Total Vegetation Research Articles

Biomass carbon stocks of different land use management in the forest vegetative zone of Nigeria

Land use/land cover change tends to play a more critical role in controlling CO2 emissions and annual storage. Despite the fact that the majority of the deforestation and forest degradation and consequent emissions have been occurring in tropical developing countries, little or no direct quantifications of the effects of land use change on the Carbon pools of these land use systems have been done. Taking into consideration four (4) land use systems in Ekiti State, South-western Nigeria, we quantified the magnitude of biomass and biomass carbon stocks in the following carbon pools: trees, non-woody vegetation, litter, coarse woody debris and roots. Total biomass carbon stocks of the different land use land cover types decreased in the order: Natural forests (NF) (155.61 Mg C ha-1) > Plantations (TP) (80.37 Mg C ha−1) > Woodlands (WD) (41.17 Mg C ha−1) > Croplands (CP) (35.33 Mg C ha−1). Approximately 50% of the total vegetation carbon stocks are contained in natural forests in the study. Estimation of C stocks in Necromass pools is important for carbon quantification most especially in the croplands and agroforestry ecosystems. Natural forest of all the land use types has the greatest biomass carbon storage potential with an estimated standing stock of 155.61 Mg C ha−1 while cropland has the least carbon storage with a measured standing stock of 35.33 Mg C ha−1. We observed a reduction of 120.28 Mg C ha−1 and 75.24 Mg C ha−1 of the total biomass carbon stocks as a result of a change of natural forest to croplands and plantations, suggesting important C loses in the ecosystems. Improving our knowledge of terrestrial sources and sinks of CO2 and other greenhouse gases (GHGs), and their spatiotemporal variability is a key action to better understand and predict the global change and enhance human capacity to undertake mitigation and adaptation strategies.

Effects of soil properties, topography and landform on the understory biomass of a pine forest in a subtropical hilly region

Soil conservation will remain an essential subject for forest in slope land. However, the interactions between soil, vegetation and complex topography are not fully understood. To address this concern, field studies were performed in a typical small watershed in the subtropical hilly red soil region of China. This site covers an area of approximately 3.2 ha, and the mean slope steepness of the land is 15°. Soil properties (including available and total N, P, K, soil organic carbon (SOC), CEC, soil texture), understory vegetation biomass and diversity index on different slopes (different slope steepness, slope aspects, and slope positions) were measured. Meanwhile, interrelationships between understory vegetation biomass and soil properties, slope steepness and altitude were evaluated via redundancy analysis. The study results showed that the soil nutrients and SOC contents were greater in the down-slope and north and west slopes. And the soil properties displayed high spatial heterogeneity and had semi-variance structure, which were mainly derived from random factors. Due to obvious erosion characteristics and the negative correlations between soil properties and slope positions, we suspected that soil erosion was the primary random factor. In addition, the mean total understory vegetation biomass in the pine forest was 283.58 g m−2 (ranging from 66.60 to 573.79), and higher vegetation biomass was found in down-slope and north and west slopes. Further analyses indicated that topography (slope steepness and altitude) and soil properties combined contributed to 58.7% of the variations in the understory biomass, and they individually had a contribution of 17.3% and 41.4%, respectively. Moreover, altitude (height of slope positions) alone explained 15.9% of the variation of the vegetation biomass. This study indicated that soil properties, which were highly affected by slope aspect and slope position, were the most important factor in influencing understory vegetation biomass in subtropical pine forest. Slope position also had a tremendous direct influence on soil vegetation. Controlling understory soil erosion is essential for conservation of pine forest land in subtropical China.

Landscape Ecology in a Watershed of the Ocoy River, Western Parana State, Brazil

ABSTRACT This study evaluated the landscape structure of a watershed located in a region considered strategic for the implementation of the Parana River Biodiversity Corridor. Based on land-use/land-cover mapping, four different scenarios were generated: 1) real situation, 2) considering the edge effect, 3) without Permanent Preservation Areas (APPs), and 4) with restoration of the riparian APPs. Different landscape metrics were calculated for each scenario. In scenario 2, only 28% of the total natural vegetation cover remained as core areas. In scenario 3, there was a considerable increase in forest fragmentation. In scenario 4, an expressive increase in landscape connectivity was promoted. In conclusion, a relatively small increase in natural vegetation cover can promote considerable increase in landscape connectivity and restoration of the riparian APPs in watersheds of the region should be considered as a priority action for the implementation of the Parana River Biodiversity Corridor.

