Impacts of Buffelgrass (Pennisetum ciliare) on a Forb Community in South Texas

2009 ◽  
Vol 2 (2) ◽  
pp. 130-140 ◽  
Author(s):  
Joseph P. Sands ◽  
Leonard A. Brennan ◽  
Fidel Hernández ◽  
William P. Kuvlesky ◽  
James F. Gallagher ◽  
...  

AbstractSince the 1950s, many south Texas rangelands have been seeded with buffelgrass, a perennial C4 bunchgrass native to Africa that is believed to contribute to reductions in biodiversity. Forb species represent a critical habitat component throughout the breeding period for many wildlife species as seed (summer to fall), as green vegetative material (spring to summer), and as habitat for arthropods (spring to summer). Reductions in richness and diversity of crucial ecosystem components such as forbs and arthropods have large implications for grassland birds and other wildlife. We sampled annual and perennial forbs within 1-m2 quadrats on 15 study plots (1 ha; n = 20 quadrats/plot) at Chaparral Wildlife Management Area, in LaSalle and Dimmit counties, Texas, during 2005 and 2006. Study plots were divided into five light-buffelgrass plots (0 to 5% buffelgrass canopy coverage), five moderate-buffelgrass plots (5 to 25% buffelgrass canopy coverage), and five heavy-buffelgrass plots (> 25% buffelgrass canopy coverage). Buffelgrass in study plots was composed of naturalized plants, and was not deliberately planted. During 2005 we observed that plots with > 25% buffelgrass had a 73% reduction in forb canopy of native species, a 64% reduction in native forb species richness, and a 77% reduction in native forb stem density compared to plots with 0 to 5% buffelgrass. These trends in native forb reduction (−79% native forb canopy, −65% forb species richness, −80% forb stem density) were nearly identical in 2006, even with greatly reduced rainfall. Simple linear regression revealed negative relationships between buffelgrass cover, total exotic grass cover (buffelgrass and Lehmann lovegrass), and total grass cover and the richness, coverage, and density of forbs/m2. Reductions in diversity may have larger implications regarding ecosystem function and available useable space and densities of desired bird species such as northern bobwhite.

2021 ◽  
Vol 8 ◽  
Author(s):  
Thaiane Weinert da Silva ◽  
Carla Suertegaray Fontana

Since in general the surrounding landscape influences the species diversity and abundance in fragments of native vegetation, an amount of native-vegetation cover nearby may also positively affect communities in restored areas, regardless of the sizes of individual habitat patches. We investigated for the first time whether the species richness, total abundance, and density of grassland birds in restoration sites are influenced by the amount of native grassland in the surrounding landscape in the Brazilian Pampa. We sampled birds by point counts in five restoration sites in the most representative area of grasslands in Brazil. We established an outer buffer zone with a 1 km-radius around the point-count areas in each site, and calculated the percentage of native grassland vegetation in the surrounding landscape. Bird species richness and abundance did not show a significant response to the amount of neighboring native grassland in restored areas. Individual analyses of the density of seven bird species associated to grassland also showed similar pattern. We believe the vegetation structure in these restoration sites may already been sufficiently re-established to provide necessary resources and a suitable habitat for the birds. Even so, we assume that previously existing landscape features were important for recovery of the vegetation structure, as continuous native grassland in the surroundings. Thus, we recommend consider the landscape context as an additional issue in studies dealing with conservation strategies for recovery of grasslands in Brazil.


1998 ◽  
Vol 25 (1) ◽  
pp. 41 ◽  
Author(s):  
Sven R. Sewell ◽  
Carla P. Catterall

Variation in bird assemblages associated with forest clearing and urbanisation in the greater Brisbane area was assessed by counting birds in sites within six habitat categories: large remnants, small remnants, no- understorey remnants, canopy suburbs (original trees present), planted suburbs, and bare suburbs. Total bird abundance and species richness were generally highest in canopy suburbs. Individual species showed many significant abundance differences among the habitat types, and were classified into three major response categories: bushland species (3 in summer, 13 in winter), tolerant species (13 in summer, 13 in winter), and suburban species (12 in summer, 11 in winter). The commonly proposed notion that urbanisation results in lowered bird species richness and increases in introduced species is broadly consistent with the observed differences between bare suburbs and large remnants. However, it does not adequately describe the situation in the planted and canopy suburbs, where there was high species richness and extremely high abundance of some native species (including noisy miners, lorikeets, friarbirds, and butcherbirds) but low abundance of a majority of the species common in the original habitats (including fantails, wrens, whistlers, and other small insectivores). Retained forest remnants are essential for the latter group. Urban plantings of prolifically flowering native species do not reverse the effects of deforestation, but promote a distinctive group of common native suburban bird species. Origins of the urban bird assemblage are discussed.


