If you read Orac’s blog, Respectful Insolence, you would have seen the post, Requiem for a friend I’ve never met. I too “knew” Mark. I’ve been trading emails with him for a few years now. I’ve never met him in person, or even heard his voice.
Mark was a fighter. He was fighting the good fight before I even knew about it. Mark was working to make life better for my kid before I had a kid. He was intensely proud of his kids.
Mark’s son let a comment on Liz Ditz’ facebook page:
Please plant a tree in my dads honor in Israel. He would want that to show a sign of growth. Thank you
I took Liz’s suggestion and made a donation to the Jewish National Fund.
Farewell Mark. I wish your family peace in these times.
Left Brain Right Brain 
“Bulldozers returned to the village of al-Araqib in the northern Negev on Wednesday, 4 August, and demolished approximately ten new structures residents and supporters had built a week after Israeli forces completely destroyed the village on 27 July.”
“The Jewish National Fund (JNF) plans to build a forest on the land of al-Araqib. The majority of villagers still live in tents on their land, and the Palestinian news agency Ma’an reported that locals said they will keep rebuilding their homes. The JNF, a para-state institution, has worked since before the establishment of the State of Israel to erase and appropriate Palestinian land.”
from http://electronicintifada.net/v2/article11445.shtml
So no, I wont plant a tree in Israel, nor will I donate to the JNF