1. The invasion of Santa Cruz highland by exotic quinine tree (Cinchona pubescens)
  2. Changes in Scalesia pedunculata forest around the collapsed crater in Los Gemelos

A:Changes in the highland Fern-Sedge vegetation around Puntudo over 30 years,due to
invasion by exotic quinine trees.
1 ) No.774

1970. Natural vegetation before invasion by quinine trees
2 ) No.775

1991. Slight invasion by quinine trees
3 ) No.1363

2001. Quinine tree community developed

B:Vegetation changes on Mt. Media Luna in the last 30 years,invasion and eradication
of naturalized quinine trees
1 ) No.584

1978. Media Luna covered purely by Miconia robinsoniana before the invasion by quinine trees
2 ) No.585

1995. Invasion by quinine trees visible
3 ) No.586

1998. Quinine trees prominent and mixed with M. robinsoniana
4 ) NO.588

2001. Quinine trees eradicated in 1999 by the Galapagos National Park Service and the Charles Darwin Research Station.

Oceanic islands that have not been connected to any continent and landmass intrinsically have a limited number of tree species and are susceptible to invasion by exotic tree species. The quinine tree has been introduced into the Galapagos. This species is native to the Andean region and a raw material plant for strychnine, a medicine for malaria. It is said that early settlers in Santa Cruz did not know the natural conditions of the Galapagos and brought this species in for malaria. This plant produces airborne seeds. There was no quinine tree in the highland in the 1970s. The seed was dispersed there in the 1980s and the tree spread over the highland in the 1990s. The quinine tree was naturalized only on Santa Cruz before 2006.

  • Pict A :The Fern-Sedge zone, where quinine trees became visible early in the 1990s, converted to a quinine-dominated vegetation around 2000.
  • Pict B :Quinine trees became noticeable on Mt. Media Luna, which had been covered with Miconia robinsoniana communities, around 1995. The Charles Darwin Research Station and the Galapagos National Park Service eradicated quinine trees from the Miconia communities on Mount Media Luna in 1999.

A:Changes of Scalesia forest on the opposite side of the collapsed crater in Los Gemelos,
before and after the 1982-83 El Nino.
No.74

1981. Scalesia forest before El Nino
No.75

1986. Regenerated community in the 3rd year after El Nino
No.76

1987. Regenerated communities in the 4th year after El Nino
NO.77

1991. Communities in the 8th year after El Nino
NO.78

1995. Communities in the 12th year after El Nino

B:Mature stages, and the regeneration process of Scalesia forest before and after the
1982 - 83 El Nino.
1 ) No.71

1981, Appearance of well developed Scalesia forest
2 ) No.72

1981, Inside of forest
3 ) No.80

1986, Regenerating cohort after massive dieback in 1983

The genus Scalesia, Compositae, is endemic to Galapagos. All the 15 species are arboreous plants: 12 shrubs and three high trees. Scalesia pudunculata is the biggest high tree and reaches 25 centimeters in trunk diameter and 12 meters in height. This species is distributed on islands from the eastern part to the central part of the archipelago, such as San Cristobal, Floreana, Santa Cruz, and Santiago, and formed dense forests in moist mid-elevations. The dense forest usually suffers massive dieback triggered by extremely dry weather and extremely heavy rains.
On Santa Cruz Island, dense forests of this species were found in mesic, fertile land halfway up hills. Many of the forests were converted to farmland and residential areas, but natural forests still remained in the Los Gemelos area, where Scalesia forests suffered massive dieback when El Nino occurred in 1982-83. Immediately after the dieback, regeneration began uniformly the following year.