Increases in thermophilus plants in an arid alpine community in response to experimental warming

ABSTRACTA warming climate has been shown to drive thermophilization—shifts in species abundance toward those adapted to warm and dry conditions. The community dynamics shaping this process have been proposed to vary between temperature-limited alpine plant communities and those that are both temperature and moisture limited. In nine sites across the xeric alpine zone in the White Mountains, California, USA, we experimentally increased summertime temperature and precipitation for three seasons and quantified community responses with a climatic niche analysis. We asked if thermophilization occurred in response to experimental heating, and if this effect was ameliorated by experimental watering. Under experimentally warmer conditions, we found no change in the mean community-weighted climatic niche (CCN); however, thermophilization of this community was observed based on a shift in the seventy-fifth percentile of the CCN and an increase in the proportional abundance of the hottest, driest adapted species. In addition, total vegetation abundance increased and species richness decreased with heating. Experimental watering did not ameliorate these effects of heating. Together, these results suggest that warming in arid alpine areas may result in less diverse plant communities dominated by hot, dry associated species, although short-term responses may be limited because of community lags.

Influence of climate, post‐treatment weather extremes, and soil factors on vegetation recovery after restoration treatments in the southwestern US

AbstractAimsUnderstanding the conditions associated with dryland vegetation recovery after restoration treatments is challenging due to a lack of monitoring data and high environmental variability over time and space. Tracking recovery trajectories with satellite‐based vegetation indices can strengthen predictions of restoration outcomes across broad areas with varying environmental conditions.LocationSouthwestern United States.MethodsWe quantified the recovery trajectories of spring and summer soil‐adjusted total vegetation index (SATVI) for 5–10 year periods following post‐wildfire seeding or prescribed burns for 241 treatment sites and related SATVI to ground‐based vegetation cover. We modeled SATVI based on time since treatment, yearly temperature and precipitation, weather extremes following treatment, soil available water capacity, invasive species presence, and treatment type. We also tested for the effects of environmental variables on trajectories, by examining interactions with years post‐treatment.ResultsGround‐based vegetation cover and SATVI were highly correlated. Most treatment sites had positive recovery rates for spring (82%) and summer (85%) SATVI. Several environmental variables affected vegetation recovery trajectories as indicated by interactions with time since treatment. Yearly warm season precipitation had a positive effect on SATVI recovery that increased over time, whereas the positive effect of extreme high warm season precipitation following treatment decreased over time for both seasons of vegetation measurements. For spring SATVI, the positive effect of cool season yearly precipitation increased over time while the negative effect of extreme high temperatures following treatment became more negative over time. Invasive species presence led to higher spring, but not summer, SATVI.ConclusionsSatellite‐based remote sensing is a promising tool to assess vegetation recovery following restoration treatments, particularly when it is combined with ground‐based monitoring. Our results suggest that weather extremes following restoration treatments can affect vegetation recovery trajectories and may be considered in management decisions such as the timing of restoration treatments.

Combining optimization and simulation modelling to measure the cumulative impacts of prescribed fire and wildfire on vegetation species diversity

Abstract Growth‐stage optimization (GSO) offers a new approach to biodiversity conservation in fire‐prone regions by estimating the optimal distribution of vegetation growth stages that maximize a species diversity index. This optimal growth‐stage structure provides managers an operational goal explicitly linked to a positive conservation outcome but does not define the fire regime needed to achieve it. We paired GSO with LANDIS II, a landscape succession and disturbance simulation model, to (a) estimate the optimal growth‐stage structure that maximized vegetation diversity in a south‐east Australian heathy woodland, (b) define the fire regime needed to achieve it, and (c) determine the cumulative effects of different fire‐regime scenarios on vegetation diversity over a 60‐year period. Scenarios included 0%, 2%, 5%, and 10% of the landscape burnt per year by prescribed fire only, or in combination with three alternative wildfire regimes. Furthermore, we investigated the differences in the optimal growth‐stage structure relating to above‐ground, soil seedbank, and total (above and soil seedbank) diversity datasets. The growth‐stage structure that maximized total vegetation diversity comprised approximately even proportions of all stages. In contrast, separately analysed above‐ground and soil seedbank data resulted in a greater proportion of younger and older growth‐stages, respectively. Scenarios including 5% prescribed burning per year (with and without wildfire) resulted in diversity values within 1.5% of the theoretical maximum value. Scenarios including 2% and 10% prescribed fire resulted in diversity values 8%–12% and 1.5%–5% lower than the maximum, respectively. Scenarios without prescribed fire caused diversity to fall 30%–70%. Trends across the 60 years showed that wildfire depressed diversity and subsequent prescribed fire drove recovery within 15 years. The largest threat to vegetation diversity was the absence of fire. Synthesis and applications. Combining growth‐stage optimization and simulation modelling is a powerful way of defining a conservation‐based fire management goal and identifying the prescribed fire regime needed to achieve it. We demonstrated that vegetation diversity in heathy woodland was increased by prescribed fire, with and without the cumulative effect of wildfire, and declined sharply when fire was excluded. Our method provides a flexible platform for developing long‐term fire management strategies that seek to balance human safety and biodiversity conservation. Including both plants and animals in GSO will help land managers meet the needs of multiple taxa.

