Ecological impacts of wheat seeding after a Sierra Nevada wildfire

2004 ◽  
Vol 13 (1) ◽  
pp. 73 ◽  
Author(s):  
Jon E. Keeley
Keyword(s):  
Species Richness ◽  
Sierra Nevada ◽  
Ponderosa Pine ◽  
Seedling Recruitment ◽  
Vascular Plant ◽  
Ecological Impact ◽  
Ground Surface ◽  
Ecological Impacts ◽  
Total Species Richness ◽  
Giant Sequoia

The Highway Fire burned 1680 ha of mixed ponderosa pine–oak–chaparral in the newly created Giant Sequoia National Monument and the adjacent Sequoia National Forest of Fresno County, California in August 2001. The USDA Forest Service Burned Area Emergency Rehabilitation (BAER) program recommended that portions of the burned forest be seeded with a non-persistent variety of wheat at a density of 157 kg ha–1 (140 lb/ac). The present study compared the vascular plant diversity and cover in seeded and unseeded parts of this burn to evaluate the ecological impact of seeding an alien grass. In the first post-fire growing season, the natural regeneration of unseeded control sites averaged ~55% ground surface covered. Wheat seeding enhanced the ground cover, averaging 95% ground surface cover. Wheat was the dominant species on the seeded sites, comprising 67% of the total cover. Dominance–diversity curves were markedly affected by the seeding and indicated a disruption in the natural ecological structure of these communities. On seeded sites, wheat dominated and all other species were poorly represented whereas, on unseeded control sites, there was a more equitable distribution of species. Correlated with the wheat cover was a significant decrease in species richness at all scales examined. Total species richness was reduced from 152 species across all unseeded sites to 104 species on all seeded sites. Average species richness, at scales from 1 to 1000 m2, was 30–40% lower on seeded sites. Species most strongly inhibited were post-fire endemics whose lifecycle is restricted to immediate post-fire environments. Seeded sites had fewer alien species than unseeded sites; however, this may not have any lasting effect since other studies show the primary alien threat is not in the first post-fire year. Seeding was also associated with an order of magnitude drop in Pinus ponderosa seedling recruitment and, coupled with the massive thatch still remaining on the site, it is likely that recruitment will be inhibited in subsequent years.

scholarly journals Altitudinal Vascular Plant Richness and Climate Change in the Alpine Zone of the Lefka Ori, Crete

Diversity ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 22
Author(s):  
George Kazakis ◽  
Dany Ghosn ◽  
Ilektra Remoundou ◽  
Panagiotis Nyktas ◽  
Michael A. Talias ◽  
...  
Keyword(s):  
Climate Change ◽  
Species Richness ◽  
Spatial Scales ◽  
Vascular Plant ◽  
Monitoring Network ◽  
Mediterranean Area ◽  
Mean Annual Temperature ◽  
High Mountain ◽  
Species Loss ◽  
Total Species Richness

High mountain zones in the Mediterranean area are considered more vulnerable in comparison to lower altitudes zones. Lefka Ori massif, a global biodiversity hotspot on the island of Crete is part of the Global Observation Research Initiative in Alpine Environments (GLORIA) monitoring network. The paper examines species and vegetation changes with respect to climate and altitude over a seven-year period (2001–2008) at a range of spatial scales (10 m Summit Area Section-SAS, 5 m SAS, 1 m2) using the GLORIA protocol in a re-survey of four mountain summits (1664 m–2339 m). The absolute species loss between 2001–2008 was 4, among which were 2 endemics. At the scale of individual summits, the highest changes were recorded at the lower summits with absolute species loss 4 in both cases. Paired t-tests for the total species richness at 1 m2 between 2001–2008, showed no significant differences. No significant differences were found at the individual summit level neither at the 5 m SAS or the 10 m SAS. Time series analysis reveals that soil mean annual temperature is increasing at all summits. Linear regressions with the climatic variables show a positive effect on species richness at the 5 m and 10 m SAS as well as species changes at the 5 m SAS. In particular, June mean temperature has the highest predictive power for species changes at the 5 m SAS. Recorded changes in species richness point more towards fluctuations within a plant community’s normal range, although there seem to be more significant diversity changes in higher summits related to aspects. Our work provides additional evidence to assess the effects of climate change on plant diversity in Mediterranean mountains and particularly those of islands which remain understudied.