2021 ◽  
Vol 4 ◽  
Author(s):  
Till-Hendrik Macher ◽  
Robin Schütz ◽  
Jens Arle ◽  
Arne Beermann ◽  
Jan Koschorreck ◽  
...  

Fast, reliable, and comprehensive biodiversity monitoring data are needed for environmental decision making and management. Recent work on fish environmental DNA (eDNA) metabarcoding shows that aquatic diversity can be captured fast, reliably, and non-invasively at moderate costs. Because freshwater ecosystems act as sinks in the landscape, they also collect traces of terrestrial species via surface runoff or when specimens come into direct contact with water (e.g., for drinking purposes). Thus, fish eDNA metabarcoding data can provide information on fish but also on other, even terrestrial vertebrate species that live in riparian habitats. This data become available and may offer a much more comprehensive approach for assessing vertebrate diversity at no additional costs. Studies on how the sampling strategy affects species detection especially of stream-associated communities, however, are scarce. We therefore performed an analysis on the effects of biological replication on both fish as well as (semi-)terrestrial species detection. Along a 2-km stretch of the river Mulde (Germany), we collected 18 1L water samples and analyzed the relation of detected species richness and quantity of biological replicates taken. We detected 58 vertebrate species, of which 25 were fish and lamprey, 18 mammals, and 15 birds, which account for 50%, 24% and 7% of all native species to the German federal state of Saxony-Anhalt. However, while increasing the number of biological replicates resulted in only 25 % more detected fish and lamprey species, mammal and bird species richness increased disproportionately by 69 % and 84 %, respectively. Contrary, PCR replicates showed little stochasticity. We thus emphasize to increase the number of biological replicates when the aim is to improve general species detections. This holds especially true, when the focus is on rare aquatic taxa or on (semi-)terrestrial species, the so-called ‘bycatch’. As a clear advantage, this information can be obtained without any additional sampling or laboratory effort when the sampling strategy regarding biological replication is chosen carefully. With the consideration of frequent eDNA metabarcoding as part of national biomonitoring programs, the additional information provided by the bycatch can be used to further investigate the state of the environment and its biodiversity on a much broader scale.


2021 ◽  
Vol 5 ◽  
Author(s):  
Till-Hendrik Macher ◽  
Robin Schütz ◽  
Jens Arle ◽  
Arne J. Beermann ◽  
Jan Koschorreck ◽  
...  

Fast, reliable, and comprehensive biodiversity monitoring data are needed for environmental decision making and management. Recent work on fish environmental DNA (eDNA) metabarcoding shows that aquatic diversity can be captured fast, reliably, and non-invasively at moderate costs. Because water in a catchment flows to the lowest point in the landscape, often a stream, it can collect traces of terrestrial species via surface or subsurface runoff along its way or when specimens come into direct contact with water (e.g., when drinking). Thus, fish eDNA metabarcoding data can provide information on fish but also on other vertebrate species that live in riparian habitats. This additional data may offer a much more comprehensive approach for assessing vertebrate diversity at no additional costs. Studies on how the sampling strategy affects species detection especially of stream-associated communities, however, are scarce. We therefore performed an analysis on the effects of biological replication on both fish as well as (semi-)terrestrial species detection. Along a 2 km stretch of the river Mulde (Germany), we collected 18 1-L water samples and analyzed the relation of detected species richness and quantity of biological replicates taken. We detected 58 vertebrate species, of which 25 were fish and lamprey, 18 mammals, and 15 birds, which account for 50%, 22.2%, and 7.4% of all native species to the German federal state of Saxony-Anhalt. However, while increasing the number of biological replicates resulted in only 24.8% more detected fish and lamprey species, mammal, and bird species richness increased disproportionately by 68.9% and 77.3%, respectively. Contrary, PCR replicates showed little stochasticity. We thus emphasize to increase the number of biological replicates when the aim is to improve general species detections. This holds especially true when the focus is on rare aquatic taxa or on (semi-)terrestrial species, the so-called ‘bycatch’. As a clear advantage, this information can be obtained without any additional sampling or laboratory effort when the sampling strategy is chosen carefully. With the increased use of eDNA metabarcoding as part of national fish bioassessment and monitoring programs, the complimentary information provided on bycatch can be used for biodiversity monitoring and conservation on a much broader scale.