Small-Scale Soil Microbial Community Heterogeneity Linked to Landform Historical Events on King George Island, Maritime Antarctica.

Although research on microbial biogeography has made great progress in the past decade, distributions of terrestrial microbial communities in extreme environments such as Antarctica are not well understood. In addition, knowledge of whether and how historical contingencies affect microbial distributions at small spatial scales is lacking. Here, we analyzed soil-borne microbial (bacterial, archaeal, and fungal) communities in 12 quadrat plots around the Fildes Region of King George Island, maritime Antarctica, and the communities were divided into two groups according to the soil elemental compositions and environmental attributes of Holocene raised beach and Tertiary volcanic stratigraphy. Prokaryotic communities of the two groups were well separated; the prokaryotic data were primarily correlated with soil elemental compositions and were secondly correlated with environmental attributes (e.g., soil pH, total organic carbon, NO3-, and vegetation coverage; Pearson test, r = 0.59 vs. 0.52, both P < 0.01). The relatively high abundance of P, S, Cl, and Br in Group 1 (Holocene raised beach site) was likely due to landform uplift. Lithophile-elements (Si, Al, Ca, Sr, Ti, V, and Fe) correlated with prokaryotic communities in Group 2 may have originated from weathering of Tertiary volcanic rock. No significant correlations were found between the fungal community distribution and both the soil elemental composition and environmental attributes in this study; however, Monte Carlo tests revealed that elements Sr and Ti, soil pH, sampling altitude, and moss and lichen species numbers had significant impacts on fungal communities. The elements and nutrients accumulated during the formation of different landforms influenced the development of soils, plant growth, and microbial communities, and this resulted in small-scale spatially heterogeneous biological distributions. These findings provide new evidence that geological evolutionary processes in the Fildes Region were crucial to its microbial community development, and the results highlight that microbial distribution patterns are the legacies of historical events at this small spatial scale. Based on this study, the ice-free regions in maritime Antarctica represent suitable research sites for studying the influence of geomorphological features on microbial distributions, and we envision the possibility of a site-specific landform assignment through the analysis of the soil prokaryotic community structure.

Spatial imbalance and changes in supply and demand of ecosystem services in China

Human activities and regional land development have caused intense interference to ecosystems. With rapid development of economy and urgent needs of life quality improvements in China, sustainable ecosystem management is crucial for national ecological civilization construction. However, few studies have focused on supply-demand patterns of ecosystem services on a national scale in China. The aim of this study was to analyze the spatial-temporal patterns and changes in the supply-demand of ecosystem services and to explore their interactive relationship in the context of economic development and urbanization drivers. The ecosystem services provision index (ESPI) and land development index (LDI) were proposed to indicate the supply and demand for ecosystem services. The results indicated that the Low supply-High demand (L-H) pattern accounted for 3.27% of the total land area in China and was mainly concentrated in developed regions and some capital cities, where 28.95% of the total population and 51.93% of the country's GDP was generated in 2015. The spatial imbalance in the supply-demand of ecosystem services was obvious. From 2000 to 2015, the imbalance was shrinking, and regions with negative changes in supply-demand patterns were declining. During 2000–2008, there was an obvious transformation from Low supply-Low demand (L-L) to High supply-Low demand (H-L), which accounted for 12.44% of the total land area due to Grain for Green and other ecological protection policies. The proportion of ecological land to total land area, vegetation cover and elevation were significantly correlated with the supply of ecosystem services. In the meantime, ESPI was negatively correlated with LDI in most regions in China. There were also regional differences in their relationships. The rapid economic growth and the intensive land development resulted in a more significant decrease in ESPI in the developed regions than that in the undeveloped North and Northeast China. The results of this study could contribute to sustainable ecosystem management and decision-making for Chinese ecological civilization construction.