Are regional ecosystems compatible with floristic heterogeneity? A case study from Toohey Forest, south-east Queensland, Australia

2007 ◽  
Vol 13 (1) ◽  
pp. 47 ◽  
Author(s):  
Grant W. Wardell-Johnson ◽  
Ben E. Lawson ◽  
Robert H. Coutts
Keyword(s):  
Species Richness ◽  
Environmental Variables ◽  
A Priori ◽  
Vascular Plant ◽  
Vegetation Mapping ◽  
Heterogeneous Environments ◽  
Several Variables ◽  
Total Species Richness ◽  
Corymbia Citriodora ◽  
Mapping Scale

The recognition and effective portrayal of floristic heterogeneity is a complex issue for land classification. This study in Toohey Forest, south-east Queensland, examines the effects of mapping scale and environmental variables on a floristically heterogeneous area. Current Version 4.1 regional ecosystem mapping at 1: 1 00 000 scale maps Toohey Forest as a single regional ecosystem unit "12.11.5", described as an "open forest complex with Corymbia citriodora, Eucalyptus siderophloia, E. major on metamorphics ± interbedded volcanics". Plant taxa data from 50, 20 x 20 m sites comprising 247 native vascular plant taxa were collected, along with data for 17 environmental variables and 10 species richness categories. A priori site groupings of 1 :12 500 scale vegetation mapping and a geomorphic classifications of the area were examined using cluster analysis (UPGMA, Bray-Curtis Metric, β = –0.1) and ordination (SSH MDS). Biplots of several variables (shrub species richness, total species richness, per cent rock cover, CEC, carbon and phosphorus) were significantly (P < 0.05) correlated with the ordination axes derived from each of the two strata levels and the total taxa, for both geomorphological and vegetation mapping. Several variables (shrub, vine, woody and introduced species richness, and carbon, nitrogen, phosphorus, pH and CEC) varied significantly (P < 0.05) across both geomorphic categories and 1:12 500 scale vegetation community mapping. The ongoing reduction in regional ecosystem mapping scale, centred on the use of fine-scale geomorphology mapping, is likely to improve the representation of floristic patterns in heterogeneous environments.

scholarly journals Changes in plant diversity in a water-limited and isolated high-mountain range (Sierra Nevada, Spain)

Alpine Botany ◽  
2021 ◽  
Author(s):  
Andrea Lamprecht ◽  
Harald Pauli ◽  
Maria Rosa Fernández Calzado ◽  
Juan Lorite ◽  
Joaquín Molero Mesa ◽  
...  
Keyword(s):  
Species Richness ◽  
Snow Cover ◽  
Sierra Nevada ◽  
Plant Diversity ◽  
Endemic Species ◽  
Vascular Plant ◽  
Climate Change Impacts ◽  
Permanent Plots ◽  
High Mountain ◽  
Mountain Range

AbstractClimate change impacts are of a particular concern in small mountain ranges, where cold-adapted plant species have their optimum zone in the upper bioclimatic belts. This is commonly the case in Mediterranean mountains, which often harbour high numbers of endemic species, enhancing the risk of biodiversity losses. This study deals with shifts in vascular plant diversity in the upper zones of the Sierra Nevada, Spain, in relation with climatic parameters during the past two decades. We used vegetation data from permanent plots of three surveys of two GLORIA study regions, spanning a period of 18 years (2001–2019); ERA5 temperature and precipitation data; and snow cover durations, derived from on-site soil temperature data. Relationships between diversity patterns and climate factors were analysed using GLMMs. Species richness showed a decline between 2001 and 2008, and increased thereafter. Species cover increased slightly but significantly, although not for endemic species. While endemics underwent cover losses proportional to non-endemics, more widespread shrub species increased. Precipitation tended to increase during the last decade, after a downward trend since 1960. Precipitation was positively related to species richness, colonisation events, and cover, and negatively to disappearance events. Longer snow cover duration and rising temperatures were also related to increasing species numbers, but not to cover changes. The rapid biotic responses of Mediterranean alpine plants indicate a tight synchronisation with climate fluctuations, especially with water availability. Thus, it rather confirms concerns about biodiversity losses, if projections of increasing temperature in combination with decreasing precipitation hold true.

