Fragmentation of Coastal Grasslands by Plantations and Spontaneous Spread of Invasive Pines in the Southern Pampa

Coastal dunes of the southern Buenos Aires province, in Argentina, are one of the last remnants of biodiversity in the southern Pampa unit, within the Rio de la Plata Grasslands. While the direct loss of grasslands due to the advance of cities and afforestation is conspicuous, the negative effects of the subdivision of the remaining environments on biodiversity and ecosystem dynamics are less considered. Our work aimed to analyze the combined effect of fires and subdivision of grasslands by invasive alien trees. Our results suggest that fragmentation affects the resilience of coastal grasslands after fire and affects the course of succession, promoting the establishment of invasive alien plants. We also suggest that fires favor the advance of pines and acacias towards the interior of grassland remnants, further reducing their area. The effective conservation of the components of Pampas biodiversity that still persist in these coastal ecosystems will depend on preventing, mitigating and compensating the insularization effects associated with forest plantations and the expansion of invasive trees, by means of adequate territorial planning that allows remnants to be maintained in a good state of conservation.

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Co-occurrence, habitat use and activity pattern of carnivore species in a coastal area of Argentina

10.1101/2020.03.04.976415 ◽

2020 ◽

Author(s):

N.C. Caruso ◽

E.M. Luengos Vidal ◽

M.C. Manfredi ◽

M.S. Araujo ◽

M. Lucherini ◽

...

Keyword(s):

Habitat Use ◽

Coastal Area ◽

Activity Pattern ◽

Buenos Aires ◽

Coastal Dunes ◽

Terrestrial Ecosystems ◽

Buenos Aires Province ◽

Infrastructure Development ◽

Mobile Species ◽

Carnivore Species

AbstractLand-sea interface is an ecotone where the intersection of marine and terrestrial ecosystems create unique ecological conditions for terrestrial mobile species and freshwater-adapted organisms to exploit marine-derived food resources. Mammalian carnivores play an important role in almost any ecosystem where they live due to their top-down (or trophic cascade) effects on prey species and primary producers, thus structuring ecosystems along varied food-web pathways. We use camera trapping to study the patterns of coexistence, habitat use and activity pattern of carnivores species in a coastal area in southern Buenos Aires province, Argentina. We were able to detect five of the seven species of Mammalian carnivores being the Pampas fox Lycalopex gymnocercus and Geoffroy’s cat Leopardus geoffroyi the two most common. Geoffroy’s cat seems to use more intensively those areas close to the shoreline, while we found little support of it for Pampas fox; which seems to use more inland areas. Congruently, we found evidence of a lack of spatial and, to a lower extent, temporal avoidance between the two most common carnivore species of our study area. Our findings support those previous studies indicating that the coastal dunes have an important role in the conservation of the biodiversity of Buenos Aires province. Wildlife conservation is compatible with carefully-designed ecotourism and limited infrastructure development and this may be a unique chance for the areas of Buenos Aires coast that have not been affected yet by poorly planned, conservation-unfriendly urbanization.

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DIFFUSE TERMITINAE NESTS SHED LIGHT ON THE AFFINITIES OF LAETOLICHNUS KWEKAI (KRAUSICHNIDAE)

Palaios ◽

10.2110/palo.2020.057 ◽

2021 ◽

Vol 36 (3) ◽

pp. 122-127

Author(s):

LILIANA F. CANTIL ◽

JORGE F. GENISE ◽

JUAN L. FARINA ◽

SEBASTIÁN LUPO ◽

DARÍO PORRINI ◽

...

Keyword(s):

Buenos Aires ◽

Complex Structure ◽

Coastal Dunes ◽

Field Studies ◽

Buenos Aires Province ◽

South American ◽

First Time ◽

New Evidence ◽

Semiarid Shrublands ◽

Shed Light

ABSTRACT The insect trace fossil Laetolichnus kwekai, which is composed of a small chamber extending to slender cylinders at each end, was tentatively included in the ichnofamily Krausichnidae as termite nests. New evidence presented here provides information to validate these inferences. A more complex structure formed by interconnected Laetolichnus was recently found in the same Pliocene deposits (Laetoli, Tanzania) as the isolated specimens reported previously. Our study confirms inclusion of Laetolichnus in Krausichnidae and supports the inference that it represents a nest of a social insect. Neoichnological field studies in the coastal dunes of Buenos Aires Province, Argentina, were undertaken to refine further the nature of these affinities. Survey of the dune surface revealed abundant loose fragments of termite nests of a size and shape comparable to that of L. kwekai. The fragile nests constructed by Onkotermes brevicorniger, which are described here in detail for the first time, enable us to interpret the fossil structures. They consist of connected chambers similar to the interconnected Laetolichnus. These were frequently exposed and broken by wind action resulting in loose fragments similar to the isolated Laetolichnus. The Celliforma ichnofacies represented at Laetoli, which contains L. kwekai, indicates arid or semiarid shrublands and woodlands. The distribution of O. brevicorniger also corresponds to arid and semiarid shrublands and dry woodlands of Argentina. Although the African termite producer of L. kwekai and the South American Onkotermes would be phylogenetically unrelated, the analogous structures probably reflect convergent nesting behaviors as an adaptation to similar arid to semiarid environmental conditions.

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Pollen deposition in coastal dunes, south Buenos Aires Province, Argentina

Review of Palaeobotany and Palynology ◽

10.1016/s0034-6667(03)00034-4 ◽

2003 ◽

Vol 126 (1-2) ◽

pp. 17-37 ◽

Cited By ~ 11

Author(s):

Sonia L Fontana

Keyword(s):

Buenos Aires ◽

Coastal Dunes ◽

Pollen Deposition ◽

Buenos Aires Province

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Herpetofauna, Coastal Dunes, Buenos Aires Province, Argentina

Check List ◽

10.15560/2.3.15 ◽

2006 ◽

Vol 2 (3) ◽

pp. 15 ◽

Cited By ~ 9

Author(s):

Federico Kacoliris ◽

Nathalie Horlent ◽

Jorge Williams

Keyword(s):

Habitat Loss ◽

Human Activities ◽

Buenos Aires ◽

Conservation Status ◽

Coastal Dunes ◽

Field Work ◽

Coastal Dune ◽

Conservation Strategies ◽

Buenos Aires Province ◽

Loss Process

Coastal dunes habitats at Buenos Aires province are in a fragmentation and habitat loss process due to related human activities. Knowledge on the herpetofauna of Buenos Aires province coast habitats is plentiful for some species of lizards and scarce for most amphibians and snakes. With the aim to present a list on the amphibians and reptiles of the coastal dune habitats in Buenos Aires province we recorded species coming from field work, cited in literature, and vouchers specimens deposited in herpetological collections. We recorded 35 species in six sectors that represent the last remnants of coastal dunes in good conservation status. The Mar Chiquita and Faro Querandí Reserves represent an important contribution to the conservation of several species that inhabit coastal dune habitats. It is necessary to increase the knowledge on biodiversity in those habitats in order to develop conservation strategies.

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