Biomass and carbon budgeting of land use types along elevation gradient in Central Himalayas

Biomass of vegetation is a crucial variable for understanding the potential future changes of the climate system. In the present study dominant land use types i.e. agroforestry (AF), banjoak forest (BF), chirpine forest (CF), mixed forest (MF) and grasslands (GL) of Himalayan region was investigated for biomass production and carbon stock budgeting in vegetation as well as in soil. Among land use type's highest aboveground biomass was recorded in banjoak forest (BF), 0.69%, 9.42% and 40.16% more than chirpine forest (CF), mixed forest (MF) and agroforestry (AF). However it was more than 16 times higher than grasslands (GL). Herbage and/or crops aboveground biomass was 3.73%, 4.05%, 4.42% and 29.34% of the aboveground biomass of trees in BF, CF, MF and AF. Herbage aboveground biomass was 76.01% of total aboveground biomass in grasslands. Our results revealed that in AF crops biomass accounted for 19.41–26.60% and trees contributed 73.40–80.59% biomass in total biomass of land use. Likewise, similar contributions were recorded for belowground biomass and total biomass in land uses. Irrespective of land use types along elevation the total biomass including aboveground and belowground biomass significantly (P < 0.01) increased. Among land use types and along the elevation similar trend was recorded for vegetation carbon stock as it is the manifestation of biomass. Soil carbon density differed significantly in land use types with highest in BF and increased significantly along the elevation with highest at elevation E5. Forest land uses stored 26.22% and 53.79% more total (vegetation + soil) carbon in than agroforestry and grasslands. The difference in carbon storage among land use types can be related to land use type, vegetation composition, their structural and functional characteristics viz., density, age and soil type. Thus, tree based land use types are more efficient for biomass production and carbon storage in changing climatic pattern.

Long-term impacts of livestock grazing and browsing in the Succulent Karoo: a 20-year study of vegetation change under different grazing regimes in Namaqualand

This study used a fence-line contrast approach to investigate the long-term impact of high grazing pressure on the vegetation at a site in Namaqualand, South Africa. Forty pairs of permanently marked plots were surveyed in 1996, 2006 and 2016. The main objective was to investigate changes in the vegetation structure and species composition between the near-continuously grazed communal rangelands and the relatively lightly grazed commercial rangelands over the 20-year period. The results showed a decline in total vegetation cover in both commercial and communal rangelands in 2016 relative to the two earlier sampling periods. This can be attributed to the low rainfall in 2016 and was due largely to a reduction in annual plant cover, especially on the communal rangeland. Perennial shrub species provide a fodder bank that can be utilised by livestock in times of drought and can buffer short-term deficits in forage supply. However, the annuals that dominate the vegetation of the communal rangeland do not form such fodder banks and consequently do not have the same multi-year buffering capacity as perennial shrubs. This provides the mechanism whereby long-term continuous grazing decreases resilience to rainfall fluctuations and increases livestock variability, thereby promoting non-equilibrium-type dynamics in the system.

Longer-Term Evaluation of Sagebrush Restoration After Juniper Control and Herbaceous Vegetation Trade-offs