2019 ◽  
Vol 59 ◽  
pp. e20195934
Author(s):  
Eduardo Chiarani ◽  
Carla Suertegaray Fontana

Parque Estadual do Tainhas – PET (Tainhas State Park) is a protected area with significant extensions of natural grasslands located in highland grasslands of northeastern Rio Grande do Sul state, Brazil, and recognized as an Important Bird Area. Our aim was to record the bird species richness of PET with a greater sampling effort than previous studies at the site, including unpublished data such as occurrence status of most species and evidence of breeding of some of them in the park. We surveyed birds between 2012 and 2018 performing aleatory trails covering mainly the central portion of PET (1,500 ha). We also added records from published studies. We listed 208 species, of which 203 were recorded during our fieldwork (including 18 species of conservation concern). The estimated richness was 222.22 (SD = 10.91) species, according to Jackknife 1 method. This result represents a 58% increase in the species richness of the park and shows that long-term monitoring of the bird community allows to access more accurate richness and to identify the regular species (core avifauna) of the park. The presence of 55 breeders and threatened species shows the importance of this protected area for breeding and conservation of grassland birds, such as Urubitinga coronata, Cinclodes pabsti, Xolmis dominicanus, Anthus nattereri, Xanthopsar flavus, and Sporophila melanogaster.


2021 ◽  
Author(s):  
Till-Hendrik Macher ◽  
Robin Schuetz ◽  
Jens Arle ◽  
Arne J. Beermann ◽  
Jan Koschorreck ◽  
...  

Fast, reliable, and comprehensive biodiversity monitoring data are needed for environmental decision making and management. Recent work on fish environmental DNA (eDNA) metabarcoding shows that aquatic diversity can be captured fast, reliably, and non-invasively at moderate costs. Because water in a catchment flows to the lowest point in the landscape, often a stream, it can often collect traces of terrestrial species via surface or subsurface runoff along its way or when specimens come into direct contact with water (e.g., for drinking purposes). Thus, fish eDNA metabarcoding data can provide information on fish but also on other vertebrate species that live in riparian habitats. This additional data may offer a much more comprehensive approach for assessing vertebrate diversity at no additional costs. Studies on how the sampling strategy affects species detection especially of stream-associated communities, however, are scarce. We therefore performed an analysis on the effects of biological replication on both fish as well as (semi-)terrestrial species detection. Along a 2 km stretch of the river Mulde (Germany), we collected 18 1-L water samples and analyzed the relation of detected species richness and quantity of biological replicates taken. We detected 58 vertebrate species, of which 25 were fish and lamprey, 18 mammals, and 15 birds, which account for 50%, 24%, and 7% of all native species to the German federal state of Saxony-Anhalt. However, while increasing the number of biological replicates resulted in only 25% more detected fish and lamprey species, mammal, and bird species richness increased disproportionately by 69% and 84%, respectively. Contrary, PCR replicates showed little stochasticity. We thus emphasize to increase the number of biological replicates when the aim is to improve general species detections. This holds especially true, when the focus is on rare aquatic taxa or on (semi-)terrestrial species, the so-called 'bycatch'. As a clear advantage, this information can be obtained without any additional sampling or laboratory effort when the sampling strategy is chosen carefully. With the increased use of eDNA metabarcoding as part of national fish bioassessment and monitoring programs, the complimentary information provided on bycatch can be used for biodiversity monitoring and conservation on a much broader scale.


Forests ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 92
Author(s):  
Ana Mariscal ◽  
Mulualem Tigabu ◽  
Patrice Savadogo ◽  
Per Christer Odén

