Living tree “8,000 years older than Christ”?

“A group of Huon pines in Tasmania has been claimed as the oldest living organism. Scientists have “dated” the tree at “more than 10,500 years old.” From the creationist perspective, it is not possible that any trees much older than 4,500 years could exist since the catastrophic nature of the Flood would most likely have removed all vegetation from the surface of the earth. The age of the group of trees, which are clones based on DNA samples, was not determined by ring counts, but by the presence of pollen in samples drilled from a nearby lake. Traditional tree-ring dates give ages of no more than 4,000 years. This is close to the oldest bristlecone pines from the Rocky Mountains, which have 4,600 rings. The fact that the ages for the Huon pines are estimated from pollen in a nearby lake means the dates are based on many assumptions. One scientist associated with the study noted that the media had run the story prematurely and that the claim was not yet substantiated. Tree dating involves many assumptions, but the fact that the oldest known dates are near 4,500 years confirms the date of the global Flood described in Genesis. Apart from the Flood, there is no reason why trees older than 4,500 years should not be alive today.” Evolution Exposed, Second Ed., Living tree “8,000 years older than Christ”? www.answersingenesis.org/creation/v17/i3/living_tree.asp

Response to comment [from a "Christian"]:  "Oops guess the Methuselah tree is a bit of a problem then at 4841 years. Oh and Prometheus that was 4,844 years old in 1964..."

How do scientists explain the fact that no individual trees are found to be older than about 4,500 years (give or take a few years)?

Grass is not supposed to have evolved until after the dinosaurs became extinct, why is grass found in dinosaur dung?

Living tree “8,000 years older than Christ”?