Phenology of Zamia boliviana (Zamiaceae) , a threatened species from a seasonally dry biodiversity hotspot in South America

Author(s):  
Rosane Segalla ◽  
Fábio Pinheiro ◽  
Gudryan J. Baronio ◽  
Leonor Patrícia Cerdeira Morellato
Hoehnea ◽  
2018 ◽  
Vol 45 (2) ◽  
pp. 238-306 ◽  
Author(s):  
Rafael Felipe de Almeida

ABSTRACT The taxonomic revision of Amorimia (Malpighiaceae) is presented, including typifications, and descriptions for all accepted species. The genus is endemic to Seasonally Dry Tropical Forests and Rainforests of South America, and its species can be distinguished by morphological details of leaves, indumenta, inflorescences, flowers, and fruits. This study includes an identification key for the subgenera and species of Amorimia, illustrations, distribution maps, conservation risk assessments, and comments on ecology, nomenclature, and taxonomy for all species. Additionally, I provide a key to differentiate Amorimia from the remaining genera of the Malpighioid clade.


1998 ◽  
Vol 4 (1) ◽  
pp. 33 ◽  
Author(s):  
A. J. Stattersfield

The first application of the new IUCN threatened species categories to birds is reviewed. The advantage of this system is that it is characterized by clear, objective, quantitative criteria. However, for many species, requisite numerical data are lacking, and the magnitude of potential threats has to be inferred. Numbers of threatened species are compared for South America, sub-Saharan Africa, and Indo-Pacific Islands. Further analysis identifies the most important countries in terms of priority for conservation action for threatened species, the key habitats for their survival and the main dangers faced. The changes between successive Red Lists indicate a possible extinction crisis of considerable magnitude, whereby half the world's birds could disappear in 800 years. Averting this crisis requires identifying and protecting sites where suites of threatened species co-occur.


2020 ◽  
Author(s):  
Milena Godoy-Veiga ◽  
Giuliano Locosselli ◽  
Lior Regev ◽  
Elisabetta Boaretto ◽  
Gregório Ceccantini

<p>Tree-ring chronologies are an excellent climate archive for their spatial and temporal resolution. While networks of chronologies have been built outside the tropics helping to understand past regional climate trends, tropical regions still lag behind in terms of spatial coverage. Dendrochronological studies, however, may succeed in seasonally dry tropical forests where the growing season is well defined. <em>Amburana cearensis</em>, found in both dry and wet forests in South America, is poorly explored for dendrochronological purposes, with no previous study in Brazil. Therefore, we sampled trees growing in a seasonally dry forest in a karstic area in Central-Eastern Brazil, under the South American Monsoon domain, in order to explore this species potential for dendroclimatological studies in the region. We build a tree-ring width chronology using 26 trees. We found a strong common growth signal among trees, with an r-bar of 0.51 and an average mean sensitivity of 0.50. The standard tree-ring width chronology showed a significant negative correlation with Vapor-Pressure Deficit during the entire wet season (0.54), negative correlation with temperature at the end of the wet season (0.45), and a positive correlation with the sum of precipitation during the wet season (0.46). Further stable isotopic analysis will provide additional records of climate variability in the region. Since Amburana cearensis occurs across most of the seasonally dry forests and savannas from South America, it has a great potential to be used to develop climate reconstructions and verify the effects of climate change currently affecting the region.</p>


2015 ◽  
Vol 177 (2) ◽  
pp. 189-201 ◽  
Author(s):  
Fábio de Almeida Vieira ◽  
Renan Milagres Lage Novaes ◽  
Cristiane Gouvêa Fajardo ◽  
Rubens Manoel dos Santos ◽  
Hisaias de Souza Almeida ◽  
...  

2018 ◽  
Vol 66 (2) ◽  
pp. 134 ◽  
Author(s):  
Erica Shedley ◽  
Neil Burrows ◽  
Colin J. Yates ◽  
David J. Coates

Inappropriate fire-regimes brought about by patterns of human settlement and land-use threaten plant diversity in Mediterranean-type climate (MTC) regions. In south-west Western Australia (SWWA), where there are many threatened plant species distributed across a range of human-modified landscapes, there is a need for approaches to identify where the threat is greatest. This requires knowledge of contemporary fire regimes, how they vary across landscapes, and the sensitivity of threatened species to these regimes. Currently, this information is lacking, and this limits strategic fire management. In this study we compiled fire response information for SWWA’s threatened plant species and undertook a bioregional assessment of variation in fire interval over the last 40 years. We determined the fire response traits of 242 (60%) of the region’s 401 extant threatened species. Over half of the 242 species were obligate seeders and will therefore have population dynamics particularly sensitive to fire interval. Our study highlights large differences in fire interval across nine bioregions in SWWA. The differences were greatest for the heavily cleared and fragmented bioregions compared with more continuously vegetated bioregions. We discuss how variations in the frequency of fire life-history traits and fire interval interact to determine the nature and relative level of threat posed by fire in these landscapes. Survival of many populations of threatened flora in this biodiversity hotspot will depend on developing appropriate fire regimes that match the regeneration requirements of each species.


2021 ◽  
Vol 15 (1) ◽  
pp. 73-111
Author(s):  
D.G. Debouck

This work presents an updated list of the species belonging to the genus Phaseolus following its definition of 1978; it is the outcome of the study of eighty-six herbaria and forty-one explorations in the field in the period 1978–2019. There are currently eighty-one species, all of them native to the Americas, most of them distributed north of Panama (the genus is a migrant into South America), and half of them being known by very few records. They thrive in warm to mild temperate, seasonally dry, open forest, with rains under favorable temperature, from sea level up to 3,000 m. The recent increase in the number of recognized species is due to the endemic ones; this in combination with few unclassified specimens may indicate that the total number of species is not final yet, and that field work will be rewarding.


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