Wildland fire effects on understory plant communities in two fire-prone forests

2008 ◽  
Vol 38 (1) ◽  
pp. 133-142 ◽  
Author(s):  
Daniel C. Laughlin ◽  
Peter Z. Fulé
Keyword(s):  
Species Richness ◽  
Ponderosa Pine ◽  
Wildland Fire ◽  
Plant Cover ◽  
Plant Species Richness ◽  
Fire Effects ◽  
Surface Fire ◽  
Total Species Richness ◽  
Understory Plant ◽  
Understory Plant Communities

Our understanding of wildland fire effects on understory plant communities is limited because of a lack of repeated measurements before and after lightning-ignited fires. We examined vegetation responses to a surface fire in a ponderosa pine forest and a mixed-severity fire in a spruce–fir–aspen forest using before–after, control–impact (BACI) study designs. We hypothesized that the surface fire would stimulate plant species richness and minimally alter community composition, but that the mixed-severity fire would decrease richness and significantly alter composition. In ponderosa pine forests, total species richness and plant cover increased slightly because of annual and biennial forb and grass establishment in soils where duff layers were reduced by the surface fire. In spruce–fir–aspen forests, total species richness and plant cover were similar in burned and unburned forests after 2 years, although annual and biennial forbs and graminoids increased significantly in the burned area. Plant community composition was altered by both fires. Wildfires may indirectly influence the understory plant community through the mediating effects of overstory basal area and litter depth. Fire effects on plant species richness and cover were weaker than effects due to environmental factors. Managers should anticipate increases in both native and non-native ruderal species following landscape-scale fires.

scholarly journals The invasive herb Lupinus polyphyllus can reduce plant species richness independently of local invasion age

2021 ◽  
Author(s):  
Marju Prass ◽  
Satu Ramula ◽  
Miia Jauni ◽  
Heikki Setälä ◽  
D. Johan Kotze
Keyword(s):  
Species Richness ◽  
Plant Species ◽  
Plant Community ◽  
Plant Communities ◽  
Vascular Plant ◽  
Plant Species Richness ◽  
Ecological Impacts ◽  
Plant Community Composition ◽  
Lupinus Polyphyllus ◽  
Local Invasion

AbstractThe ecological impacts of invasive species may change or accumulate with time since local invasion, potentially inducing further changes in communities and the abiotic environment. Yet, time since invasion is rarely considered when investigating the ecological impacts of invasive non-native species. To examine the effect of time since invasion on the ecological impacts of Lupinus polyphyllus, a perennial nitrogen-fixing herb, we surveyed vascular plant communities in the presence and absence of L. polyphyllus in young, intermediate, and old semi-natural grassland sites (ca. 5, 10, 15 years representing both time since lupine invasion and plant community age). We analyzed vascular plant community composition, vascular plant species richness, and the cover of various ecological plant groups and L. polyphyllus. In contrast to our hypotheses, we found no change in the mean cover of L. polyphyllus (about 35%) with time since local invasion, and an ordination did not suggest marked changes in plant community composition. L. polyphyllus was associated with lower species richness in invaded plant communities but this effect did not change with time since invasion. Invaded plant communities were also associated with lower occurrence of generalist, oligotrophic (low-nutrient-adapted) and copiotrophic (nutrient-demanding) species but no temporal dynamics were detected. We conclude that even the intermediate cover of L. polyphyllus can reduce plant species richness, but the ecological impact caused by this invader might not dramatically change or accumulate with time since invasion.

