  Let $k$ be a field and $R=k[x_1,\ldots,x_n]/I=S/I$ a graded ring. Then $R$
has a $t$-linear resolution if $I$ is generated by homogeneous elements of
degree $t$, and all higher syzygies are linear. Thus $R$ has a $t$-linear
resolution if ${\rm Tor}^S_{i,j}(S/I,k)=0$ if $j\ne i+t-1$.
  For a simplicial complex $\Delta$ on $[{\bf n}]=\{1,\ldots,n\}$ and a field
$k$, the Stanley-Reisner ring $k[\Delta]$ is $k[x_1,\ldots,x_n]/I$, where $I$
is generated by those squarefree monomials $x_{i_1}\cdots x_{i_k}$ for which
$\{ i_1,\ldots,i_k\}$ does not belong to $\Delta$.
  In \cite{Fr} the Stanley-Reisner rings with 2-linear resolution are
determined. Their associated complexes has had different names in the
literature. We call them fat forests here. In this article we determine the
Betti numbers of fat forests. We also consider Betti numbers of Alexander duals
of fat forests.