Degradation of shrublands around the world from altered fire regimes, overutilization, and anthropogenic disturbance has resulted in a widespread need for shrub restoration. In western North America, reestablishment of mountain big sagebrush (Artemisia tridentata Nutt. ssp. vaseyana [Rydb.] Beetle) is needed to restore ecosystem services and function. Western juniper (Juniperus occidentalis ssp. occidentalis Hook) encroachment is a serious threat to mountain big sagebrush communities in the northern Great Basin and Columbia Plateau. Juniper trees can be controlled with fire; however, sagebrush recovery may be slow, especially if encroachment largely eliminated sagebrush before juniper control. Short-term studies have suggested that seeding mountain big sagebrush after juniper control may accelerate sagebrush recovery. Longer-term information is lacking on how sagebrush recovery progresses and if there are trade-offs with herbaceous vegetation. We compared seeding and not seeding mountain big sagebrush after juniper control (partial cutting followed with burning) in fully developed juniper woodlands (i.e., sagebrush had been largely excluded) at five sites, 7 and 8 yr after seeding. Sagebrush cover averaged ~30% in sagebrush seeded plots compared with ~1% in unseeded plots 8 yr after seeding, thus suggesting that sagebrush recovery may be slow without seeding after juniper control. Total herbaceous vegetation, perennial grass, and annual forb cover was less where sagebrush was seeded. Thus, there is a trade-off with herbaceous vegetation with seeding sagebrush. Our results suggest that seeding sagebrush after juniper control can accelerate the recovery of sagebrush habitat characteristics, which is important for sagebrush-associated wildlife. We suggest land manager and restoration practitioners consider seeding sagebrush and possibly other shrubs after controlling encroaching trees where residual shrubs are lacking after control.

Driving Factors That Reduce Soil Carbon, Sugar, and Microbial Biomass in Degraded Alpine Grasslands

Soil carbon and sugars play key roles in carbon (C) cycling in grassland ecosystems. However, little is known about their changes in quantity and composition in degraded alpine meadows in the Tibetan plateau. We compared vegetation C density, soil organic carbon (SOC) density, and soil sugars in nondegraded (ND), degraded (DA; following artificial restoration), and extremely degraded (ED) grasslands and analyzed the relation among these parameters by redundancy analysis (RDA) and structural equation models (SEMs). Belowground biomass, soil microbial biomass C, soil microbial biomass nitrogen (N), belowground biomass C density, SOC density, and soil sugars were lower in DA and ED grasslands than in ND grasslands. In addition, the ratio of belowground biomass to aboveground biomass (BAR) decreased with an increase in degradation. The ratio of belowground biomass to aboveground biomass was identified as the main indirect driving force of ecosystem C density by affecting total vegetation C and SOC densities. Soil dissolved organic carbon (DOC), microbial biomass carbon (SMBC), neutral sugars (NS), and total nitrogen (TN) were identified as main direct driving forces. The ratio of belowground biomass to aboveground biomass altered DOC, SMBC, NS, and TN and, consequently, was the primary driving force for the alpine meadows’ ecosystem C density. It was concluded that land management in alpine meadows should include practices that maintain a relatively high BAR in order to curb degradation and increase ecosystem C density.

Forest carbon storage in Guizhou Province based on field measurement dataset

Accurate estimation of forest carbon storage is crucial in understanding global and regional carbon cycles and projecting future ecological and economic scenarios. Guizhou is the largest karst landform province in China; 61.9% of its land area is characterized as karst. However, monitoring its field biomass and carbon storage is difficult. This study synthesized and analyzed a comprehensive database of direct field observations of forest vegetation and soil carbon storage in Guizhou Province by using data from existing literature. The total vegetation carbon storage in Guizhou Province was 488.170 TgC, the average vegetation carbon density (VCD) was 27.866 MgC hm−2, the total amount of soil organic carbon (SOC) (20 cm) was 1017.364 TgC, and the average SOC density was 58.074 MgC hm−2. Among all vegetation types, needleleaf forest had the highest vegetation carbon stocks, and scrub presented the highest SOC storage. The vegetation and SOC storage values of the karst landform were 282.352 and 614.825 TgC, respectively, which were higher than those of the non-karst landform. VCD was concentrated at 10–40 MgC hm−2, and SOC density was concentrated at 40–60, 60–80, and 80–100 MgC hm−2. This comprehensive regional data synthesis and analysis based on direct field measurement of vegetation and soil will improve our understanding of the forest carbon cycle in karst landforms under a changing climate.