scholarly journals Variation within the Bird Community of a Rehabilitated Urban Environment, Case of the Félix Houphouët-Boigny University Campus (Côte d'Ivoire)

2021 ◽  
Vol 9 (4) ◽  
Author(s):  
Ekoun Michael KONAN ◽  
Valérie Florence GUETONDE ◽  
Coffi Jean Magloire NIAMIEN ◽  
Kouassi Hilaire YAOKOKORE-BEIBRO
Keyword(s):  
Species Richness ◽  
Ecological Impact ◽  
Bird Species ◽  
Bird Community ◽  
University Campus ◽  
Significant Drop ◽  
Bubulcus Ibis ◽  
Total Species Richness ◽  
Ploceus Cucullatus ◽  
Total Species

In order to understand the ecological impact of the rehabilitation of the Félix Houphouët-Boigny University Campus on the bird community, a study was carried out over two months (October-November 2016). The ornithological inventory carried out by the IPA method in five different habitats identified on the campus gave a total species richness of 51 bird species of 41 genera, 27 families and 13 orders for 1374 birds, with H' = 2.93 and J = 0.74. Five species dominate the population (819 individuals, Fr = 59, 61%). These are Bubulcus ibis (9.32 %), Apus affinis (8.95 %), Corvus albus (19.94 %), Ploceus cucullatus (10.48 %), Lonchura cucullata (10.92 %). The most diversified habitat is the Habitations (26 bird species), while the most abundant is the Brush (416 individuals). Only seven species are common to all sampled habitats. Thus, 12 species observed on campus formerly could not be observed during the present study. Similarly, 18 species observed in this study were not observed in the previous study. The profound transformation of the environment following the rehabilitation has led to a slight increase in diversity but a significant drop in numbers. It is therefore important to better understand the different interactions between the components of the habitat and the various species involved. Such data would be crucial in urban planning policies.

scholarly journals Floodplain succession pattern along Budhi-Rapti River bank, Chitwan, Nepal

2018 ◽  
Vol 11 ◽  
pp. 12-26
Author(s):  
Dhiraj Chhetri Kunwar ◽  
Chitra Bahadur Baniya
Keyword(s):  
Species Richness ◽  
Vascular Plant ◽  
Significant Negative Correlation ◽  
Initial Position ◽  
Plant Succession ◽  
Systematic Sampling ◽  
Ageratum Conyzoides ◽  
River Bank ◽  
Total Species Richness ◽  
Time Substitution

 Riverine floodplain is one of the most productive lowland ecosystems in Nepal. However, floodplain ecology is less understood due to its fluctuation. Budhi-Rapti River in Chitwan, central Nepal formed a floodplain along the Khorsor zone of Barandabhar corridor. This study was carried out to understand the floodplain ecosystem development after plant succession. The space for time substitution method of vegetation sampling was adopted in order to sample the floodplain created at different chronosequence. The floodplain that lies perpendicular to and 200 m away from the Budhi-Rapti river was sampled. Systematic sampling was done along two parallel transects, almost 200 m apart from each other. Sampling along the transect started right after 200 m away from the Budhi-River bank. Initial position of these transects towards Budhi-Rapti river was believed to be the youngest floodplain, which slowly getting older after passing away from the river. Abundance of vascular plant species was recorded in sample plots of 20 × 20 m each subdivided equally into 4 subplots (each of 100 m2). Along each transect, vegetation data was recorded from a series of 20 plots, placed 50 m apart from each other. Successional scores were calculated and utilized as environmental variables after applying non-metric multi-dimensional scaling (NMDS) through metaMDS. Total and life form (herbs, shrubs and trees) richness patterns were calculated. Altogether, 158 species of vascular plants under 60 families and 136 genera were recorded. Gramineae was the richest family followed by Leguminosae, Asteraceae and Cyperaceae. Total species richness showed significant negative correlation with the NMDS1 and NMDS2, which justified a convergent pattern of succession. Herb, orchid and shrub species richness also showed significant declining pattern with NMDS1. Persicaria barbata, Parthenium hysterophorus, Ageratum conyzoides and Typha angustifolia were early succession indicator species; whereas Albizia lucidior, Miliusa velutina, Ficus hispida, Bauhinia purpurea and Brassaiopsis glomerulata were the late succession tree species. This study agreed with the convergent model of succession.Botanica Orientalis – Journal of Plant Science (2017) 11: 12–26

