How does a Psittacanthus robustus Mart. population structure relate to a Vochysia thyrsoidea Pohl. host population?

Published Date

December 2010, Vol.205(12):797–801, doi:10.1016/j.flora.2010.04.013

Title 

How does a Psittacanthus robustus Mart. population structure relate to a Vochysia thyrsoidea Pohl. host population?

• Author 

• Grazielle Sales Teodoro ^,
• Eduardo van den Berg 
• Marcela de Castro Nunes Santos 
• Flávia de Freitas Coelho 

• Setor de Ecologia (Ecology Section), Departamento de Biologia (Biology Department), Universidade Federal de Lavras, UFLA (Federal University of Lavras), Campus Universitário, Caixa Postal 3037, CEP 37200-000 Lavras, Minas Gerais, Brazil

Received 31 July 2009. Accepted 30 November 2009. Available online 18 June 2010.

Abstract

Distribution of parasitic plants is directly linked with the distribution of host species and behavioral patterns of seed dispersers. Psittacanthus robustus (Loranthaceae) is a neotropical hemiparasite that mainly colonizes species of the family Vochysiaceae. Vochysia thyrsoidea is the main host of P. robustus and is commonly found in areas of cerrado rupestre (rocky savanna), an abundant vegetation in our study site. We conducted the study in the ecological park Parque Ecológico Quedas do Rio Bonito (PEQRB), over an area of 2.82 ha of cerrado rupestre. The objective of this work was to investigate population structure, parasitic behavior (mistletoe grip height and circumference of host branch), and spatial distribution of Psittacanthus robustus on a population of Vochysia thyrsoidea. We sampled 267 V. thyrsoidea individuals and found that the population had a random distribution pattern. Seventy-nine individuals (29.6% of the sample population) hosted the hemiparasite, to a total of 193 P. robustus individuals. The number of mistletoe individuals per host plant ranged between 1 and 12. The V. thyrsoidea individuals most infested with mistletoes were those reaching greater heights. The correlation between height of host plant and preferred grip height was highly significant, with the preferred grip height being the uppermost portions of host plants. The crown size of P. robustus individuals ranged between 10 and 230 cm. The main disperser of P. robustus fruit was found to be swallow-tanager Tersina viridis viridis. Its activities led to a clumped pattern of spatial distribution of the hemiparasite along with higher infestation in larger trees.

Keywords

Hemiparasite

Host

Loranthaceae

Vochysiaceae

Plant dispersal

Cerrado

---

Fig. 1.

Fig. 2.

 Table 1

Table 1.

Fig. 3.

Fig. 4.

Fig. 5.

Fig. 6.

Fig. 7.

• ⁎ 
  Corresponding author. Tel.: +55 35 38213207.

For further details log on website :
http://www.sciencedirect.com/science/article/pii/S0367253010000629