Advanced land observing satellite data to identify ground vegetation in a juniper forest, northeast Iran

Juniperus excelsa subsp. polycarpos, (Persian juniper), is found in northeast Iran. In this study, the relationship between ground cover and vegetation indices have been investigated using remote sensing data for a Persian juniper forest. Multispectral data were analyzed based on the Advanced Visible and Near Infrared Radiometer type 2 and panchromatic data obtained by the Panchromatic Remote-sensing Instrument for Stereo Mapping sensors, both on board the advanced land observing satellite (ALOS). The ground cover was calculated using field survey data from 25 sub-sample plots and the vegetation indices were derived with 5 × 5 maximum filtering algorithm from ALOS data. R2 values were calculated for the normalized difference vegetation index (NDVI) and various soil-adjusted vegetation indices (SAVI) with soil-brightness-dependent correction factors equal to 1 and 0.5, a modified SAVI (MSAVI) and an optimized SAVI (OSAVI). R2 values for the NDVI, MSAVI, OSAVI, SAVI (1), and SAVI (0.5) were 0.566, 0.545, 0.619, 0.603, and 0.607, respectively. Total ratio vegetation index for arid and semi-arid regions based on spectral wavelengths of ALOS data with an R2 value 0.633 was considered. Results of the current study will be useful for forest inventories in arid and semi-arid regions in addition to assisting decision-making for natural resource managers.

Influence analysis of artificial ecological water transport on the spatiotemporal variations in vegetation in Qingtu Lake

As an ecological barrier between the Badain Jaran Desert and Tengger Desert, Qingtu Lake plays an important role in maintaining the local ecological environment. Since 2010, annual artificial water transport to Qingtu Lake has caused changes in local vegetation communities, which is of great ecological significance for promoting regional vegetation restoration. In this study, Landsat satellite remote sensing images from 2010 to 2017 were used to compare the water surface area, vegetation coverage, and spatial patterns of Phragmites australis communities before and after ecological water transport. The results showed that the water surface area increased rapidly until 2016, and the growth rate of the last two years decreased. There was a slight increase in total regional vegetation coverage, which mainly occurred in the water area due to the substantial growth in P. australis. Therefore, artificial ecological water transport promoted the growth in vegetation around the lake, especially the aquatic vegetation, such as P. australis. However, the original desert vegetation in the study area may have been reduced due to submergence.

Aquatic vegetation community structure response to hydrilla management with triploid grass carp, herbicide, and native vegetation planting

Schad AN, Dick GO. Aquatic vegetation community structure response to hydrilla management with triploid grass carp, herbicide, and native vegetation planting. Lake Reserve Manage. 34:417–425.To aid conservation managers conducting hydrilla (Hydrilla verticillata (L.f.) Royle) management, we evaluated changes in aquatic vegetation community structure and dominance in dioecious hydrilla-infested ponds by applying several management tools and monitoring vegetation changes on an annual basis over a 4 yr period. The study was conducted in fully vegetated (dioecious hydrilla and native macrophytes) 0.3 ha mesocosm ponds using 4 levels of triploid grass carp (Ctenopharyngodon idella Valenciennes) stocking densities (0–129 per vegetated hectare), a one-time second-year herbicide treatment to reduce standing biomass of hydrilla and other submersed aquatic vegetation (SAV), and native plantings to provide the basis for replacing hydrilla as it was controlled. Grass carp stocking density had an inverse relationship with coverage of total vegetation, hydrilla, volunteer SAV, and volunteer emergents. All vegetation categories recovered from the one-time herbicide application, although this was suppressed by higher densities of grass carp. Grass carp did not significantly affect planted growth forms (SAV, floating-leaved, and emergent), with increases in mean coverage in all treatments through time, although coverage was lowest at the highest grass carp density. Vegetation dominance shifted from hydrilla to native in both control and low grass carp density treatments, with most SAV eliminated from treatments stocked with more than 72 per hectare.

Evaluating the impact of future actions in minimizing vegetation loss from land conversion in the Brazilian Cerrado under climate change

The global network of protected areas (PAs) is systematically biased towards remote and unproductive places. Consequently, the processes threatening biodiversity are not halted and conservation impact—defined as the beneficial environmental outcomes arising from protection relative to the counterfactual of no intervention—is smaller than previously thought. Yet, many conservation plans still target species’ representation, which can fail to lead to impact by not considering the threats they face, such as land conversion and climate change. Here we aimed to identify spatial conservation priorities that minimize the risk of land conversion, while retaining sites with high value for threatened plants at risk from climate change in the Brazilian Cerrado. We compared a method of sequential implementation of conservation actions to a static strategy applied at one time-step. For both schedules of conservation actions, we applied two methods for setting priorities: (i) minimizing expected habitat conversion and prioritizing valuable sites for threatened plants (therefore maximizing conservation impact), and (ii) prioritizing sites based only on their value for threatened plants, regardless of their vulnerability to land conversion (therefore maximizing representation). We found that scenarios aimed at maximizing conservation impact reduced total vegetation loss, while still covering large proportions of species’ ranges inside PAs and priority sites. Given that planning to avoid vegetation loss provided these benefits, vegetation information could represent a reliable surrogate for overall biodiversity. Besides allowing for the achievement of two distinct goals (representation and impact), the impact strategies also present great potential for implementation, especially under current conservation policies.