scholarly journals Influence of Ash Substrate Proximity on Growth and Survival of Planted Mixed-Conifer Seedlings

2009 ◽  
Vol 24 (3) ◽  
pp. 117-123 ◽  
Author(s):  
Robert A. York ◽  
Zachary Thomas ◽  
Joseph Restaino
Keyword(s):  
Sierra Nevada ◽  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Douglas Fir ◽  
Mixed Conifer ◽  
Basal Diameter ◽  
Growth And Survival ◽  
Sugar Pine ◽  
Giant Sequoia ◽  
Height Gain

Abstract To address uncertainty in the performance of seedlings planted in and around postburn substrates, we systematically planted seedlings in the center of, on the edge of, and outside ash substrate footprints following burning of logging residue piles and monitored growth and survival for a decade. Five species (Douglas-fir [Pseudotsuga menziesii], giant sequoia [Sequoiadendron giganteum], incense-cedar [Calocedrus decurrens], sugar pine [Pinus lambertiana], and ponderosa pine [Pinus ponderosa]) were planted in a regenerating mixed-conifer stand in the Sierra Nevada range of California. There was a positive effect of ash substrate proximity on growth that was immediate and persisted for 10 years for every species except incense-cedar. Seedlings planted in the centers of ash substrates consistently outgrew (in both height and basal diameter) seedlings that were planted either on the edges of or outside ash substrates. Douglas-fir had the greatest height gain (+47%), followed by giant sequoia (+28%), sugar pine (+23%), and ponderosa pine (+17%). Basal diameter differences were similar. No effect of ash proximity on survival was detected. Planting seedlings in the centers of ash substrates led to exceptionally larger trees by the time the stand had developed enough to apply a precommercial thin, a relevant milestone for managed stands.

scholarly journals Patterns in vascular plant species density in tall alpine herbfield along an increasing altitudinal gradient in an Australian alpine region

2009 ◽  
Vol 57 (3) ◽  
pp. 210 ◽  
Author(s):  
Catherine M. Pickering ◽  
Sarah Butler
Keyword(s):  
Species Richness ◽  
Plant Community ◽  
Vascular Plant ◽  
Alpine Region ◽  
Species Density ◽  
Location Data ◽  
Total Species Richness ◽  
Community Boundaries ◽  
Total Composition ◽  
Total Species

Patterns in species density and richness per altitudinal interval have been found when sampling across plant-community boundaries, including in the largest contiguous alpine area in Australia. To see if similar patterns occur within a single community, vascular-plant composition was systematically sampled with replicate nested quadrats of increasing size (0.01, 0.06, 0.25, 1.00, 4.00, 25.00, 49.00 and 100-m2 size) sampled from ~1850-m to 2100-m altitude in tall alpine herbfield, Australia. The only significant relationships with altitude were quadratic relationships for the density of herb and graminoid species, with peak density at middle altitudes and a linear decline in total species richness with altitude for 0.06-m2 quadrats. The composition of 100-m2 quadrats was unrelated to altitude when tested with analysis of similarity for total composition, whereas the relationship was significant for growth-forms and the origin (local endemics, Australia endemics and weeds) of species. Location data from this, and 11 other studies were used to compare the species richness of more of the flora (183 species) in 50-m altitudinal bands. There were significant quadratic relationships for total species richness and the number of herb and shrub species, with a peak in richness at ~2000 m. Therefore, altitude does affect species richness overall in this alpine region, although it has only a weak effect on species density within the most common plant community.