The importance of forests for biodiversity conservation has been well recognized by the global community; as a result, conservation efforts have increased over the past two decades. In Ecuador, the lack of integrated information for defining and assessing the status of local ecosystems is a major challenge for designing conservation and restoration plans. Thus, the objectives of this study were (1) to examine the regeneration status of cloud forest remnants, some of which had experienced past human disturbance events, (2) to explore a local rural community’s traditional ecological knowledge (TEK) relevant for restoration and (3) to investigate the integration between TEK and ecological science-based approaches. A survey of regeneration status was conducted in four remnants of cloud forests (n = 16) in Cosanga, Napo Province, in the Andes of northeastern Ecuador. The species of young trees (0.5–5 m height) were identified over 0.16 ha. In-depth interviews of individuals from local communities (n = 48) were conducted to identify socio-ecologically important native species. The results showed significant differences (p < 0.001) in species richness and the stem density of seedlings and saplings in gaps. The stem density of Chusquea sp., a bamboo species, explained 63% of the variation in species richness and 48% of the variation in the abundance of seedlings and saplings between plots. Informants cited 32 socio-ecologically important species, of which 26 species were cited as sources of food and habitats for wildlife. The ranking of species based on a relative importance index and a cultural value index—taking into account both the spread of knowledge among local informants and the multiplicity of uses—revealed that Hyeromina duquei, Citharexylum montanum, Eugenia crassimarginata and Sapium contortum were traditionally the most valuable species for both humans and wildlife. Informants also recommended 27 species for future planting, of which 19 species were amongst the rarest species in the regeneration survey. In conclusion, the results demonstrate a synergy between TEK and ecological science-based approaches (regeneration survey) to natural ecosystem research. Thus, traditional ecological knowledge can provide insights into ecosystem–plant–animal interaction, and to identify native species useful for both humans and wildlife for forest restoration projects to reconnect isolated cloud forest fragments.


2019 ◽  
Author(s):  
Federico Morelli ◽  
Yanina

ContextThe negative association between elevation and species richness is a well-recognized pattern in macro-ecology. ObjectivesThe aim of this study was to investigate changes in functional evenness of breeding bird communities along an elevation gradient in Europe. MethodsUsing the bird data from the EBCC Atlas of European Breeding Birds we estimated an index of functional evenness which can be assumed as a measure of the potential resilience of communities.ResultsOur findings confirm the existence of a negative association between elevation and bird species richness in all European eco regions. However, we also explored a novel aspect of this relationship, important for conservation: Our findings provide evidence at large spatial scale of a negative association between the functional evenness (potential community resilience) and elevation, independent of the eco region. We also found that the Natura2000 protected areas covers the territory most in need of protection, those characterized by bird communities with low potential resilience, in hilly and mountainous areas.ConclusionsThese results draw attention to European areas occupied by bird communities characterized by a potential lower capacity to respond to strong ecological changes, and, therefore, potentially more exposed to risks for conservation.


2020 ◽  
pp. 1-16
Author(s):  
S. THOBEKA GUMEDE ◽  
DAVID A. EHLERS SMITH ◽  
YVETTE C. EHLERS SMITH ◽  
SAMUKELISIWE P. NGCOBO ◽  
MBALENHLE T. SOSIBO ◽  
...  

Summary Establishing the specific habitat requirements of forest specialists in fragmented natural habitats is vital for their conservation. We used camera-trap surveys and microhabitat-scale covariates to assess the habitat requirements, probability of occupancy and detection of two terrestrial forest specialist species, the Orange Ground-thrush Geokichla gurneyi and the Lemon Dove Aplopelia larvata during the breeding and non-breeding seasons of 2018–2019 in selected Southern Mistbelt Forests of KwaZulu-Natal and the Eastern Cape, South Africa. A series of camera-trap surveys over 21 days were conducted in conjunction with surveys of microhabitat structural covariates. During the wet season, percentage of leaf litter cover, short grass cover, short herb cover, tall herb cover and saplings 0–2 m, stem density of trees 6–10 m and trees 16–20 m were significant structural covariates for influencing Lemon Dove occupancy. In the dry season, stem density of 2–5 m and 10–15 m trees, percentage tall herb cover, short herb cover and 0–2 m saplings were significant covariates influencing Lemon Dove occupancy. Stem density of trees 2–5 m and 11–15 m, percentage of short grass cover and short herb cover were important site covariates influencing Orange Ground-thrush occupancy in the wet season. Our study highlighted the importance of a diverse habitat structure for both forest species. A high density of tall/mature trees was an essential microhabitat covariate, particularly for sufficient cover and food for these ground-dwelling birds. Avian forest specialists play a vital role in providing ecosystem services perpetuating forest habitat functioning. Conservation of the natural heterogeneity of their habitat is integral to management plans to prevent the decline of such species.


Author(s):  
Robert Patchett ◽  
Alexander N. G. Kirschel ◽  
Joanna Robins King ◽  
Patrick Styles ◽  
Will Cresswell

AbstractFemale song is widespread across bird species yet rarely reported. Here, we report the first observations and description of female song in the Cyprus Wheatear Oenanthe cypriaca and compare it to male song through the breeding season. Twenty-five percent of colour-ringed females were observed singing at least once, predominantly in April, compared to 71% of males that continued singing through the breeding period. We suggest that female song may have multiple functions in this species, but it may be especially important in territorial defence and mate acquisition.


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