Is penetration of non-psammophytes an underestimated threat to sand dunes? - a case study from western Pontic coast

The aim of this study was to identify how far the different dune types from one of the largest dune complexes at the Bulgarian Black Sea Coast are affected by the penetration of non-psammophytes and if there is an upward trend in their number. We studied the Kamchia dune system during 2013–2015. Vegetation was sampled at 162 plots along 12 transects systematically situated to cover three different habitats: embryonic, white and grey dunes. All vascular plants as well as cover percentage of each species and total vegetation cover were registered within each plot. The overall species list of the different dune types was additionally completed for the whole study area. A total 207 plant species were registered. They were classified into five groups as follows: psammophytes – 38, weeds and ruderals – 36, plants typical of grasslands and shrublands – 95, plants typical of forests – 18 and alien (including invasive) species – 20. Number and cover of defined groups were calculated in respect to their distribution in different dune habitats. Results show that grey dunes contain the highest percentage of non-psammophytic plants, which decrease towards white and embryonic dunes. The studied coastal area is still less influenced by non-psammophytes. It represents an example of a Bulgarian Black Sea coastal dune complex that is relatively unaffected by urbanization. The high floristic and habitat diversity deserve further effective protection.

Grazing and spring snow counteract the effects of warming on an alpine plant community in Tibet through effects on the dominant species

Although studies have investigated the independent effects of warming, snow, and grazing on alpine plant community properties – including plant species richness, evenness, and diversity - the interactive effects of these climate and grazing factors have not been addressed experimentally in cold systems. We investigate the effects of these climate change and grazing factors using 5 years of data collected from a relatively long-term (2009–2015), fully-factorial field experiment in an alpine meadow ecosystem on the central Tibetan Plateau. Specifically, we investigate: 1) how experimental warming, spring snow addition, and yak grazing independently and interactively affect plant community properties, including diversity metrics and relative contributions of different plant life forms to the total plant cover, and 2) how the changes in plant community properties are associated with the proportional cover of the dominant plant species, Kobresia pygmaea within the total vegetation cover. We found that warming reduced species richness and increased species evenness and the proportional cover of shrubs within the total vegetation cover. Snow addition also increased species evenness. Grazing increased the proportional cover of K. pygmaea within the total vegetation cover, while decreasing that of grasses. Grazing also counteracted warming-induced increases in shrubs. Treatment-induced changes in K. pygmaea cover were strongly correlated with the indices of plant community properties and were generally in the opposite direction of changes in species evenness and diversity. We conclude that the projected increases in spring snowstorms and maintaining moderate levels of grazing can counteract some warming effects on the plant community. Moreover, the performance of the dominant species can regulate plant community responses to climate change and livestock grazing on the central Tibetan Plateau.

Giant stem rosettes have strong facilitation effects on alpine plant communities in the tropical Andes

ABSTRACTBackground: Giant rosettes constitute one of the most distinctive growth-forms in tropical alpine ecosystems. However, their interactions with other plant species remain unexplored in high Andean páramos.Aims: Quantify the effect of a dominant rosette (Coespeletia timotensis) on soil and microclimatic conditions and relate the impacts to plant community structure.Methods: We analysed topsoil temperatures, soil organic matter (SOM) and plant species cover in areas adjacent to C. timotensis and paired areas outside, at three sites (4250–4360 m a.s.l.) in La Culata National Park, Venezuela. Species richness, total vegetation cover and percent cover of each species near and away from the rosettes were compared.Results: Topsoil temperature amplitudes were lower and SOM greater near C. timotensis stems, compared to areas away from them. C. timotensis had a consistent positive effect on species richness, vegetation cover and the cover of many abundant species (including cushions and herbs).Conclusions: The facilitation effects of C. timotensis on abiotic conditions and community structure indicate they play a key role as nurse plants, pointing to giant rosettes as foundation species for the maintenance of plant diversity in the alpine tropics.