scholarly journals Effects of reindeer density on vascular plant diversity on North Scandinavian mountains

Rangifer ◽  
2005 ◽  
Vol 25 (1) ◽  
pp. 5 ◽  
Author(s):  
Johan Olofsson ◽  
Lauri Oksanen
Keyword(s):  
Species Richness ◽  
Vascular Plants ◽  
Vascular Plant ◽  
Detrended Correspondence Analysis ◽  
Diversity Indices ◽  
Rare Plants ◽  
Strong Impact ◽  
Total Species Richness ◽  
Species Lists ◽  
Mountain Chain

We studied the effects of reindeer grazing on species richness and diversity of vascular plants on dolomite influenced low alpine sites in the species rich northern part of the Scandes using 8 sites with different reindeer densities. Two sites were situated inside Malla Strict Nature Reserve, where reindeer grazing have been totally prohibited since 1981, and strongly restricted since 1950s. The six other sites were located in other species rich hotspot sites standardized to be as similar to the dolomite-influenced sites in Malla Strict Reserve as possible but varying in reindeer densities commonly found in the Fennoscandian mountain chain. Each site with a habitat complex especially rich in rare vascular plants (the Dryas heath – low herb meadow complex) was systematically sampled in four plots of 2 m x 10 m. The plots were divided to 20 squares of 1 m x 1 m, and complete species lists of vascular plants were compiled for each of the squares. The first DCA (detrended correspondence analysis) axis was strongly related to an index of reindeer grazing, indicating that grazing has a strong impact on the composition of the vegetation. None of the characteristics indices of biodiversity (species richness, evenness or Shannon-Wiener H’) was correlated with reindeer density. The local abundances of categories consisting of relatively rare plants (Ca favored plants and red listed plants of Finland) showed significant, positive correlation with the intensity of reindeer grazing. We conclude that even though the density of reindeer has no influence on the total species richness or diversity of vascular plants, reindeer may still be important for regional biodiversity as it seems to favour rare and threatened plants. Moreover, our results imply that standard diversity indices may have limited value in the context of conservation biology, as these indices are equally influenced by rarities and by trivial species.Abstract in Swedish / Sammandrag: Vi studerade hur renbete påverkar kärlväxtflorans artrikedom och diversitet på dolomitpåverkade lågalpina lokaler i de artrikaste delarna av norra Fennoskandien. Vi inventerade 8 lokaler med olika rentätheter. Två lokaler ligger inom Malla Nationalpark, där renar har varit förbjudna sedan 1981 och starkt begränsade sedan 1950-talet. De sex andra lokalerna ligger i andra artrika områden med samma dolomitdominerade berggrund, men är betade av renar. Rentätheterna vid de studerade lokalerna varierar från helt obefintligt till bland de högsta rentätheter man kan finna i Fennoskandien. Inventeringen utfördes genom att systematiskt undersöka fyra 2 m x 10 m stora ytor i varje lokal i en habitattyp som är speciellt rik i ovanliga kärlväxter (fjällsippehed-lågörtsäng komplex). Varje yta delades upp i 20 småytor (1 m x 1 m), och en total artlista upprättades för var och en av dessa småytor. Den första axeln i DCA (detrended correspondence analyses) analysen korrelerade med rentätheten. Det visar att renar påverkar sammansättningen av växtsamhället. Ingen av de vanliga måtten på biodiversitet (artrikedom eller Shannon-Wiener diversitetsindex) var korrelerade med rentätheten. Trots detta, var tätheterna av Ca-gynnade växter och arter rödlistade i Finland positivt korrelerade med rentätheten. Trots att renarna inte påverkade totala artrikedommen, kan de vara betydelsefulla för regionala biodiversiteten eftersom de gynnar ovanliga och hotade arter. De vanliga måtten på biodiversitet har begränsat värde för bevarandebiologiska frågeställningar, eftersom de är lika känsliga för ovanliga och vanliga arter.

Sign in / Sign up

Export Citation Format

Share Document