◽

Future Research ◽

Delta Region ◽

Vegetation Productivity ◽

Tundra Vegetation ◽

Glaciofluvial Deposits ◽

The Impact

AbstractTemperature increases across the circumpolar north have driven rapid increases in vegetation productivity, often described as ‘greening’. These changes have been widespread, but spatial variation in their pattern and magnitude suggests that biophysical factors also influence the response of tundra vegetation to climate warming. In this study, we used field sampling of soils and vegetation and random forests modeling to identify the determinants of trends in Landsat-derived Enhanced Vegetation Index, a surrogate for productivity, in the Beaufort Delta region of Canada between 1984 and 2016. This region has experienced notable change, with over 71% of the Tuktoyaktuk Coastlands and over 66% of the Yukon North Slope exhibiting statistically significant greening. Using both classification and regression random forests analyses, we show that increases in productivity have been more widespread and rapid at low-to-moderate elevations and in areas dominated by till blanket and glaciofluvial deposits, suggesting that nutrient and moisture availability mediate the impact of climate warming on tundra vegetation. Rapid greening in shrub-dominated vegetation types and observed increases in the cover of low and tall shrub cover (4.8% and 6.0%) also indicate that regional changes have been driven by shifts in the abundance of these functional groups. Our findings demonstrate the utility of random forests models for identifying regional drivers of tundra vegetation change. To obtain additional fine-grained insights on drivers of increased tundra productivity, we recommend future research combine spatially comprehensive time series satellite data (as used herein) with samples of high spatial resolution imagery and integrated field investigations.

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Rapid Changes in Ground Vegetation of Mature Boreal Forests—An Analysis of Swedish National Forest Inventory Data

Forests ◽

10.3390/f12040475 ◽

2021 ◽

Vol 12 (4) ◽

pp. 475

Author(s):

Bengt Gunnar Jonsson ◽

Jonas Dahlgren ◽

Magnus Ekström ◽

Per-Anders Esseen ◽

Anton Grafström ◽

...

Keyword(s):

Forest Inventory ◽

Ecosystem Functioning ◽

Boreal Forests ◽

Vegetation Change ◽

National Forest Inventory ◽

Ground Vegetation ◽

National Forest ◽

Time Lags ◽

Forest Herbs ◽

Species Groups

The boreal forest floor vegetation is critical for ecosystem functioning and an important part of forest biodiversity. Given the ongoing global change, knowledge on broad-scale changes in the composition and abundance of different plant species and species groups is hence important for both forest conservation and management. Here, we analyse permanent plot data from the National Forest Inventory (NFI) on changes in the vegetation over a 10-year period in four regions of Sweden. To limit the direct and relatively well-known effects of forest management and associated succession, we only included mature forest stands not influenced by forestry during the 10 years between inventories, and focused on vegetation change mainly related to other factors. Results show strong decrease among many species and species groups. This includes dominant species such as Vaccinimum myrtillus and Deschampsia flexuosa as well as several forest herbs. The only species increasing are some mosses in the southern regions. Our data do not allow for a causal interpretation of the observed patterns. However, the changes probably result from latent succession in combination with climate change and nitrogen deposition, and with time lags complicating the interpretation of their relative importance. Regardless of the cause, the observed changes are on a magnitude that suggest impacts on ecosystem functioning and hence highlight the need for more experimental work.

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Will borealization of Arctic tundra herbivore communities be driven by climate warming or vegetation change?

Global Change Biology ◽

10.1111/gcb.15910 ◽

2021 ◽

Author(s):

James D. M. Speed ◽

Jesus Adrian Ballesteros Chimal ◽

Michael D. Martin ◽

Isabel C. Barrio ◽

Katariina E. M. Vuorinen ◽

...

Keyword(s):

Climate Warming ◽

Vegetation Change ◽

Arctic Tundra ◽

Herbivore Communities

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Response of Peatland CO2 and CH4 Fluxes to Experimental Warming and the Carbon Balance

Frontiers in Earth Science ◽

10.3389/feart.2021.631368 ◽

2021 ◽

Vol 9 ◽

Author(s):

Qian Li ◽

Sébastien Gogo ◽

Fabien Leroy ◽

Christophe Guimbaud ◽

Fatima Laggoun-Défarge

Keyword(s):

Climate Warming ◽

Vegetation Change ◽

Ecosystem Respiration ◽

Gross Primary Production ◽

Control Treatment ◽

Experimental Warming ◽

Short Term ◽

Annual Nee ◽

Abiotic And Biotic Factors ◽

And Control

The function of peatlands as a large carbon (C) reservoir results from the net C uptake under cold, wet, and acid environments. However, in the context of global warming, the balance between C input and release is expected to change, which may further alter the C sink of peatlands. To examine the response to climate warming of a temperate Sphagnum peatland which has been invaded by vascular plants, a mesocosm experiment was conducted with open top chambers (OTCs) to simulate a moderate temperature increase. Gross primary production (GPP), ecosystem respiration (ER), and methane (CH4) emissions were monitored for 2 years. The CO2 and CH4 fluxes were modeled by relating to abiotic and biotic factors, including temperature, water table depth (WTD), and vegetation, in order to calculate the annual C budget. Results showed that the annual cumulated GPP was significantly enhanced by the simulated warming (−602 compared to −501 gC m−2 yr−1 in OTC and control plots, respectively), mainly due to the increase of graminoid biomass by warming, while experimental warming had no significant effect on the annual ER and CH4 emissions (an output of 615 and 500 gC m−2 yr−1 for ER; 21 and 16 gC m−2 yr−1 for CH4 emissions in OTC and control plots, respectively). The annual NEE and C budget were not affected by the short-term experimental warming. The mesocosms under both treatments acted as a gaseous C source with 34 and 14 gC m−2 yr−1 output under OTC and control treatment, respectively. This C source was driven by the strong net carbon dioxide (CO2) release during a low WTD period in summer, as CH4 emissions only accounted for 0.9–2.2% of the total C fluxes. Our study identified the effect of moderate warming on the C fluxes, even on a short-term basis. Also, our findings highlighted that the response of C fluxes to warming largely depends on the WTD and vegetation composition. Thus, long-term monitoring of hydrology and vegetation change under climate warming is essential to examine their interactions in determining the C fluxes in peatlands.

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